Biology Clep

Front 1

Zygote

Back 1

Fertilzed egg.

Front 2

Yolk Sac

Back 2

Store nutrients for use by the embryo.

Front 3

Xylem

Back 3

The supporting and water-conducting tissue of vascular plants, consisting primarily of tracheids and vessels; woody tissue.

Front 4

Phloem

Back 4

The food-conducting tissue of vascular plants, consisting of sieve tubes, fibers, parenchyma, and sclereids. Also called bast.

Front 5

White Matter

Back 5

Whitish nerve tissue, especially of the brain and spinal cord, consisting chiefly of myelinated nerve fibers.

Front 6

Watson-Crick

Back 6

Discovered and modeled the double-helix DNA structure.

Front 7

Water Cycle

Back 7

The cycle of evaporation and condensation that controls the distribution of the earth's water as it evaporates from bodies of water, condenses, precipitates, and returns to those bodies of water.

Front 8

Visceral Sensory Nerves

Back 8

Carry impulses from body organs to the cetneral nervous sytem.

Front 9

Virus

Back 9

Any of various simple submicroscopic parasites of plants, animals, and bacteria that often cause disease and that consist essentially of a core of RNA or DNA surrounded by a protein coat. Unable to replicate without a host cell, viruses are typically not considered living organisms.

Front 10

Villi

Back 10

Tiny, finger-like projections that protrude from the epithelial lining of the intestinal wall and increase the surface area of the intestinal wall. Increased surface area allows for increased intestinal wall area that is available for absorption.

Front 11

Vessels

Back 11

Part of the circulatory system that transports blood throughout the body.

There are three major types: the arteries, which carry the blood away from the heart; the capillaries, which enable the actual exchange of water and chemicals between the blood and the tissues; and the veins, which carry blood from the capillaries back toward the heart.

Front 12

Vertebrates

Back 12

Animals with internal backbone.

Front 13

Vertebrata

Back 13

The major subphylum of the phylum Chordata including all animals with backbones, from fish to human.

Front 14

Venules

Back 14

A small vein, especially one joining capillaries to larger veins.

Front 15

Veins

Back 15

Carry blood to the heart.

Front 16

Vegetative Propagation

Back 16

The ability of plants to reproduce without sexual reproduction, by producing new plants from existing vegetative structures.

Front 17

Vascular Tissue

Back 17

The supportive and conductive tissue in plants, consisting of xylem and phloem.

Front 18

Vascular Bundles

Back 18

A strandlike part of the plant vascular system containing xylem and phloem.

Front 19

Vascular Cylinder

Back 19

The center of the root, made up of both xylem and phloem tissue.

Front 20

Vascular Plants

Back 20

Any of various plants, such as the ferns and seed-bearing plants, in which the phloem transports sugar and the xylem transports water and salts.

Front 21

Valence Shell

Back 21

The outermost shell of an atom. It is usually said that the electrons in this shell make up its valence electrons, that is, the electrons that determine how the atom behaves in chemical reactions.

Front 22

Uterus

Back 22

A hollow muscular organ located in the pelvic cavity of female mammals in which the fertilized egg implants and develops. Also called womb.

Front 23

Urochordata

Back 23

Subphylum of the Chordata characterized by restriction of the notochord to the tail and posterior body of the larva, absence of mesodermal segmentation, and secretion of an outer covering or tunic about the body.

Front 24

Urine

Back 24

The waste product secreted by the kidneys that in mammals is a yellow to amber-colored, slightly acid fluid discharged from the body through the urethra.

Front 25

Umbilical Cord

Back 25

The flexible cordlike structure connecting a fetus at the abdomen with the placenta and containing two umbilical arteries and one vein that transport nourishment to the fetus and remove its wastes.

Front 26

T cells

Back 26

Key to the immune system, these cells originate in the bone marrow but mature in the thymus. T-cells attack other body cells that are infected by some bacteria, a virus, or another pathogens.

Front 27

Taxes (Taxis)

Back 27

Directional response either toward or away from a stimulus.

Front 28

Taxonomy

Back 28

The classification of organisms in an ordered system that indicates natural relationships.

Front 29

Telophase

Back 29

The nuclear membrane forms around chromosomes, the chromosomes are no longer visible under a standard microscope, and the spindle fibers disappear.

Front 30

Terminal Bud

Back 30

A bud that develops at the apex of a stem. Also known as apical bud.

The beginning of a new set of leaves.

Front 31

Terminal Bud Scar

Back 31

The location where the previous years terminal bud was located, also known as an annual growth ring.

Front 32

Terrestrial Biomes

Back 32

Biomes that exist on land.

Front 33

Territory

Back 33

An area occupied by a single animal, mating pair, or group and often vigorously defended against intruders, especially those of the same species.

Front 34

Thalamus

Back 34

A large ovoid mass of gray matter situated in the posterior part of the forebrain that relays sensory impulses to the cerebral cortex.

Front 35

Third Trophic Level

Back 35

First level of carnivores.

Carnivores, which eat herbivores.

Front 36

Thymus

Back 36

A small glandular organ that is situated behind the top of the breastbone, consisting mainly of lymphatic tissue and serving as the site of T cell differentiation. The thymus increases gradually in size and activity until puberty, becoming vestigial thereafter.

Front 37

Tissues

Back 37

An aggregation of morphologically similar cells and associated intercellular matter acting together to perform one or more specific functions in the body. There are four basic types of tissue: muscle, nerve, epidermal, and connective.

Front 38

Tonoplast

Back 38

The cytoplasmic membrane that surrounds a vacuole of a plant cell. Also called vacuolar membrane.

Front 39

Tonsils

Back 39

A small oral mass of lymphoid tissue, especially either of two such masses embedded in the lateral walls of the opening between the mouth and the pharynx, of uncertain function, but believed to help protect the body from respiratory infections.

Front 40

Trachea

Back 40

A thin-walled, cartilaginous tube descending from the larynx to the bronchi and carrying air to the lungs. Also called windpipe.

Front 41

Transcription

Back 41

The process by which messenger RNA is synthesized from a DNA template resulting in the transfer of genetic information from the DNA molecule to the messenger RNA.

Front 42

Transduction

Back 42

Transfer of genetic material or characteristics from one bacterial cell to another by the incorporation of bacterial DNA into a bacteriophage.

Front 43

Transformation

Back 43

The alteration of a bacterial cell caused by the transfer of DNA from another bacterial cell, especially a pathogen.

Front 44

Translation

Back 44

The process by which messenger RNA directs the amino acid sequence of a growing polypeptide during protein synthesis.

Front 45

Transpiration

Back 45

Evaporation, especially through the stomata of plant tissue or the pores of the skin.

Front 46

Trisaccharide

Back 46

Composed of three monosaccharides with two glycosidic bonds connecting them
together.

Front 47

tRNA

Back 47

Transfer RNA.

Link between the language to nucleotides, and the language of amino acids.

Front 48

Trophic Levels

Back 48

Steps in the food chain.

Front 49

Tropism

Back 49

The turning or bending movement of an organism or a part toward or away from an external stimulus, such as light, heat, or gravity.

Front 50

Tubers

Back 50

A swollen, fleshy, usually underground stem of a plant, such as the potato, bearing buds from which new plant shoots arise.

Front 51

S Phase

Back 51

The second phase of interphase where the cell begins to prepare for cell division by replicating DNA and proteins necessay to form a new set of chromosomes.

Front 52

Salivary Glands

Back 52

A gland that secretes saliva, especially any of three pairs of large glands, the parotid, submaxillary, and sublingual, whose secretions enter the mouth and mingle in saliva.

Front 53

Second Trophic Level

Back 53

Animals that eat plants and are called primary consumers. Also known as herbivores.

Front 54

Secondary Oocyte

Back 54

Result of primary oocytes that have gone through meosis I.

Front 55

Secretory Vesicles

Back 55

Packets of material packaged by the Golgi apparatus or the endoplasmic reticulum that carry substances to produced within the cell to the cell membrane.

Front 56

Seed

Back 56

Contains a tiny embryonic plant, stored food, and a coat for protection.

Front 57

Sensory Organs

Back 57

Skin, eyes, nose, ears, ect.

Front 58

SER

Back 58

Smooth Endoplasmic Reticulum

Front 59

Sex Influenced

Back 59

Autosomal traits that are influenced by sex. If a male has one recessive allele, he will show that trait, but it will take two recessive for the female to show that same trait. One such gene is baldness.

Front 60

Sex Limited Trait

Back 60

Genes which are present in both sexes of sexually reproducing species but turned on in only one sex. In other words, the genes cause the two sexes to show different traits or phenotypes.

Front 61

Sex Linked

Back 61

The linkage of a gene producing a certain phenotype (often unrelated to primary or secondary sexual characters) with a sex chromosome (usually an X chromosome). Mutation of genes on the X chromosome is often apparent only in male offspring, which have only one X chromosome. The mutation may be masked in the female unless the mutation also occurs on the other X chromosome.

(Examples: Hemophilia, Color Blindness)

Front 62

Shoot Apex

Back 62

Region where ellongation of the tem occurs.

Front 63

Sieve Plates

Back 63

The perforated transverse wall between two cells in vascular plants (Angiosperms).

Front 64

Simple Fruits

Back 64

A fruit, such as a pea pod, orange, or tomato, apple, corn, olive, acorn, cucumber that develops from a single pistil/ovary.

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Skeletal Muscles

Back 65

Attach to the bones and enable voluntary movement.

Front 66

Small Intestine

Back 66

Site where most of the body's digestion and absorption occurs.

Front 67

Smooth Endoplasmic Reticulum

Back 67

Does not have ribosomes attached, responsible for making lipids and breaking down toxic parts of the cell.

Front 68

Smooth Muscle

Back 68

Muscle tissue that contracts without conscious control, having the form of thin layers or sheets made up of spindle-shaped, unstriated cells with single nuclei and found in the walls of the internal organs, such as the stomach, intestine, bladder, and blood vessels, excluding the heart.

Front 69

Society

Back 69

An organization of individuals in a population in which tasks are divided, in order for a group to work together.

Example: Queen bee and worker bees.

Front 70

Somatic Sensory Nerves

Back 70

Controls all voluntary muscular systems within the body.

Front 71

Speciation

Back 71

The evolutionary formation of new biological species, usually by the division of a single species into two or more genetically distinct ones.

Front 72

Species

Back 72

A fundamental category of taxonomic classification, ranking below a genus or subgenus and consisting of related organisms capable of interbreeding.

Front 73

Sperm

Back 73

Male gamete or reproductive cell

Front 74

Sperm Nuclei

Back 74

One of the two nuclei in a pollen grain that function in double fertilization in seed plants.

Front 75

Spermatids

Back 75

Any of the four haploid cells formed by meiosis in a male organism that develop into spermatozoa without further division.

Front 76

Spermategenesis

Back 76

Formation and development of spermatozoa by meiosis and spermiogenesis.

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Spermatogonia

Back 77

An intermediary male gamet in the production of spermatozoa.

Front 78

Spinal Cord

Back 78

Continuation of the brain stem that serves as a conduit for motor and sensory information.

Front 79

Spindle Fibers

Back 79

Aggregates of microtubules that move chromosomes during cell division.

Form at opposite poles of a cell during prophase.

During metaphase, extend from the cell poles toward the midpoint of the cell known as the metaphase plate.

Chromosomes are held at the metaphase plate by the equal forces of the spindle fibers pushing on the centromeres of the chromosomes.

In anaphase, spindle fibers pull the chromatids toward the spindle poles. Spindle fibers not connected to chromatids lengthen and elongate the cell.

Front 80

Spleen

Back 80

Contains lymphatic tissue, and is located in the abdomen. It filters larger volumes of lymph than the nodes can handle.

Front 81

Spongy Layer

Back 81

A usually green, flattened, lateral structure attached to a stem and functioning as a principal organ of photosynthesis and transpiration in most plants.

Front 82

Sporophyte

Back 82

The spore-producing phase in the life cycle of a plant that exhibits alternation of generations.

Front 83

Starches

Back 83

Synthesized polysaccharides that plants use to store energy, most common plant fiber is known as cellulose.

Front 84

Stem

Back 84

Main support structure of the plant, produces leaves and lateral (parallel with the ground) branches.

Front 85

Steroid

Back 85

Any of numerous naturally occurring or synthetic fat-soluble organic compounds having as a basis 17 carbon atoms arranged in four rings and including the sterols and bile acids, adrenal and sex hormones, certain natural drugs such as digitalis compounds, and the precursors of certain vitamins.

Front 86

Stigma

Back 86

Sticky surface that at the top of the pistil, which traps pollen grains.

Front 87

Stimulus

Back 87

Something that causes and encourages a given response

Front 88

Stolens

Back 88

Above ground runners that grow roots of their own then develop into a new plant (strawberries).

Front 89

Stomach

Back 89

The enlarged, saclike portion of the alimentary canal, one of the principal organs of digestion, located in vertebrates between the esophagus and the small intestine.

Front 90

Stomata

Back 90

One of the minute pores in the epidermis of a leaf or stem through which gases and water vapor pass.

Front 91

Stroma

Back 91

The fluid in between grana, where carbohydrate formation reactions occur in the chloroplasts of plant cells photosynthesizing.

Front 92

Structural Genes

Back 92

Any gene that carries the genetic information for the structure of a protein.

Front 93

Style

Back 93

Slender vase-like structure that encloses the plant ovary.

Front 94

Substrate

Back 94

The material or substance on which an enzyme acts.

Front 95

Succession

Back 95

A gradual process incurred by the change in the number of individuals of each species of a community and by establishment of new species populations that may gradually replace the original inhabitants.

Front 96

Superclasses

Back 96

A taxonomic category of related organisms ranking below a phylum and above a class.

Front 97

Symbiosis

Back 97

When two species interact with each other within the same range.

Front 98

Sympathetic

Back 98

Part of the autonomic nervous system where the following can occur:


Fight or flight
Anxiety
Dilate pupils
Raise blood pressure
Raise heart rate
Stop digestion

Front 99

Sympatric Speciation

Back 99

The process through which new species evolve from a single ancestral species while inhabiting the same geographic region.

Front 100

Synapse

Back 100

Two homologous chromosomes lie very close to one another and become entwined. Occurs in Prophase 1 of meiosis.

Front 101

Synapses

Back 101

A structure that permits a neuron to pass an electrical or chemical signal to another cell.

Front 102

Range

Back 102

Total area occupied by a species.

Front 103

Reactants

Back 103

A substance participating in a chemical reaction, especially a directly reacting substance present at the initiation of the reaction.

Front 104

Receptor

Back 104

A cell or group of cells that respond to particular types of stimuli, enable the body to detect changes in the internal or external environment.

Front 105

Recessive

Back 105

Of, relating to, or designating an allele that does not produce a characteristic effect when present with a dominant allele.

Of or relating to a trait that is expressed only when the determining allele is present in the homozygous condition.

Front 106

Rectum

Back 106

Temporary storage site for feces.

Front 107

Reduction

Back 107

The first meiotic division, in which the chromosome number is reduced.

Front 108

Reflexes

Back 108

Auto movement of a body part in response to a stimulus.

Front 109

Regulatory Genes

Back 109

A gene that causes the production of a protein that regulates or suppresses the activity of one or more structural genes.

Front 110

Releaser

Back 110

A stimulus that releases a specific behavior pattern in an animal.

Front 111

Replacement Reaction

Back 111

One compound breaks apart and forms a new compound with a free reactant.

AB + C = AC + B

Front 112

Reptilia

Back 112

Snakes, lizards, alligators.

Front 113

RER

Back 113

Rough Endoplasmic Reticulum

Front 114

Respiratory System

Back 114

The integrated system of organs involved in the intake and exchange of oxygen and carbon dioxide between an organism and the environment.

Nose, mouth, lungs, bronchial tubes, trachea, diaphram.

Front 115

Restriction Enzymes

Back 115

Used to cut DNA into small strands of DNA for study.

Front 116

Rhizomes

Back 116

Horizontal underground plant stem capable of producing the upward shoot and downward root systems of a new plant. This capability allows vegetative (asexual) propagation and enables plants to survive an annual unfavourable season underground. (e.g., water lilies, many ferns, and forest herbs)

Front 117

Ribosomes

Back 117

Tiny particle, the site of protein synthesis, that is present in large numbers in living cells. They occur both as free particles within cells and, in eukaryotes, as particles attached to the membranes of the endoplasmic reticulum. They are 40% protein and 60% RNA. Ribosomes account for a large proportion of the total RNA of a cell. Proteins newly formed on ribosomes detach and migrate to other parts of the cell to be used.

Front 118

RNA

Back 118

A polymeric constituent of all living cells and many viruses, consisting of a long, usually single-stranded chain of alternating phosphate and ribose units with the bases adenine, guanine, cytosine, and uracil bonded to the ribose, involved in protein synthesis and sometimes in the transmission of genetic information. Also called ribonucleic acid.

Front 119

Robert Hooke

Back 119

Coined the term "cell"

Front 120

Root Cap

Back 120

Composed of dead, thick-walled cells. Covers the tip of th root, protecting it as the root pushes through the soil.

Front 121

Root Hairs

Back 121

The invisible hairs on tip ends of roots through which the plant absorbs water and dissolved nutrients.

Front 122

Rough Endoplasmic Reticulum

Back 122

Has attached ribosomes, in addition to transport of materials within the cell, it is also instrumental to protien synthesis.

Front 123

Ruminants

Back 123

Any of various hoofed, even-toed, usually horned mammals of the suborder Ruminantia, such as cattle, sheep, goats, deer, and giraffes, characteristically having a stomach divided into four compartments and chewing a cud consisting of regurgitated, partially digested food.

Front 124

Primary Spermatocytes

Back 124

A diploid cell that undergoes meiosis to form four spermatids. A primary spermatocyte divides into two secondary spermatocytes, which in turn divide to form the spermatids.

Front 125

Principles of Heredity

Back 125

1. Law of Segregation.
2. Law of Independant Assortment.
3. Law of Dominance

Front 126

Products

Back 126

A substance resulting from a chemical reaction.

Front 127

Prokaryotes

Back 127

No nucleus, or any membrane bound organelles, DNA usually forms a single chromosome which floats within the cytoplasm.

Include all bacteria.

Front 128

Properties of Cell Membranes

Back 128

Functions as a semi-permeable barrier, allowing a very few molecules across it while fencing the majority of organically produced chemicals inside the cell.

Electron microscopic examinations of cell membranes have led to the development of the lipid bilayer model (also referred to as the fluid-mosaic model). The most common molecule in the model is the phospholipid, which has a polar (hydrophilic) head and two nonpolar (hydrophobic) tails. These phospholipids are aligned tail to tail so the nonpolar areas form a hydrophobic region between the hydrophilic heads on the inner and outer surfaces of the membrane. This layering is termed a bilayer since an electron microscopic technique known as freeze-fracturing is able to split the bilayer.

Front 129

Properties of Water

Back 129

1. Excellent Solvent
2. High heat capacity
3. Ice Floats
4. Strong cohesion, high surface tension.
5. Strong adhesion.

Front 130

Prophase

Back 130

First phase of mitosis where the chromatin condense into chromosomes within the nucleus and becomes visible through a light microscope.

The nuclear membrane disolves and spindle fibers attache to the centromeres.

Front 131

Prosthetic Groups

Back 131

Facilitate enzyme reactions by bonding to the enzyme.

Front 132

Proteins

Back 132

Any of a group of complex organic macromolecules that contain carbon, hydrogen, oxygen, nitrogen, and usually sulfur and are composed of one or more chains of amino acids. Proteins are fundamental components of all living cells and include many substances, such as enzymes, hormones, and antibodies, that are necessary for the proper functioning of an organism. They are essential in the diet of animals for the growth and repair of tissue and can be obtained from foods such as meat, fish, eggs, milk, and legumes.

Front 133

Protons

Back 133

An elementary particle with a positive charge, found in the nucleus of an atom.


A proton is over a thousand times heavier than an electron.

Protons and neutrons make up most of an atom's mass.

Front 134

Punctuated Equilibrium

Back 134

A theory of social change which focuses on periods of continuity and relative stability (equilibrium) broken by phases of rapid change which upset the equilibrium. Thus such change need not be progressive or for the better in a purely developmental sense.

Front 135

Punnet Square

Back 135

A diagram that is used to predict an outcome of a particular cross or breeding experiment.

A summary of every possible combination of one maternal allele with one paternal allele for each gene being studied in the cross.

Front 136

Kidneys

Back 136

Either one of a pair of organs in the dorsal region of the vertebrate abdominal cavity, functioning to maintain proper water and electrolyte balance, regulate acid-base concentration, and filter the blood of metabolic wastes, which are then excreted as urine.

Front 137

Kin Selection

Back 137

Refers to apparent strategies in evolution that favor the reproductive success of an organism's relatives, even at a cost to the organism's own survival and reproduction (altruism).

Front 138

Kineses

Back 138

The activity of an organism in response to a stimulus; the direction of the response is not controlled by the direction of the stimulus.

Front 139

Kinetochore

Back 139

A specialized assembly of proteins that bind to the centromere and also attach to microtubules growing out from centrosomes during mitosis. They are involved in the separation of chromosomes into the daughter cells. They are composed of centromere-binding proteins.

Front 140

Kingdom

Back 140

Classifications for domain Eukaroyate.

Front 141

Kingdom Fungi

Back 141

mold, mushrooms, yeast, smuts, mildew.

Front 142

Kingdom Plantae

Back 142

Any of various photosynthetic, eukaryotic, multicellular organisms characteristically producing embryos, containing chloroplasts, having cellulose cell walls, and lacking the power of locomotion.

Front 143

Kingdom Protista

Back 143

Algea and Protozoa, usually unicelluar and most live in water.

Front 144

Kingdom Animalia

Back 144

Multicellular eukaryotic cells motile cells.

Worms, sponges, fish, insects, reptiles, amphibians, birds, mammals.

Front 145

Krebs Cycle

Back 145

Also called the citric acid cycle.

Front 146

Large Intestine

Back 146

The part of the gut between the small intestine and the anus: caecum, colon and rectum. ‘Large’ because it is a wider tube, although much shorter, than the ‘small’ intestine. From the caecum, low on the right side (from which the appendix arises), the ascending, then the transverse, then the descending parts of the colon lead to the rectum, low on the left side.

Water is progressively absorbed as the contents are moved onwards for storage in the rectum.

Front 147

Larynx

Back 147

Upper part of the trachea, also referred to as the wind pipe.

Front 148

Lateral Buds

Back 148

A bud borne in the axil of a leaf or branch; not terminal.

Front 149

Lateral Roots

Back 149

Extend horizontally from the primary root and serve to anchor the plant securely into the soil. This branching of roots also contributes to water uptake, and facilitates the extraction of nutrients required for the growth and development of the plant.

Front 150

Law of Dominance

Back 150

Mendel determined that one gene usually expressed itself over the gene.

Front 151

Law of Independant Assortment

Back 151

The principles that govern heredity were discovered by a monk named Gregor Mendel in the 1860's. One of these principles, states that allele pairs separate independently during the formation of gametes. This means that traits are transmitted to offspring independently.

Front 152

Law of Segregation

Back 152

Any individual produces gametes, the copies of a gene separate so that each gamete receives only one copy (allele). A gamete will receive one allele or the other. The direct proof of this was later found following the observation of meiosis by two independent scientists, the German botanist, Oscar Hertwig in 1876, and the Belgian zoologist, Edouard Van Beneden in 1883. In meiosis, the paternal and maternal chromosomes get separated and the alleles with the traits of a character are segregated into two different gametes.

Front 153

Laws of Thermodynamics

Back 153

Matter and energy can neither be created nor destroyed.

All reactions spread energy which ends to diminish its availibility.

Front 154

Leaf

Back 154

A usually green, flattened, lateral structure attached to a stem and functioning as a principal organ of photosynthesis and transpiration in most plants.

Front 155

Learned Behavoirs

Back 155

Opposite of innate behavoirs.

Front 156

Life History Strategies

Back 156

Opportunistic (R Selected).

Equilibreal (K Selectect).

Front 157

Lightening

Back 157

Can be used for nitrogen fixing.

Front 158

Limiting Factors

Back 158

Controls a population's growth, such as organism growth or species population, size, or distribution. Includes space, water, and food. The availability of food, predation pressure, or availability of shelter are examples of factors that could be limiting for an organism. An example of a limiting factor is sunlight in the rainforest, where growth is limited to all plants in the understory unless more light becomes available.

Front 159

Linkage

Back 159

The association of genes having located on the same chromosome, which results in the tendency of a group of such nonallelic genes to be associated in inheritance.

Front 160

Lipids

Back 160

Hydrophobic (water-fearing) and will not disolve in water. Their main biological function is to store energy.

Examples: Waxes, Steroids, Phospholipids, and fats.

Front 161

Lithosphere

Back 161

Ground

Front 162

Liver

Back 162

Largest organ inside the body. Changes food into energy and cleaning alcohol and poisons the blood and makes bile, a yellowish-green liquid that helps with digestion.

Front 163

Locus

Back 163

The chromosomal position of a gene as determined by its linear order relative to the other genes on that chromosome.

Front 164

Lungs

Back 164

Either of two spongy, saclike respiratory organs in most vertebrates, occupying the chest cavity together with the heart and functioning to remove carbon dioxide from the blood and provide it with oxygen.

Front 165

Lymph

Back 165

A clear, watery, sometimes faintly yellowish fluid derived from body tissues that contains white blood cells and circulates throughout the lymphatic system, returning to the venous bloodstream through the thoracic duct. Acts to remove bacteria and certain proteins from the tissues, transport fat from the small intestine, and supply mature lymphocytes to the blood.

Front 166

Lymph Nodes

Back 166

Small, rounded structures along the small vessels of the lymphatic system that produce disease-fighting white blood cells and filter out harmful microorganisms and toxins from the lymph. They may become enlarged when they are actively fighting infection.

Front 167

Lymphatic System

Back 167

Composed of lymph, lymph nodes, spleen, thymus, and tonsils.

Front 168

Lymphocytes

Back 168

Any of the nearly colorless cells found in the blood, lymph, and lymphoid tissues, constituting approximately 25 percent of white blood cells and including B cells, which function in humoral immunity, and T cells, which function in cellular immunity.

Front 169

Lysosomes

Back 169

Membrane bound organelles containing enzymes to digest unused material or damaged organelles.

Front 170

Male Gamete

Back 170

Sperm

Front 171

Mammalia

Back 171

Hair, four chambered heart, highly developed brain, internal fertilization, milk producing.

Cows, humans, apes, ect.

Front 172

Maturation Region

Back 172

Above the elongation region where cells differentiate into various root tissue.

Front 173

Medulla Oblongata

Back 173

Controls involuntary response such as breathing at heartbeat.

Front 174

Meiosis

Back 174

Process that produces four daughter haploid cells.

Front 175

Meristem

Back 175

Undifferientiated cells capable of quick growth and specialization, the region where elongation of the stem occurs.

Front 176

Meristematic Region

Back 176

Just above the root cap. Consists of undifferentiated cells which carry on mitosis, producing cells that grow to form elongation region.

Front 177

Mesoderm

Back 177

The middle embryonic germ layer, lying between the ectoderm and the endoderm, from which connective tissue, muscle, bone, and the urogenital and circulatory systems develop.

Front 178

Metaphase

Back 178

The stage of mitosis and meiosis, following prophase and preceding anaphase, during which the chromosomes are aligned along the metaphase plate.

Front 179

Microfilaments

Back 179

Thinnest part of the cytoskeleton

Front 180

Microtubules

Back 180

Long, hollow, cylindrical protien filaments which give structure to the cell.

Front 181

Microvilli

Back 181

Projections of the cell extending from the cell membrane. They increase the surface are of the cel membrane, increasing the area available to absorb nutrients, they also contain enzymes involved in digesting certain types of nutrients.

Front 182

Midbrain

Back 182

Portion of the central nervous system associated with vision, hearing, motor control, sleep/wake, arousal (alertness), and temperature regulation.

Front 183

Migration

Back 183

Temporary movement out of one range into another, and back.

Front 184

Minimal Viable Population

Back 184

When a population is signifigantly diminished in size it becomes highly susceptible to breeding problems.

Front 185

Mitochondria

Back 185

A spherical or elongated organelle in the cytoplasm of nearly all eukaryotic cells, containing genetic material and many enzymes important for cell metabolism, including those responsible for the conversion of food to usable energy.

Front 186

Mitosis

Back 186

The process in cell division by which the nucleus divides, typically consisting of four stages, prophase, metaphase, anaphase, and telophase, and normally resulting in two new nuclei, each of which contains a complete copy of the parental chromosomes.

Front 187

Mobile Receptor Mechanism

Back 187

Applies to steroid hormones.

Front 188

Modern Synthesis

Back 188

Darwinism as modified by the findings of modern genetics

Front 189

Molecule

Back 189

Two more atoms held together by a bond.

Front 190

Mollusca

Back 190

Snails, clams, squid.

Front 191

Monocots

Back 191

Parelle leaf veins, stems have random arrangement of vascular bundles, fibrous root, flowers with petals in mutiples of three.

Examples: Grasses, Lilies, Palm Trees.

Front 192

Monohybrid Cross

Back 192

Cross between two individuals where only one trait is considered.

Front 193

Monomers

Back 193

A molecule that can combine with others to form a polymer.

Front 194

Monosaccharide

Back 194

A simple sugar, example: fructose, glucose, and ribose.

The simplest form of carbohydrate; therefore, it cannot be broken down to simpler sugars by hydrolysis.

Front 195

Mortality

Back 195

Death rate.

Front 196

Morula

Back 196

The spherical embryonic mass of blastomeres formed before the blastula and resulting from cleavage of the fertilized egg.

Front 197

Motor Division

Back 197

The motor division of the PNS is subdivided into several branches. The somatic motor branch carries voluntary (willed) commands to the skeletal muscles, allowing a person to perform such action as swatting a mosquito or sticking out the tongue. The autonomic motor branch carries autonomic (automatic, or unwilled) commands to a variety of muscles and glands throughout the body, allowing the brain to control heart rate, blood pressure, breathing rate, sweat production, and hormone release, among other functions.

Front 198

Mouth

Back 198

Oral cavity, is the organ in injestion and the first organ of digestion in the G1 tract.

Front 199

mRNA

Back 199

Messenger RNA, migrates from the nucleus into the cytoplasm.

Front 200

Multiple Alleles

Back 200

Any of a set of three or more alleles, or alternative states of a gene, only two of which can be present in a diploid organism.

Common Example: Blood.

Front 201

Multiple Fruit

Back 201

Fruits that are formed from a cluster of flowers. Each flower in the inflorescence produces a fruit, but these mature into a single mass.

Example: Pineapple.

Front 202

Muscle Tissue

Back 202

Smooth, cardiac, skeletal.

Front 203

Musculoskeletal System

Back 203

Provides the body with structure, stability, and the ability to move.

Front 204

Mutation

Back 204

A change of the DNA sequence within a gene or chromosome of an organism resulting in the creation of a new character or trait not found in the parental type.

Front 205

Mutualism

Back 205

Form of symbiosis where both species benefit.

Front 206

Myelin Sheath

Back 206

The insulating envelope of myelin that surrounds the core of a nerve fiber or axon and facilitates the transmission of nerve impulses. In the peripheral nervous system, the sheath is formed from the cell membrane of the Schwann cell and, in the central nervous system, from oligodendrocytes.

Front 207

Nasal Passages

Back 207

Air passing through the nasal cavity is warmed or cooled to within 1 degree of body temperature. In addition, the air is humidified, and dust and other particulate matter is removed by vibrissae, short, thick hairs, present in the vestibule.

Front 208

Natality

Back 208

Birth rate.

Front 209

Native

Back 209

An animal or plant that originated in a particular place or region.

Front 210

Natural Selection

Back 210

The process in nature by which, according to Darwin's theory of evolution, only the organisms best adapted to their environment tend to survive and transmit their genetic characteristics in increasing numbers to succeeding generations while those less adapted tend to be eliminated.

Front 211

Nematoda

Back 211

Round worms.

Front 212

Nerve Tissue

Back 212

Found in the brain, spinal cord and ganglion. Carries electrical and chemical impulese to and from organs and limbs to the brain.

Front 213

Nervous System

Back 213

A communication network that connects the entire body of an organism and provides control over bodily functions and actions

Front 214

Neurons

Back 214

Any of the impulse-conducting cells that constitute the brain, spinal column, and nerves, consisting of a nucleated cell body with one or more dendrites and a single axon. Also called nerve cell.

Front 215

Neutrons

Back 215

An elementary particle without an electrical charge; one of the building blocks of the nucleus of the atom. A neutron has about the same mass as a proton.

Front 216

Niche

Back 216

The role a species plays in the enviroment. Includes physical requirements and biological activities.

Front 217

Nitrates

Back 217

Nitrates are important to all living systems. Plants, especially, require it to develop and produce seeds. Nitrogen, the main component of Earth's atmosphere, is a relatively inert substance. To be useful, it must be converted into active forms. Lightning and radiation create nitrates in the atmosphere, where rainstorms carry them to the ground. Bacteria on roots of crops such as alfalfa and clover fix nitrogen in the soil. Microorganisms form nitrates as they break down animal matter.

Front 218

Nitrification

Back 218

Chemical process in which nitrogen (mostly in the form of ammonia) in plant and animal wastes and dead remains is oxidized at first to nitrites and then to nitrates. These reactions are effected mainly by the bacteria Nitrosomonas and Nitrobacter respectively. Unlike ammonia, nitrates are readily taken up by plant roots; nitrification is therefore a crucial part of the nitrogen cycle. Nitrogen-containing compounds are often applied to soils deficient in this element, as fertilizer.

Front 219

Nitrogen Cycle

Back 219

The circulation of nitrogen in nature, consisting of a cycle of chemical reactions in which atmospheric nitrogen is compounded, dissolved in rain, and deposited in the soil, where it is assimilated and metabolized by bacteria and plants, eventually returning to the atmosphere by bacterial decomposition of organic matter.

Front 220

Nitrogen Fixing

Back 220

The conversion of atmospheric nitrogen (which plants cannot absorb) into forms of nitrogen that plants can absorb. Bacteria in the topsoil carry out the conversion.

Front 221

Nitrogen Fixing Bacteria

Back 221

Fix atmospheric nitrogen gas into a more usable form such as ammonia.

Front 222

Nodes

Back 222

Location along the stem where new leaves sprout.

Front 223

Nonvascular Plants

Back 223

Bryophytes, cannot conduct food or water, as a result are generally only a few centimeters tall.

Front 224

Nuclear Membrane

Back 224

Is a double lipid bilayer that encloses the genetic material in eukaryotic cells.

Front 225

Nuclear Pores

Back 225

An octagonal opening where the inner and outer membranes of the nuclear envelope are continuous.

Front 226

Nucleic Acids

Back 226

DNA -- Deoxyribonucleic Acid

RNA -- Ribonucleic Acid

Front 227

Nucleolus

Back 227

A small, typically round granular body composed of protein and RNA in the nucleus of a cell. It is usually associated with a specific chromosomal site and involved in ribosomal RNA synthesis and the formation of ribosomes.

Front 228

Nucleosomes

Back 228

Any of the repeating subunits of chromatin, consisting of a DNA chain coiled around a core of histones.

Front 229

Nucleotides

Back 229

Building blocks of deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). Individual nucleotide monomers (single units) are linked together to form polymers, or long chains. DNA chains store genetic information, while RNA chains perform a variety of roles integral to protein synthesis. Individual nucleotides also play important roles in cell metabolism.

Front 230

Nucleus

Back 230

Specialized structure occurring in most cells (except bacteria) and separated from the rest of the cell by the nuclear membrane. This membrane seems to be continuous with the cell's endoplasmic reticulum and has pores that permits the passage of large molecules. The nucleus controls and regulates the cell's activities (e.g., growth and metabolism) and carries the genes. Nucleoli are small bodies often seen within the nucleus that play an important part in the synthesis of RNA and protein. A cell normally contains only one nucleus.

Front 231

Olfactory Lobes

Back 231

Sense smell.

Front 232

Omnivores

Back 232

Animals that consume both plants and other animals.

Front 233

Oparian Hypothesis

Back 233

In the 1930s, a Russian scientist, Alexander Oparin, hypothesized that life began in the oceans on early earth between 3.9 to 3.5 billion years ago. He suggested that first, simple organic molecules containing carbon formed. Energy from the sun, lightning, and earth's heat triggered chemical reactions to produce small organic molecules from substances present in the atmosphere. These molecules were organized by chance into complex organic molecules such as proteins, carbohydrates, and nucleic acids that are essential to life.

Front 234

Open Circulatory System

Back 234

Blood directly bathes the internal organs.

Front 235

Open Community

Back 235

A community which other organisms readily colonize because some niches are unoccupied.

Front 236

Opportunistic

Back 236

R selected.

Short maturation times, short life spans, high morality rates, high numbers of offspring, do not parent their young.

Front 237

Optic Lobes

Back 237

Either of two lobes of the dorsal part of the midbrain, containing primary visual centers.

Front 238

Orbital

Back 238

Electron shell.

Front 239

Organelles

Back 239

Specialized subunit within a cell that has a specific function.

Front 240

Organic Cofactors

Back 240

Coenzymes (usually vitamins).

Front 241

Organic Compounds

Back 241

Contain Carbon.

Front 242

Organism

Back 242

An individual form of life, such as a plant, animal, bacterium, protist, or fungus; a body made up of organs, organelles, or other parts that work together to carry on the various processes of life.

Front 243

Osmosis

Back 243

Spontaneous passage or diffusion of water or other solvent through a semipermeable membrane. If a solution is separated from a pure solvent by a membrane that is permeable to the solvent but not to the solute, the solution will tend to become more dilute by absorbing solvent through the membrane.

Front 244

Osteichthyes

Back 244

Fish with a bony skeleton, numerous vertabraw, swim bladder, two-chambered heart, gills with bony gill arches, and external fertilization.

Examples: Tuna, Carp, Herring

Front 245

Ovary

Back 245

The ovule-bearing lower part of a pistil that ripens into a fruit.

Front 246

Ovules

Back 246

A minute structure in seed plants, containing the embryo sac and surrounded by the nucellus, that develops into a seed after fertilization.

Front 247

Primary Roots

Back 247

Extend downward.

Front 248

Primary Oocytes

Back 248

Present in great number of females in the ovaries at birth. Undergo meosis 1 forming one polar body and one secondary oocyte.

Front 249

Predator

Back 249

An organism that eats another.

Front 250

Post Transcriptional Processing

Back 250

Occurs in the cytoplasm after transcription, and prepates the mRNA for protein sythesis by removing the non-coding sequences.

Front 251

Porifera

Back 251

Phylum under Kingdom Animalia that contains sponges.

Front 252

Population

Back 252

Total number of a single species of organism found in a given ecosystem.

Front 253

Polysaccharide

Back 253

Any of a class of carbohydrates, such as starch and cellulose, consisting of a number of monosaccharides joined by glycosidic bonds.

Front 254

Polypeptides

Back 254

A polymer of amino acids joined together by peptide bonds

Front 255

Polymers

Back 255

Molecules which consist of a long, repeating chain of smaller units called monomers. Polymers have the highest molecular weight among any molecules, and may consist of billions of atoms. Human DNA is a polymer with over 20 billion constituent atoms. Proteins, or the polymers of amino acids, and many other molecules that make up life are polymers. Polymers are the largest and most diverse class of known molecules. They even include plastics.

Front 256

Polygenetic Traits

Back 256

Ss a distinguishing characteristic or quality for which the phenotype (appearance) depends on alleles in multiple genes.

Front 257

Polygenetic Inheritance

Back 257

Inheritance in which more than one gene pair affects the appearance of a particular trait.

Front 258

Pollen Tube

Back 258

The slender tube formed by the pollen grain that penetrates an ovule and releases the male gametes.

Front 259

Pollen Grains

Back 259

A microspore of seed plants, containing a male gametophyte.

Front 260

Polar Molecules

Back 260

Partial negative charge on one region, partial positive charge on the another region.

Front 261

Polar Body

Back 261

Either of the two small cells that form as a result of meiosis of a primary oocyte during its development to a mature ovum. One is formed in the first division, and the other in the second division. At each division, the cytoplasm divides unequally, the polar body being much smaller than the developing oocyte. At the second division the polar body and the developing oocyte each contains a haploid set of chromosomes. The polar bodies eventually degenerate.

Front 262

Ploidy

Back 262

The number of single sets of chromosomes in a cell or an organism.

Haploid is having the same number of sets of chromosomes as a germ cell or half as many as a somatic cell.

Diploid is having two sets or a pair of chromosomes, as normally found in the somatic cell of higher organisms. A diploid cell has one chromosome from each parent.

Front 263

Platyhelminthes

Back 263

A phylum of invertebrates composed of bilaterally symmetrical, nonsegmented, dorsoventrally flattened worms characterized by lack of coelom, anus, circulatory and respiratory systems, and skeleton.

Front 264

Plants

Back 264

Organsims that produce their own food through the process of photosynthesis.

Front 265

Plant Hormones

Back 265

Giberellins: Cell division and elongatio.
Cytokins : Cell division and fruit development.
Abscicis acid: Opening and closing of the stomate, controlling water lost through transpiration and formation of winter buds that put plain in dormant state)
Ethylene: Ripening of fuite (spoiling releases ethylene which stimulates ripening of surrounding fruit.
Auxis: Growth Factors.

Front 266

Plant Cells

Back 266

Chloroplasts, Cytoplasm, Endoplasmic reticulum, ribosomes, mitochondria, large central vacuole, plastids, golgi apparatus, cell wall, microtubules, microfilaments, nucleus, rectangular in shape.

Front 267

Placenta

Back 267

A membranous vascular organ that develops in female mammals during pregnancy, lining the uterine wall and partially enveloping the fetus, to which it is attached by the umbilical cord. Following birth, the placenta is expelled.

Nutrients, water and oxygen diffuse from the mother's blood into the embyo's, while wastes and carbon dioxide diffuse into the mother's blood supply.

Front 268

Pituitary Gland

Back 268

A small oval endocrine gland attached to the base of the vertebrate brain and consisting of an anterior and a posterior lobe, the secretions of which control the other endocrine glands and influence growth, metabolism, and maturation. Also called hypophysis, pituitary body.

Front 269

Pistil

Back 269

Female part of a flower that includes the style, stigma, ovary and ovules.

Front 270

Pioneer Communities

Back 270

The first population to adapt to a ecosytem. Tend to be hardy and can survive in bleak conditions.

Front 271

Phylum

Back 271

A primary division of a kingdom, as of the animal kingdom, ranking next above a class in size.

Front 272

Phylogenetic Tree

Back 272

A branching diagram or "tree" showing the inferred evolutionary relationships among various biological species or other entities based upon similarities and differences in their physical and/or genetic characteristics.

The taxa joined together in the tree are implied to have descended from a common ancestor.

Front 273

Phototrophic

Back 273

An organism that obtains energy from sunlight for the synthesis of organic compounds.

Front 274

Photosynthesis

Back 274

The process in green plants and certain other organisms by which carbohydrates are synthesized from carbon dioxide and water using light as an energy source. Most forms of photosynthesis release oxygen as a byproduct.

Front 275

P1 Generation

Back 275

Parent or first generation.

Front 276

Palisade Layer

Back 276

Found within the mesophyll, contain chloroplasts, most photosynthesis occurs in this layer.

Front 277

Pancreas

Back 277

Part of the digestive system that is both an endocrine gland producing several important hormones, including insulin, glucagon, and somatostatin, and a digestive organ, secreting pancreatic juice containing digestive enzymes that assist the absorption of nutrients and the digestion in the small intestine. These enzymes help to further break down the carbohydrates, proteins, and lipids in the chyme.

Front 278

Parasitism

Back 278

Symbiosis in whice on species benefits, but the other is harmed.

Front 279

Parasympathetic

Back 279

Part of the autonomic nervous system where the following occurs:

Feed & breed Regulate
Rest & digest digestion
Constrict pupils
Lower blood pressure
Lower heart rate
Digestion can occur

Front 280

Parenchyma

Back 280

The basic tissue of plants, consisting of cells with thin cellulose walls. The cortex and pith of the stem, the internal layers of leaves, and the soft parts of fruits are made of parenchyma. In contrast to sclerenchyma cells, parenchyma cells remain alive at maturity. They perform various functions, such as water storage, replacement of damaged tissue, and physical support of plant structures. Chloroplasts, the organelles in which photosynthesis takes place, are found in parenchyma cells.

Front 281

Passive Transport

Back 281

Moving substances across membranes without energy. Dependent on the permeability of the cell membrane, which, in turn, is dependent on the organization and characteristics of the membrane lipids and proteins.

Four main kinds are diffusion, facilitated diffusion, filtration and osmosis.

Front 282

Pedicel

Back 282

A stem that attaches single flowers to the main stem .

Front 283

Perennial

Back 283

A plant that lives for more than two years.

Front 284

Periodic Table of Elements

Back 284

A tabular arrangement of the elements according to their atomic numbers so that elements with similar properties are in the same column.

Front 285

Periphial Nervous System

Back 285

Consists of the nerves and ganglia outside
of the brain and spinal cord (CNS).

Front 286

Petals

Back 286

Brightly colored to attract insects and birds, which may be necessary to the process of pollination.

Front 287

PH

Back 287

A measure of the acidity or alkalinity of a solution, numerically equal to 7 for neutral solutions, increasing with increasing alkalinity and decreasing with increasing acidity. The pH scale commonly in use ranges from 0 to 14.

Front 288

Pharynx

Back 288

Canal that extends from the mouth and nasal cavities to the larynx, where it becomes continuous with the esophagus.

Front 289

Phenotype

Back 289

The observable physical or biochemical characteristics of an organism, as determined by both genetic makeup and environmental influences.

Front 290

Phosphorous Cycle

Back 290

Initially, phosphate weathers from rocks. The small losses in a terrestrial system caused by leaching through the action of rain are balanced in the gains from weathering rocks. In soil, phosphate is absorbed on clay surfaces and organic matter particles and becomes incorporated (immobilized). Plants dissolve ionized forms of phosphate. Herbivores obtain phosphorus by eating plants, and carnivores by eating herbivores. Herbivores and carnivores excrete phosphorus as a waste product in urine and feces. Phosphorus is released back to the soil when plants or animal matter decomposes and the cycle repeats.

Front 291

Photolysis

Back 291

Light reaction in photosynthesis.

Front 292

Photoperiodcity

Back 292

Affects growth or reproduction, of an organism to the length of exposure to light in a 24-hour period

Front 293

Immigration

Back 293

Permanent one way movement into a new range.

Front 294

Immune System

Back 294

Functions to defend the body from infection by bacteria and viruses.

Front 295

Imprinting

Back 295

Form of learning wherein a very young animal fixes its attention on the first object with which it has visual, auditory, or tactile experience and thereafter follows that object. In nature, the object is almost always a parent; in experiments, other animals and inanimate objects have been used.

Front 296

Incomplete Dominance

Back 296

A heterozygous condition in which both alleles at a gene locus are partially expressed and which often produces an intermediate phenotype.

Example: One red, and one white flower = Pink.

Front 297

Ingestion

Back 297

To take into the body by the mouth for digestion or absorption.

Front 298

Inheritance

Back 298

Process by which characteristics pass from one generation to another.

Front 299

Inhibitor

Back 299

To decrease, limit, or block the action or function of an enzyme.

Front 300

Innate Behaviors

Back 300

Instincts

Front 301

Inorganic Cofactors

Back 301

Iron, copper, zinc.

Front 302

Instincts

Back 302

An inborn pattern of behavior that is characteristic of a species and is often a response to specific environmental stimuli.

Front 303

Internode

Back 303

A section or part between two nodes, as of a nerve or stem.

Front 304

Interphase

Back 304

The period when the cell is active and carrying on its normal function.

Front 305

Invertabrates

Back 305

Species that have no internal backbone.

Examples: Sponges, worms, molusks, crustaceans.

Front 306

Ionic Bond

Back 306

A chemical bond in which one atom gives up an electron to another, thereby generating an electrical force that holds the atoms together.

These type of bonds are weaker than a covalent bond.

Front 307

Ions

Back 307

An atom that has either lost or gained one or more electron. A positive ion remains if an electron is removed, for example, by being struck by a photon or fast charged particle of sufficient energy to overcome the binding energy of that electron.

Front 308

Habitat

Back 308

The area or environment where an organism or ecological community normally lives

Front 309

Habituation

Back 309

Reduction of an animal's behavioral response to a stimulus, as a result of a lack of reinforcement during continual exposure to the stimulus. Habituation is usually considered a form of learning in which behaviours not needed are eliminated. It may be separated from most other forms of decreased response on the basis of permanence; the habituated animal either does not resume its earlier reaction to the stimulus after a period of no stimulus, or, if the normal reaction is resumed on reexposure to the stimulus, it wanes more quickly than before. Vital responses (e.g., flight from a predator) cannot be truly habituated.

Front 310

Haploid

Back 310

Describing a cell, an organism or a nucleus of a cell having a single genome or a single set of homologous chromosomes; i.e. containing half the diploid number; having a ploidy of one.

Front 311

Hardy-Weinberg Law of Equilibrium

Back 311

p2 + 2pq + q2 = 1 and p + q = 1

No mutations must occur so that new alleles do not enter the population.
No gene flow can occur (i.e. no migration of individuals into, or out of, the population).
Random mating must occur (i.e. individuals must pair by chance)
The population must be large so that no genetic drift (random chance) can cause the allele frequencies to change.
No selection can occur so that certain alleles are not selected for, or against.

Front 312

Heart

Back 312

The chambered muscular organ in vertebrates that pumps blood received from the veins into the arteries, thereby maintaining the flow of blood through the entire circulatory system.

Front 313

Heme

Back 313

Iron

Front 314

Hemoglobin

Back 314

Contained within the red blood cells, giving blood its characteristic color.

It serves to transport oxygen from the lungs to the tissues.

Front 315

Heterozygous

Back 315

Having different alleles at one or more corresponding chromosomal loci.

(Yy)

Front 316

Hindbrain

Back 316

Includes the medulla (controls involuntary response such as bearthing and heartbeat), pons, and cerebellum (controls balance and equilibrium).

Front 317

Histones

Back 317

Any of several small, basic proteins most commonly found in association with the DNA in the chromatin of eukaryotes.

Front 318

History of Evolutionary Concepts

Back 318

Linnaues --> Darwin --> Modern Concept (genetics)

Front 319

Home Range

Back 319

The geographic area to which an organism normally confines its activity.

Front 320

Homeostasis

Back 320

The ability or tendency of an organism or cell to maintain internal equilibrium by adjusting its physiological processes.

Front 321

Homologuos

Back 321

Similar in structure and evolutionary origin, though not necessarily in function, as the flippers of a seal and the hands of a human.

Front 322

Homologuos Chromosomes

Back 322

Chromosome pairs of approximately the same length, centromere position, and staining pattern, with genes for the same characteristics at corresponding loci. One homologous chromosome is inherited from the organism's mother; the other from the organism's father They are usually not identical.

Front 323

Homologs

Back 323

A pair of chromosomes, one inherited from each parent, that have corresponding gene sequences and that pair during meiosis.

Front 324

Homozygous

Back 324

Having the same alleles at a particular gene locus on homologous chromosomes.

(YY or yy)

Front 325

Hormone-Receptor Complex

Back 325

A hormone receptor is a protein complex through which hormones interact with cells. Hormones use their receptors to regulate whether a protein is produced or not, and to control the amount of a protein that is made. Some receptors are located in the cell membrane and interact with genes indirectly through chemical signals, while others are near the nucleus and control the expression of DNA directly. Inside the cell, a hormone receptor is activated by forming a complex with a steroid molecule.

Front 326

Hormones

Back 326

Any of various similar substances found in plants and insects that regulate development.

A substance, usually a peptide or steroid, produced by one tissue and conveyed by the bloodstream to another to effect physiological activity, such as growth or metabolism.

Front 327

Hydrogen Bond

Back 327

A weak chemical bond between water molecules.

Front 328

Hydrologic Cycle

Back 328

The cycle of evaporation and condensation that controls the distribution of the earth's water as it evaporates from bodies of water, condenses, precipitates, and returns to those bodies of water.

Front 329

Hydrosphere

Back 329

The portion of Earth, or other planet, that is water, including liquid water, ice, and water vapor on the surface, underground, or in the atmosphere.

Front 330

Hypothalamus

Back 330

Part of the brain that controls hunger, thirst, blood pressure, body temperature, hostility, pain, pleasure ect...

Front 331

F1 Generation

Back 331

First generation of offspring.

Front 332

F2 Generation

Back 332

Second generation of offspring. (Offspring from F1 generation)

Front 333

Facilitated Diffusion

Back 333

Does not require energy, but it cannot occur without the help of specialized proteins.

Front 334

Family

Back 334

Ranking of taxonomy fitting between order and genus.

Front 335

Fats

Back 335

Highly efficient lipid molecules used for long term energy storage. When an organism takes in more carbohydrates than are necessary for its energy use, the excess energy storage is stored in fat molecules.

Front 336

Feces

Back 336

Waste matter eliminated from the bowels; excrement.

Front 337

Feedback Control

Back 337

Helps acheive homeostasis.

Front 338

Feedback Response

Back 338

Reaction to a feedback control stimulus.

Front 339

Female Gamete

Back 339

Egg cell.

Front 340

Fermentation

Back 340

The anaerobic conversion of sugar to carbon dioxide and alcohol by yeast.

Front 341

Fertilization

Back 341

The union of male and female gametes to form a zygote.

Front 342

Filament

Back 342

The stalk that bears the anther in a stamen.

Front 343

Fixed Action Patterns

Back 343

An innate behavior that appears to be substantially complete the first time the organism encounters the relevant stimulus.

Front 344

Flower

Back 344

Primary reproductive organ of an angiosperm.

Front 345

Food Chain

Back 345

The chain between green plants (the primary producers of food energy) through a sequence of organisms in which each eats the one below it in the chain, and is eaten in turn by the one above.

Front 346

Food Web

Back 346

Whereas a food chain is a linear series of organisms dependent on each other for food, a food web is an interconnected set of food chains in the same ecosystem.

Front 347

Forebrain

Back 347

Largest part of the brain, contains olfactory lobes (sense smell), cerebrum (controls sensory and motor responses, memory, speech and most factors of intelligence), thalamus (integrates senses), hypothalamus (hunger, thirst, blood pressure, body temperature, pain, pleasure, hostility) and the pituitary gland(releases hormones).

Front 348

Fossil Fuels

Back 348

Any of a class of materials of biologic origin occurring within the Earth's crust that can be used as a source of energy. Fossil fuels include coal, petroleum, and natural gas. They all contain carbon and were formed as a result of geologic processes acting on the remains of (mostly) plants and animals that lived and died hundreds of millions of years ago. All fossil fuels can be burned to provide heat, which may be used directly, as in home heating, or to produce steam to drive a generator for the production of electricity. Fossil fuels supply nearly 90% of all the energy used by industrially developed nations.

Front 349

Fourth & Fifth Trophic Levels

Back 349

Carnivores or apex predators.

Front 350

Free Ribosomes

Back 350

A ribosome located by itself or in a group (known as a polysome or polyribosome) in the cytosol, rather than bound to the endoplasmic reticulum; synthesizes soluble cytosolic proteins and most extrinsic membrane proteins.

Front 351

Fruit

Back 351

The ripened ovary or ovaries of a seed-bearing plant, together with accessory parts, containing the seeds and occurring in a wide variety of forms.

Front 352

G1 Phase

Back 352

First phase of interphase, most of the cell growth occurs at this time.

Front 353

G2 Phase

Back 353

Final phase of interphase, protiens are produced to assist with cell division.

Front 354

Gall Bladder

Back 354

A small, pear-shaped muscular sac, located under the right lobe of the liver, in which bile secreted by the liver is stored until needed by the body for digestion.

Front 355

Gametes

Back 355

A reproductive cell having the haploid number of chromosomes, especially a mature sperm or egg capable of fusing with a gamete of the opposite sex to produce the fertilized egg.

Front 356

Gametogenesis

Back 356

The formation or production of gametes.

Front 357

Gametophytes

Back 357

The gamete-producing phase in a plant characterized by alternation of generations.

Front 358

Gas Exchange System

Back 358

Also known as the respiratory system, responsible for the intake and processing of gases required by an organism and expelling gases produced as waste products.

Front 359

Gastrointestinal Tract

Back 359

The human gastrointestinal tract refers to the stomach and intestine, and sometimes to all the structures from the mouth to the anus.

Front 360

Gastrula

Back 360

An embryo at the stage following the blastula, consisting of a hollow, two-layered sac of ectoderm and endoderm surrounding an archenteron that communicates with the exterior through the blastopore.

Front 361

Gastrulation

Back 361

A phase early in the embryonic development of most animals, during which the single-layered blastula is reorganized into a trilaminar ("three-layered") structure known as the gastrula. These three germ layers are known as the ectoderm, mesoderm, and endoderm.

Front 362

Gene

Back 362

A hereditary unit consisting of a sequence of DNA that occupies a specific location on a chromosome and determines a particular characteristic in an organism.

Front 363

Gene Migration

Back 363

Migration into or out of a population may be responsible for a marked change in allele frequencies (the proportion of members carrying a particular variant of a gene). Immigration may also result in the addition of new genetic variants to the established gene pool of a particular species or population.

Front 364

Gene Pool

Back 364

The entire collection of genes within a given population.

Front 365

Genetic Drift

Back 365

Change in the pool of genes of a small population that takes place strictly by chance. Genetic drift can result in genetic traits being lost from a population or becoming widespread in a population without respect to the survival or reproductive value of the gene pairs (alleles) involved. A random statistical effect, genetic drift can occur only in small, isolated populations in which the gene pool is small enough that chance events can change its makeup substantially. In larger populations, any specific allele is carried by so many individuals that it is almost certain to be transmitted by some of them unless it is biologically unfavourable.

Front 366

Genetic Engineering

Back 366

Direct human manipulation of an organism's genome using modern DNA technology. It involves the introduction of foreign DNA or synthetic genes into the organism of interest. The introduction of new DNA does not require the use of classical genetic methods, however traditional breeding methods are typically used for the propagation of recombinant organisms.

Front 367

Genomes

Back 367

The sum total of genetic information of an organism.

Front 368

Genotype

Back 368

The genetic makeup of a cell, an organism, or an individual (i.e. the specific allele makeup of the individual) usually with reference to a specific character under consideration.

Example: Bb

Front 369

Genus

Back 369

Subdivision of a family or subfamily in the classification of organisms, usually consisting of more than one species.

Front 370

Geotropic

Back 370

The growth of a living organism in response to gravity, as the downward growth of plant roots.

Front 371

Germ Layers

Back 371

Any of three cellular layers, the ectoderm, endoderm, or mesoderm, into which most animal embryos differentiate and from which the organs and tissues of the body develop through further differentiation.

Front 372

Giberellins

Back 372

Plant hormone that influences cell elongation.

Front 373

Glottis

Back 373

The opening between the vocal cords at the upper part of the larynx.

Front 374

Glycogen

Back 374

Polysaccharide composed of many joined gluclose units, used as short term energy storage found in the muscle and liver tissue.

Front 375

Glycolisis

Back 375

The breaking down of the six carbon sugar (glucose) unto smaller carbon containing molecules yeilding ATP. Occurs in the cytoplasm of all living cells. Each molecule of glucose (six carbons) is broken down into two molecules of pruvic acid (pyruvate with three carbons each), two ATP molecules, and two hydrogen atoms (NADH).

This is an anaerobic reaction.

Front 376

Gnathostomata

Back 376

Group of vertabrates with jaws.

Front 377

Golgi Apparatus

Back 377

Found universally in both plant and animal cells, is typically comprised of a series of five to eight cup-shaped, membrane-covered sacs called cisternae that look something like a stack of deflated balloons. In some unicellular flagellates, however, as many as 60 cisternae may combine.Animal cells generally contain between ten and twenty, which are linked into a single complex by tubular connections between cisternae. This complex is usually located close to the cell nucleus.

Often considered the distribution and shipping department for the cell's chemical products

Front 378

Grana

Back 378

A series of stacked thylakoid disks containing chlorophyll; found in the inner membrane of chloroplasts.

Front 379

Gray Matter

Back 379

Nerve tissue within the brain is grayish in color.

Front 380

Gregor Mendel

Back 380

Studied the relationships between traits expressed in parents and offspring, and the heriditary factors that caused experession of traits.

Bred pea plants.

Front 381

Guard Cells

Back 381

One of the paired cells in the epidermis of a plant that control the opening and closing of a stoma of a leaf. When swollen with water, guard cells pull apart from each other, opening the stoma to allow the escape of water vapor and the exchange of gases. When drier, guard cells become more flaccid and move closer together, allowing the plant to conserve water. Unlike the other cells in the epidermis, guard cells have chloroplasts and conduct photosynthesis.

Front 382

Gymnosperms

Back 382

Plants that produce seeds without flowers.

Conifers (cone bearers) and cycads.

Front 383

Echinodermata

Back 383

Starfish, Sand dollars.

Front 384

Ecological Cycles

Back 384

1. Water Cycle
2. Carbon Cycle
3. Nitrogen Cycle
4. Phosphorous Cycle

Front 385

Ecology

Back 385

The science of the relationships between organisms and their enviroments.

Front 386

Ecosystem

Back 386

Complex of living organisms, their physical environment, and all their interrelationships in a particular unit of space. An ecosystem's abiotic (nonbiological) constituents include minerals, climate, soil, water, sunlight, and all other nonliving elements; its biotic constituents consist of all its living members.

Front 387

Ecotones

Back 387

A transitional zone between two communities containing the characteristic species of each.

Front 388

Ectoderm

Back 388

Outer layer of the gastrula which will later develop into the skin, central nervous system and some endocrine glands.

Front 389

Egestion

Back 389

Egestion is the discharge or expulsion of undigested material (food) from a cell in case of unicellular organisms, and from the digestive tract via the anus in case of multicellular organisms.

It should not be confused with excretion, which is getting rid of waste formed from the chemical reaction of the body, such as in urine, sweat, etc.

Front 390

Egg Cell

Back 390

Female gamete.

Front 391

Electron Cloud

Back 391

The term electron cloud is used to describe the area around an atomic nucleus where an electron will probably be.

Front 392

Electron Microscope

Back 392

Any of a class of microscopes that use electrons rather than visible light to produce magnified images, especially of objects having dimensions smaller than the wavelengths of visible light, with linear magnification approaching or exceeding a million (106).

Front 393

Electron Shell

Back 393

An electron shell may be thought of as an orbit followed by electrons around an atom's nucleus. The closest shell to the nucleus is called the "1 shell" (also called "K shell"), followed by the "2 shell" (or "L shell"), then the "3 shell" (or "M shell"), and so on further and further from the nucleus. The shell letters K, L, M, ... are alphabetical.

Front 394

Electron Transport

Back 394

A sequence of biochemical reduction-oxidation reactions that effects the transfer of electrons through a series of carriers. An electron transport chain, also known as the respiratory chain, forms the final stage of aerobic respiration. It results in the transfer of electrons or hydrogen atoms derived from the Krebs cycle to molecular oxygen, with the formation of water. At the same time it conserves energy from food or light in the form of ATP. The chain comprises a series of carrier molecules that undergo reversible reduction-oxidation reactions, accepting electrons and then donating them to the next carrier in the chain – a process known as electron flow. In the mitochondria, NADH and FADH2, generated by the Krebs cycle, transfer their electrons to a chain including coenzyme Q (see ubiquinone) and a series of cytochromes. This process is coupled to the formation of ATP at three sites along the chain. The ATP is then carried across the mitochondrial membrane in exchange for ADP. An electron transport c

Front 395

Electrons

Back 395

An electron is a subatomic particle. Carrying a negative charge, an electron orbits an atom’s nucleus and is bound to it by electromagnetic forces. An electron has a mass that is minuscule in comparison with even the smallest of atoms, coming in at about one thousandth the size of the tiniest atom. The electron is a basic unit of nature, meaning it cannot be broken down into smaller units.

Front 396

Element

Back 396

A substance composed of atoms having an identical number of protons in each nucleus. Elements cannot be reduced to simpler substances by normal chemical means

Front 397

Elongation Region

Back 397

Above the meristematic region, contains differentiated cells, large vacuoles are formed and cells grows.

Front 398

Embryo

Back 398

An organism in its early stages of development, especially before it has reached a distinctively recognizable form.

Front 399

Emigration

Back 399

Permanent one way movement out of the original range.

Front 400

Endocytic Vesicles

Back 400

Form when the plasma membrane of a cell surrounds a molecule outside of the membrane, then releases a memebrane-bound sack containing the desired molecule or substance into the cytoplasm.

Front 401

Endocytosis

Back 401

Cellular ingestion by which the plasma membrane folds inward to bring substances into the cell.

Front 402

Endoderm

Back 402

The inner layer of the gastrula that forms the digestive and respitory system.

Front 403

Endodermis

Back 403

The single layer of plant cells that is located between the cortex and the vascular (xylem and phloem) tissues

Front 404

Endoplasmic Reticulum

Back 404

membrane network within the cytoplasm of cells involved in the synthesis, modification, and transport of cellular materials.

Front 405

Endosymbiont Hypothesis

Back 405

concerns the mitochondria, plastids (e.g. chloroplasts), and possibly other organelles of eukaryotic cells. According to this theory, certain organelles originated as free-living bacteria that were taken inside another cell.

Front 406

Endothermic

Back 406

Of or relating to an organism that generates heat to maintain its body temperature, typically above the temperature of its surroundings; warm-blooded.

Front 407

Environment

Back 407

The totality of circumstances surrounding an organism or group of organisms, especially
the combination of external physical conditions that affect and influence the growth, development, and survival of organisms.

Front 408

Environmental Pollution

Back 408

The presence of substances and conditions that adversely affect the health and well-being of organisms within a community; usually substances in the air and water supply.

Front 409

Enzyme-Substrate Complex

Back 409

Occures when a substrate binds with the enzyme active site.

Front 410

Enzyme

Back 410

Organic catalyst, usually a protein, that speeds up a reactin in cells due to its particular shape.

Front 411

Epidermis

Back 411

The outermost layer of cells covering the leaves and young parts of a plant.

Front 412

Epiglottis

Back 412

The thin elastic cartilaginous structure located at the root of the tongue that folds to prevent food and liquid from entering the trachea during the act of swallowing.

Front 413

Epithelial Tissue

Back 413

thin layers of cells that make up layers of skin, lines ducts and the intestine, and covers the inside of the body cavity. Forms a barrier between the enviroment and the interior of the body.

Front 414

Equilibreal Life Strategy

Back 414

Also known as K selected

Front 415

Esophagus

Back 415

Muscular tube that conveys food by peristalsis from the pharynx to the stomach.

Front 416

Ethology

Back 416

The scientific study of animal behavior, especially as it occurs in a natural environment.

Front 417

Ethylene

Back 417

Produced by fruit as a hormone to speed ripening of climacteric fruits. This explains why some fruits ripen faster if they are stored in a plastic bag. It is used commercially in very small amounts to speed fruit ripening after harvesting.

Front 418

Eubacteria

Back 418

Domain name for bacteria.

Front 419

Eukaryota

Back 419

Domain name for Eukaryotes.

Front 420

Eukaryotes

Back 420

Any organism composed of one or more cells, each of which contains a clearly defined nucleus enclosed by a membrane, along with organelles (small, self-contained, cellular parts that perform specific functions). The organelles include mitochondria, chloroplasts, a Golgi apparatus, an endoplasmic reticulum, and lysosomes. All organisms except bacteria and archaea are eukaryotes; bacteria and archaea are prokaryotes.

Front 421

Evolution

Back 421

Change in the genetic composition of a population during successive generations, as a result of natural selection acting on the genetic variation among individuals, and resulting in the development of new species.

Front 422

Evolutionary Ecology

Back 422

Lies at the intersection of ecology and evolutionary biology. It approaches the study of ecology in a way that explicitly considers the evolutionary histories of species and the interactions between them. Conversely, it can be seen as an approach to the study of evolution that incorporates an understanding of the interactions between the species under consideration

Front 423

Excretory System

Back 423

Collects waste materials and expels them from the body.

Front 424

Exocytosis

Back 424

A process of cellular secretion or excretion in which substances contained in vesicles are discharged from the cell by fusion of the vesicular membrane with the outer cell membrane.

Front 425

Exothermic

Back 425

Chemical reaction that releases energy.

Front 426

Extinction

Back 426

Entire population of a particular species is eliminated.

Front 427

Extraembryonic Membranes

Back 427

Any of the membranous structures closely associated with or surrounding a developing vertebrate embryo, including the amnion, chorion, allantois, and yolk sac.

Front 428

Diploid

Back 428

Having two sets of chromosomes or double the haploid number of chromosomes in the germ cell, with one member of each chromosome pair derived from the ovum and one from the spermatazoon. The diploid number, 46 in humans, is the normal chromosome complement of an organism's somatic cells.

Front 429

Disaccharide

Back 429

A sugar consisting of two linked monosaccharide molecules. For example, sucrose (table sugar) comprises one glucose molecule and one fructose molecule bonded together.

Front 430

Dispersal/Dispersion

Back 430

Species movement away from an existing population or away from the parent organism.

Front 431

DNA

Back 431

A nucleic acid that carries the genetic information in the cell and is capable of self-replication and synthesis of RNA. DNA consists of two long chains of nucleotides twisted into a double helix and joined by hydrogen bonds between the complementary bases adenine and thymine or cytosine and guanine. The sequence of nucleotides determines individual hereditary characteristics.

DEOXYRIBONUCLEIC ACID

Front 432

DNA Replication

Back 432

Starts with one double-stranded DNA molecule and produces two identical copies of the molecule. Each strand of the original double-stranded DNA molecule serves as template for the production of the complementary strand.

Occures during the S (synthesis) phase

Front 433

Domains

Back 433

Archaea
Eubacteria (Prokaryotes)
Eukaryota

Front 434

Double-Helix

Back 434

The coiled structure of double-stranded DNA in which strands linked by hydrogen bonds form a spiral configuration, with the two strands oriented in opposite directions.

Front 435

B Cells

Back 435

A type of lymphocyte that, when stimulated by a particular antigen, differentiates into plasma cells that synthesize the antibodies that circulate in the blood and react with the specific antigens.

Front 436

Base

Back 436

PH above 7, also known as aklaline and accepts protons when disolved in water.

Front 437

Biennial

Back 437

A plant that normally requires two seasons to complete its life cycle, growing usually as a rosette in the first season and producing flowers and fruits and then dying in the second season.

Front 438

Bile

Back 438

Produced by the liver from broken down pigments and chemicals (often from pollutants and medications).

Front 439

Binomial Nomenclature

Back 439

The scientific naming of species whereby each species receives a Latin or Latinized name of two parts, the first indicating the genus and the second being the specific epithet. For example, Juglans regia is the English walnut; Juglans nigra, the black walnut.

Front 440

Biogeochemical Cycles

Back 440

Water cycle, carbon cycle, nitrogen cycle, phosphorous cycle.

Front 441

Biogeography

Back 441

The study of the distribution of species (biology), organisms, and ecosystems in space and through geological time. Organisms and biological communities vary in a highly regular fashion along geographic gradients of latitude, elevation, isolation and habitat area.

Front 442

Biomass

Back 442

Weight or total quantity of living organisms of one animal or plant species (species biomass) or of all the species in the community , commonly referred to as a unit area or volume of the habitat. The biomass in an area at a given moment is the standing crop.

Front 443

Biomedical Progress

Back 443

Advances in science and medicine that have inspired advances that correspond to historical inflection points of rapidly improving health.

Front 444

Biomes

Back 444

A major regional or global biotic community, such as a grassland or desert, characterized chiefly by the dominant forms of plant life and the prevailing climate.

Front 445

Biosphere

Back 445

The part of the earth and its atmosphere in which living organisms exist or that is capable of supporting life.

Front 446

Biotic

Back 446

Living component of a community (food source, predators ect.)

Front 447

Biotic Factors

Back 447

Relationships among living organisms in an ecosystem, include availablity of food, competition, symbiosis, predator/prey relationships, overpopulation.

Front 448

Blastula

Back 448

The stage of an embryo that consists of just over a hundred cells — a stage reached about one week after fertilization. At this stage the cells are just at the very beginning of cellular differentiation.

This is the stage of development where embryonic stems cells can be harvested for medical research.

Front 449

Blood

Back 449

The fluid consisting of plasma, blood cells, and platelets that is circulated by the heart through the vertebrate vascular system, carrying oxygen and nutrients to and waste materials away from all body tissues.

Front 450

Blood Tissue

Back 450

Consists of several cell types in a fluid called plasma, flows through vessels and heart, and is essential for carrying oxygen to the cells, fighting infections, and carrying nutrients and wasts to and from cells.

Front 451

Bone Tissue

Back 451

The major structural and supportive connective tissue of the body.

Also known as Osseous tissue .

Front 452

Brain

Back 452

The portion of the vertebrate central nervous system that is enclosed within the cranium, continuous with the spinal cord, and composed of gray matter and white matter. It is the primary center for the regulation and control of bodily activities, receiving and interpreting sensory impulses, and transmitting information to the muscles and body organs. It is also the seat of consciousness, thought, memory, and emotion.

Front 453

Bronchi

Back 453

The large air tubes leading from the trachea to the lungs that convey air to and from the lungs. The bronchi have cartilage as part of their supporting wall structure. The trachea divides to form the right and left main bronchi which, in turn, divide to form the lobar, segmental, and finally the subsegmental bronchi.

Front 454

Bronchioles

Back 454

A small terminal branch of the bronchus in the lungs. It lacks cartilage, and is lined with smooth muscle, which controls the lumen size and eventually branches out into alveoli.

Front 455

Bulbs

Back 455

63

Front 456

Abiotic

Back 456

non-living

Front 457

Abiotic Factors

Back 457

Physical non-living factors such as fire, pollution, sunlight, soil, light, weather conditions.

Front 458

Abscisic Acid

Back 458

A plant hormone that opens and closes the stomata (controlling water lost through transpiration and formation of winter buds that put the plant in a dormant state).

Front 459

Accessory Organs

Back 459

Part of the digestive system that include teeth, tongue, salivary glands, liver, gallbladder and pancrease.

Front 460

Acid

Back 460

PH below 7 and donates protons when disolved in water.

Front 461

Active Site

Back 461

The part of an enzyme at which catalysis of the substrate occurs.

Front 462

Active Transport

Back 462

The movement of a chemical substance through a gradient of concentration or electrical potential in the direction opposite to normal diffusion, requiring the expenditure of energy.

Front 463

Adaptive Radiation

Back 463

In biology, the evolution of an ancestral species, which was adapted to a particular way of life, into many diverse species, each adapted to a different habitat. Adaptive radiation has occurred in the evolution of many groups of organisms.

The most common example is Darwin's finches, 14 species of small land birds of the Galápagos Islands. All the finches derive from a single species of ground-dwelling, seed-eating finch that probably emigrated from the South American mainland. Because the environmental niches, or habitats, were unoccupied on the isolated islands, the ancestral stock was able to differentiate into diverse species; 3 species are ground-dwelling seedeaters, 3 live on cactus plants and are seedeaters, 1 is a tree-dwelling seedeater, and 7 are tree-dwelling insecteaters.

Front 464

Adipose Tissue

Back 464

A type of connective tissue that contains stored cellular fat.

Front 465

Aerobic

Back 465

Requires oxygen.

Front 466

Aerobic Respiration

Back 466

Requires oxygen, begins with glycolysis then krebs cycle, then electron transport chain.

Front 467

Aganatha

Back 467

Subphylum vertebrata for animals with no jaws.

Front 468

Age Composition

Back 468

The relative numbers of individuals of specific ages within the population.

Front 469

Aggregate Fruit

Back 469

Forms from many ovaries of a single flower (raspberry).

Front 470

Alimenary Canal

Back 470

Known as the G1 (gastroinsetinal) tract, includes the mouth, pharynx, esophagus, stomach, small instestine, large intestine, rectum and anus.

Front 471

Allantois

Back 471

A membranous sac that develops in the embryos of mammals, birds, and reptiles. It is important in the formation of the umbilical cord and placenta in mammals.

Front 472

Alleles

Back 472

One member of a pair or series of genes that occupy a specific position on a specific chromosome.

Front 473

Allopatric Speciation

Back 473

occurs when biological populations of the same species become isolated due to geographical changes such as mountain building or social changes such as emigration. The isolated populations then undergo genotypic and/or phenotypic divergence as: (a) they become subjected to different selective pressures, (b) they independently undergo genetic drift, and (c) different mutations arise in the populations' gene pools and over time will develop into two different species.

Front 474

Alternation of Generations

Back 474

In biology, alternation of a sexual phase (gametophyte) and a nonsexual phase (sporophyte) in the life cycle of an organism. The two phases, or generations, are often distinct in structure and sometimes in chromosome makeup. Alternation of generations is common in algae, fungi (see fungus), mosses, ferns, and seed plants. The character and extent of the two phases vary greatly among different groups of plants and algae. During the course of evolution, the gametophyte stage has been progressively reduced. Thus in higher (vascular) plants, the sporophyte is the dominant phase; in more primitive, nonvascular plants the gametophyte is dominant. Among animals, many invertebrates (e.g., protozoans, jellyfish, flatworms) have an alternation of sexual and asexual generations.

Front 475

Altruism

Back 475

Instinctive behavior that is detrimental to the individual but favors the survival or spread of that individual's genes, as by benefiting its relatives.

Front 476

Alveoli

Back 476

Any of the 300 million or so small air spaces in the lungs where carbon dioxide leaves the blood and oxygen enters it.

Front 477

Amensalism

Back 477

Interaction between coexisting populations of different species, one of which is adversely affected and the other unaffected.

Front 478

Amino Acids

Back 478

The building blocks of the proteins that are found in our bodies. The human body can produce 10 of its 20 amino acids, but the other 10, which are called essential amino acids, can only be obtained by eating the right foods. When the body doesn't get enough of these essential compounds, it will begin to break down its proteins in search of the nutrients it needs. Since the body stores fat and starch, but not amino acids, it is necessary for individuals to consume all the required essential nutrients

Front 479

Ammonification

Back 479

Part of the nitrogren cycle that results in the breakdown of organic matter such as dead animals and plants or waste materials like excrement. This breakdown is accomplished by scores of microorganisms which utilize dead organic material for energy and produce ammonia and related compounds as a byproduct of their metabolisms. Ammonification classically occurs in the soil, in an aerobic environment which gives the bacteria and other microorganisms oxygen to work with.

Front 480

Aminiotic Fluid

Back 480

Amniotic fluid is a clear, slightly yellowish liquid that surrounds the unborn baby (fetus) during pregnancy. It is contained in the amniotic sac.

The amniotic fluid helps:

•The developing baby to move in the womb, which allows for proper bone growth
•The lungs to develop properly
•Keep a relatively constant temperature around the baby, protecting from heat loss
•Protect the baby from outside injury by cushioning sudden blows or movements

Front 481

Amphibia

Back 481

The class of vertebrates that live on land but breed in water.

Salamaders, frogs (amniotic egg).

Front 482

Anabolism

Back 482

The metabolic synthesis of proteins, fats, and other constituents of living organisms from molecules or simple precursors. This process requires energy in the form of ATP. Drugs that promote such metabolic activity are described as anabolic.

Front 483

Anaerobic

Back 483

Without oxygen or not requiring oxygen.

Front 484

Anaerobic Pathways

Back 484

Glycolysis then fermentation

Front 485

Anaerobic Reaction

Back 485

No oxygen required, after glycolysis has occurred, repiration will continue on to fermentation.

Front 486

Anaphase

Back 486

The stage of mitosis and meiosis in which the chromosomes move to opposite ends of the nuclear spindle.

Front 487

Angiosperms

Back 487

A plant that produces flowers and fruit.

Front 488

Animal Evolution

Back 488

Precambrian, Paleozoic, Mesozoic, Cenozoic.

Front 489

Animals

Back 489

A multicellular organism of the kingdom Animalia, differing from plants in certain typical characteristics such as capacity for locomotion, nonphotosynthetic metabolism, pronounced response to stimuli, restricted growth, and fixed bodily structure.

Front 490

Annelida

Back 490

Segmented worms (earthworms, leeches).

Front 491

Annuals

Back 491

Living or growing for only one year or season

Front 492

Anther

Back 492

Sits atop the filament of the flower, contains pollen sacs.

Front 493

Antibodies

Back 493

Proteins in the human immune system that help the body fight foreign invaders, especially pathogens and toxins

Front 494

Antigens

Back 494

Toxins, bacteria, foreign cells ect.

Front 495

Antontie Van Leeuwenhoek

Back 495

A Dutch tradesman and scientist from Delft, Netherlands. He is commonly known as "the Father of Microbiology", and considered to be the first microbiologist. He is best known for his work on the improvement of the microscope and for his contributions towards the establishment of microbiology. Using his handcrafted microscopes, he was the first to observe and describe single-celled organisms, which he originally referred to as animalcules, and which we now refer to as micro-organisms. He was also the first to record microscopic observations of muscle fibers, bacteria, spermatozoa, and blood flow in capillaries (small blood vessels).

Front 496

Anus

Back 496

The opening at the lower end of the alimentary canal through which solid waste is eliminated from the body.

Front 497

Archea

Back 497

Any of various single-celled prokaryotes genetically distinct from bacteria, often thriving in extreme environmental conditions.

Front 498

Arteries

Back 498

Carry blood away from the heart.

Front 499

Aterioles

Back 499

One of the small terminal branches of an artery, especially one that connects with a capillary.

Front 500

Arthropoda

Back 500

Crabs, spiders, lobters, millipedes, insects.

Front 501

Asexual Plant Reproduction

Back 501

Vegetative porpagation -- tubers, rhizomes, stolens, bulmbs, corms.

Front 502

Atmosphere

Back 502

A gaseous layer that envelops the Earth and most other planets in the solar system

Front 503

Atoms

Back 503

A unit of matter, the smallest unit of an element, having all the characteristics of that element and consisting of a dense, central, positively charged nucleus surrounded by a system of electrons. The entire structure has an approximate diameter of 10 -8 centimeter and characteristically remains undivided in chemical reactions except for limited removal, transfer, or exchange of certain electrons.

Front 504

ATP

Back 504

"molecular unit of currency" of intracellular energy transfer.[1] ATP transports chemical energy within cells for metabolism. It is produced by photophosphorylation and cellular respiration and used by enzymes and structural proteins in many cellular processes, including biosynthetic reactions, motility, and cell division.[2] One molecule of ATP contains three phosphate groups, and it is produced by ATP synthase from inorganic phosphate and adenosine diphosphate (ADP) or adenosine monophosphate (AMP).

Front 505

Attached Ribosomes

Back 505

Endoplasmic reticulum with attached ribosomes is called rough. It looks bumpy under a microscope. Those attached ribosomes make proteins that will be used inside the cell and proteins made for export out of the cell.

Front 506

Autonomic

Back 506

Contains sympathetic and parasympathetic nervous systems.

Front 507

Autotrophs

Back 507

Organisms that produce their own food (plants and algae).

Front 508

Auxins

Back 508

Any of a group of hormones that regulate plant growth, particularly by stimulating cell elongation in stems and inhibiting it in roots. Influence the growth of stems toward light (phototropism) and against the force of gravity (geotropism).

Front 509

Aves

Back 509

Birds.

Spindle shaped body, long neck, paired limbs, most have wings for flying, four-toed feet, feathers, leg scales, bony skeleton, bones with air cavities, beak, no teeth, four chambered heart, warm blooded (endothermic), lings with thin air sacs, egg-laying.

Front 510

Axon

Back 510

An axon (also known as a nerve fiber) is a long, slender projection of a nerve cell, or neuron, that typically conducts electrical impulses away from the neuron's cell body or soma.

Front 511

Darwinian Concept of Natural Selection

Back 511

Darwin proposed natural selection but had no real knowledge of genetics.

Front 512

Decomposition Reaction

Back 512

Breakdown of a compount into its components.

AB = A + B

Front 513

Demographic Transition

Back 513

The term demographic transition originally described the major social shift that occurred in Western societies from the late nineteenth century to the 1930s. At that time, European societies, and their settler offshoots overseas, moved with considerable speed from a high-mortality, high-fertility population regime to low fertility and low mortality, with major social consequences. This historic shift saw the decline of family size from approximately six children per family to fewer than two. The transition also provided the preconditions for women to move from the private sphere and constant childbearing to the public domain and the expanding industrial work force.

Front 514

Denitrification

Back 514

Bacteria and fungi break down nitrates and release nitrogen gas back into the air.

Front 515

Density

Back 515

Number of organisms per area.

Front 516

Density-Dependent Factors

Back 516

Overcrowding and competition.

Front 517

Density-Independent Factors

Back 517

Fire, drought, pollution.

Front 518

Dicots

Back 518

Leaves have branched or networked veins, vascular bundles are arranged in rings, taproot system with smaller secondary roots, flowers have petals in multiples of four or five.

Front 519

Differential Reproduction

Back 519

The process in nature by which, according to Darwin's theory of evolution, only the organisms best adapted to their environment tend to survive and transmit their genetic characteristics in increasing numbers to succeeding generations while those less adapted tend to be eliminated.

Front 520

Diffusion

Back 520

Process by which molecules move from an area of higher concentration to an area of lower concentration.

Front 521

Digestion

Back 521

The process by which food is converted into substances that can be absorbed and assimilated by the body. It is accomplished in the alimentary canal by the mechanical and enzymatic breakdown of foods into simpler chemical compounds.

Front 522

Digestive System

Back 522

Serves as a processing plant for ingested food.

Front 523

Dihybrid Cross

Back 523

A cross between two parents where two traits are compared.

Example: AaBb AABB

Front 524

Cambrian Explosion

Back 524

The rapid diversification of multicellular animal life around the beginning of the Cambrian Period, resulting in the appearance of almost all modern animal phyla.

Front 525

Capillaries

Back 525

Tiny vessels that surround all tissues of the body and exchange carbon dioxed for oxygen.

Front 526

Carbohydrates

Back 526

Any of a group of organic compounds that includes sugars, starches, celluloses, and gums and serves as a major energy source in the diet of animals. These compounds are produced by photosynthetic plants and contain only carbon, hydrogen, and oxygen, usually in the ratio 1:2:1.

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Carbon Cycle

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Plants require carbon dioxide for photosynthesis, animal respiration releases carbon dioxide, animals eating plants consume carbon, when animals and plants die decomposers break down the organic matter.

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Cardiac Muscle

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The tissue forming the walls of the heart. Its strength and electrical properties are vital to the heart's ability to pump blood.

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Carnivores

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Animals that feed on only other animals (meat-eaters).

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Carrying Capacity

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The maximum number of individuals that a given environment can support without detrimental effects.

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Cartilage Tissue

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Reduced friction between bones and supports and connects them.

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Catabolism

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The metabolic breakdown of complex molecules into simpler ones, often resulting in a release of energy.

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Catalysts

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Substance that alters the velocity of a chemical reaction and may be recovered essentially unaltered in form and amount at the end of the reaction.

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Cell

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The smallest and most basic unit of life.

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Cell Body

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The part of a neuron containing the nucleus but not incorporating the axon and dendrites. Also called soma.

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Cell Membrane

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The semipermeable membrane that encloses the cytoplasm of a cell. Also called cytomembrane, plasmalemma, Also called plasma membrane.

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Cell Organelles of Plants & Animals

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Plants have three organelles that animal cells do not have: cell wall, central vacuole, and chloroplasts.

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Cell Theory

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1. All living things are made up of one or more cells.

2. Cells are the basic units of life.

3. All cells come from pre-existing cells.

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Cell Walls

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The rigid outermost cell layer found in plants and certain algae, bacteria, and fungi but characteristically absent from animal cells.

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Cellular Metabolism

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General term which includes all types of energy transformations including photosynthesis, respiration, growth, movement ect.

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Cellular Respiration

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The most efficient way for cells to harvest energy stored in food is through cellular respiration, a catabolic pathway for the production of adenosine triphosphate (ATP). ATP, a high energy molecule, is expended by working cells. Cellular respiration occurs in both eukaryotic and prokaryotic cells. It has three main stages: glycolysis, the citric acid cycle, and electron transport.

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Cellulose

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A fibrous, complex carbohydrate. It is the main component of plant tissues.

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Central Nervous System

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The portion of the vertebrate nervous system consisting of the brain and spinal cord.

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Central Vacuole

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In plant cells stores water and some nutrients for the cell. In animals, holds water or waste.

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Centrioles

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One of two cylindrical cellular structures that are composed of nine triplet microtubules and form the asters during mitosis and meosis.

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Cephalochordata

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A subphylum of the Chordata comprising the lampreys.

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Cerebellum

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Controls balance and muscle coordination (voluntary).

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Cerebrum

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The large rounded structure of the brain occupying most of the cranial cavity, divided into two cerebral hemispheres that are joined at the bottom by the corpus callosum. It controls and integrates motor, sensory, and higher mental functions, such as thought, reason, emotion, and memory.

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Chemical Bounds

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Any of several forces, especially the ionic bond, covalent bond, and metallic bond, by which atoms or ions are bound in a molecule or crystal.

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Chemical Reactions

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Occures when molecules interact with each other to form one or more molecules of another type.

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Chlorophyll

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The green pigment of plant materials which is responsible for the trapping of light energy for photosynthesis.

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Chloroplasts

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A complex, discrete green structure, or organelle, contained in the cytoplasm of plant cells. Chloroplasts are reponsible for the green color of almost all plants and are lacking only in plants that do not make their own food, such as fungi and nongreen parasitic or saprophytic higher plants. The chloroplast is generally flattened and lens-shaped and consists of a body, or stroma, in which are embedded from a few to as many as 50 submicroscopic bodies-the grana-made up of stacked, disklike plates. The chloroplast contains chlorophyll pigments, as well as yellow and orange carotenoid pigments. Chloroplasts are thus the central site of the photosynthetic process in plants. The chloroplasts of algae are simpler than those of higher plants and may contain special, often conspicuous, starch-accumulating structures called pyrenoids.

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Chondrichtyes

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Fish with a cartilaginous endoskeleton, two-chambered heart, 5-8 gill pairs, no swim bladder or lung, and internal fertilization.

Sharks, Rays ect.

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Chordata

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Phylum for fish, amphibians, reptiles, birds, mammals, lampreys.

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Chorioallantoic Membrane

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A vascular membrane found in eggs of some amniotes, such as birds and reptiles. It is formed by the fusion of the mesodermal layers of two developmental structures: the allantois and the chorion. In mammals, this structure forms the placenta.

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Chorion

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The outer membrane enclosing the embryo in reptiles, birds, and mammals. In placental mammals it contributes to the development of the placenta.

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Chromatids

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In a cell that is getting ready to divide, each strand of chromatin is duplicated.

(Half of a chromosome)

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Chromatin

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DNA wrapped around histones, not during cell division.

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Chromosomes

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A threadlike linear strand of DNA and associated proteins in the nucleus of eukaryotic cells that carries the genes and functions in the transmission of hereditary information.

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Circulatory System

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The bodily system consisting of the heart, blood vessels, and blood that circulates blood throughout the body, delivers nutrients and other essential materials to cells, and removes waste products. Also called cardiovascular system.

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Class

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A taxonomic category ranking below a phylum or division and above an order.

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Cleavage

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When a zygote undergoes a series of cell divisions.

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Climax Community

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Stable community, the community best suited to the climate and soil conditions, and achieves a homeostasis.

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Closed Circulatory System

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Blood flow is confined to the vessels. Common in vertebrates.

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Closed Community

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Intentionally limits links with other communities.

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Cnidaria

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Phylum for jellyfish, sea anemones, hydra...ect

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CO2 Fixation

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During photosynthesis, the process by which plants convert carbon dioxide from the air into organic molecules.

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Codon

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A sequence of three adjacent nucleotides constituting the genetic code that determines the insertion of a specific amino acid in a polypeptide chain during protein synthesis or the signal to stop protein synthesis.

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Coenzymes

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A nonproteinaceous organic substance that usually contains a vitamin or mineral and combines with a specific protein, the apoenzyme, to form an active enzyme system.

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Cofactor

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A substance, such as a metallic ion or coenzyme, that must be associated with an enzyme for the enzyme to function.

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Cohesion

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Hydrogen bonding between water molecules.

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Conhesion-Tension Process

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The supporting and water-conducting tissue of vascular plants, consisting primarily of tracheids and vessels; woody tissue.

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Community

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A group of plants and animals living and interacting with one another in a specific region under relatively similar environmental conditions.

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Community Structure

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Refers to the characteristics of a specified community, including the types of species that dominate, major climatic trends of the region, and whether the community is opened or closed.

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Competition

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The simultaneous demand by two or more organisms for limited environmental resources, such as nutrients, living space, or light.

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Competitive Exclusion

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The assumption that two species with identical ecological requirements cannot coexist in the same niche in the same location indefinitely. One species will eventually supplant the other, unless they evolve adaptations that allow them to partition the niche and thereby reduce competition.

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Compound

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Formed when two or more different atoms bound together chemically to form a unique substance.

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Compound Fruits

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Develops from several ovaries in either a single flower or multiple flowers.

Example: Raspberries and Pineapples.

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Conditioning

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A process of behavior modification by which a subject comes to associate a desired behavior with a previously unrelated stimulus.

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Connective Tissue

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Tissue arising chiefly from the embryonic mesoderm that is characterized by a highly vascular matrix and includes collagenous, elastic, and reticular fibers, adipose tissue, cartilage, and bone. It forms the supporting and connecting structures of the body.

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Convergent Evolution

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The adaptive evolution of superficially similar structures, such as the wings of birds and insects, in unrelated species subjected to similar environments.

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Corms

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A short thick solid food-storing underground stem, sometimes bearing papery scale leaves, as in the crocus or gladiolus.

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Cortex

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The region of tissue in a root or stem lying between the epidermis and the vascular tissue.

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Covalent Bond

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A chemical bond formed by the sharing of one or more electrons, especially pairs of electrons, between atoms.

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Cristae

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Folded internal membrane of the mitochondria, where cellular respiration occurs.

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Crop

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An organ that stores food until it is processed for absorption.

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Crossing Over

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The exchange of genetic material between homologous chromosomes that occurs during meiosis and contributes to genetic variability.

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Cud

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Food regurgitated from the first stomach to the mouth of a ruminant and chewed again.

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Cuticle

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Maintains the leaf's moisture balance and covers most leaf surfaces.

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Cytochromes

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Any of a class of iron-containing proteins important in cell respiration as catalysts of oxidation-reduction reactions.

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Cytokinesis

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Process that divides cells in two.

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Cytokinins

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Hormones that promote cell division and fruit development in plants.

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Cytoplasm

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Small gel-like substance residing between the cell membrane holding all the cell's internal sub-structures (called organelles), except for the nucleus.

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Cytoplasmic Organelles

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All organelles outside the nucleus but within the cell membrane, that exist within the cytoplasm.

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Cytoskeleton

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Provides structural support to a cell. Includes, mictrofilaments, microtubules, and centrioles.