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417 Cards in this Set
- Front
- Back
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Abiotic Factors |
Nonliving factors in an ecosystem
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Abscisic acid (ABA)
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Plant hormone that inhibits growth
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Accessory pigments
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(Also Antennae) Molecules that assist in photosynthesis by capturing and passing on photons of light to chlorophyll a and expanding the range of light that can be used to produce sugar. Examples are chlorophyll b and the caretenoids.
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Acoelomate
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An animal that has no true coelom; ex: flatworms
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Actin
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Protein that makes up the thin myofilaments in skeletal muscle
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Active Transport
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movement of particles against a gradient, from low concentration to high concentration. This always requires the expenditure of energy
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Adventitious roots
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roots that rise above the ground; examples are aerial roots and prop roots
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Agonistic behavior
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aggressive behavior
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Alcohol fermentation
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The process by which certain cells convert pyruvic acid or pyruvate from glycolysis into ethyl alcohol and carbon dioxide in the absence of oxygen
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Allantois
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Extra embryonic membrane in a bird's egg. Exchanges respiratory gases to and from the embryo
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Alleles
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Alternate forms of a gene. For example, there are two of these for height in pea plants: tall and dwarf.
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Alveoli
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Microscopic air sacs in the lung where diffusion of the respiratory gases, oxygen and carbon dioxide occurs
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Amnion
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Membrane that encloses the embryo in protective amniotic fluid
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Amylase
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Enzyme that digests starch
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Analogous structures
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Structures, such as a bat's wing and a fly's wing, that have the same function but not the same underlying structure (not evidence of a common origin).
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Aneuploidy
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any abnormal condition of the chromosomes
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Angiosperms
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Anthophyta or flowering plants
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Anion
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a negative ion
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Antennae
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(Also accessory pigments) Molecules that assist in photosynthesis by capturing and passing on photons of light to chlorophyll a and expanding the range of light that can be used to produce sugar. Examples are chlorophyll b and the caretenoids.
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Anther
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Male part of flower where sperm (pollen) is produced by meiosis. Sits atop the filament
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Antheridia
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structures located on the tips of a gametophyte plant and produce sperm
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Antibodies
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Immunoglobins. Part of the third line of defense, the specific immune response. Each molecule is a Y shaped molecule consisting of four polypeptide chains
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Anticodon
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The three nucleotide sequence associated with tRNA
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Antigens
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anything that triggers an antibody response
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Apoptosis
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programmed cell death
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Archaeopteryx
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intermediate fossil that shows both reptile and bird characteristics
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Archegonia
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structures located on the tips of a gametophyte plant and that produces eggs.
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Associative learning
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one type of learning in which one stimulus becomes linked to another through experience.
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ATP
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special high energy molecule that stores energy for immediate use in the cell
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ATP synthase
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structure in the membranes of mitochondria and chloroplasts where ATP is formed
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Autonomic nervous system
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part of the nervous system that controls automatic functions, such as heart and breathing rate
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Autosomes
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chromosomes other than the sex chromosomes. Humans have 44 in each cell
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Auxins
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growth hormones in plants that are responsible for phototropisms and apical dominance, the preferential growth of a plant towards the sun
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Backcross
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Testcross. a technique to determine whether an individual plant or animal showing the dominant trait is homozygous dominant or heterozygous
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Bacterial transformation
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the ability of bacteria to alter their genetic makeup by uptaking foreign DNA from another bacerial cell and incorporating it into their own. Discovered by Griffith
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Base-pair substitution
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a mutation where one nucleotide is substituted for a correct one in a DNA strand
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Bicarbonate ion
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the most important buffer in human blood. It is responsible for keeping the pH of blood at 7.4
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Bile
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chemical produced in the liver and released from the gallbladder that emulsifies fats. It is not an enzyme.
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Binomial nomenclature
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system of taxonomy that we use today, developed by Carl von Linné. In this system, every organism has a two part name, like Homo Sapiens.
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Biosphere
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the global ecosystem
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Biotechnology
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branch of science that uses recombinant DNA techniques for practical purposes, also called genetic engineering
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Biotic factor
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includes all the organisms with which an organism might react in an ecosystem
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Biotic potential
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the maximum rate at which a population could increase under ideal conditions
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Bottleneck effect
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natural disasters such as fire, earthquake, and flood reduce the size of a population nonselectively, resulting in a loss of genetic variation. The resulting population is much smaller and not representative of the original one. Certain alleles may be under or overrepresented compared with the original population.
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Budding
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splitting off of new individuals from existing ones. how reproduction occurs in hydra.
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Buffers
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chemicals that resist a change in pH
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C-4 photosynthesis
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modification for dry environments. C-4 plants exhibit modified anatomy and biochemical pathways, which enable them to minimize excessive water loss and maximize sugar production.
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Calvin cycle
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cyclical process that produces sugar. It occurs during the light-independent reactions.
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Carbon fixation
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incorporation of carbon dioxide into a sugar. Occurs during the Calvin cycle.
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Cardiac sphincter
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band of muscle at the top of the stomach that keeps acidified food in the stomach from backing up into the esophagus and burning it.
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Carotenoids
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photosynthetic antennae pigments. they are orange and yellow.
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Carpel
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Female part of the flower, produce the female gametophytes, ova. Each consists of an ovary, stigma and style. Also called the pistil.
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Carrying Capacity (K)
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a limit to the number of individuals that can occupy one area at a particular time.
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Cation
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a positive ion.
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Centrioles
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responsible for division of the cytoplasm in animal cells; they are not present in plant cells. They consist of 9 triplets of microtubules arranged in a circle.
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Centromere
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specialized region of a chromosome that holds two sister chromatids together
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Centrosome
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consist of two centrioles at right angles to each other. Important during cell division in animal cells.
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Chemiosmosis
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how ATP is produced during oxidative phosphorylation. Protons only flow through the special ATP synthetase channels and transfer energy to molecules of ATP.
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Chitin
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a polysaccharide that makes up the exoskeleton of insects and the cell walls of fungi.
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Chloroplasts
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type of plastid that carries out photosynthesis
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Chorion
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membrane that lies under the shell of an egg and allows for diffusion of respiratory gases between the outside environment and the inside of the shell.
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Chromatin network
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DNA in the nucleus that is wrapped with special proteins called histones into a visible network.
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Chromoplasts
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type of plastid that stores pigments that are responsible for the bright colors in fruit and flowers
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Classical conditioning
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type of associative learning. Pavlov trained dogs to associate the sound of a bell with food. The result was that dogs would salivate upon merely hearing the sound of the bell even though no food was present.
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Cleavage
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rapid mitotic cell division of the zygote that begins immediately after fertilization
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Cnidocytes
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cells that house the stingers in cnidarians
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Codominance
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an inheritance pattern where both traits show at once. In humans, a person who had 2 different genes for blood type, A and B, has type AB blood.
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Codon
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the three-nucleotide sequence associated with mRNA.
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Coelomate
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an animal that has a true coelom; all chordates are coelomates
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Coenzymes
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vitamins that assist in the normal functioning of enzymes
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Coevolution
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the mutual evolutionary set of adaptations of two interacting species
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Cofactors
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Minerals that assist in the normal functioning of enzymes
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Cohesion tension
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The attraction of like molecules to stick together. water molecules tend to stick together because they exhibit strong cohesion tension.
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Collenchyma cells
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Plant cells that have unevenly thickened cell walls but lack secondary cell walls. The strings of celery consist of collenchyma cells.
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Colon
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another name for large intestine
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Commensalism
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symbiotic relationship in which one organism benefits and one is not affected by another organism.
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Community
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Consists of all the organisms living in one area
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Companion cells
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make up phloem vessels, along with sieve tube elements
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Conjugation
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a primitive form of sexual reproduction where individuals exchange genetic material.
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Continental drift
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The theory that states that the continents are floating and moving very slowly. Over millions of years, seven separate continents formed from Pangea.
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Contractile vacuole
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structure found in freshwater protista, like paramecia and amoeba, that pumps out excess water that diffuses inward because the organisms live in an environment that is hypotonic.
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Convergent evolution
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type of evolution where unrelated species occupying the same environment and subjected to similar selective pressures show similar adaptations. The classic example is the whale and the fish.
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Cortex
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Specialized region in a plant root or stem for storage and support.
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Cotyledon
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Food for the growing embryo in a dicot seed. The cells that make this up are triploid.
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Covalent bonds
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bonds formed between atoms where electrons are shared.
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CAM (Crassulacean acid metabolism )
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a form of photosynthesis that is an adaptation for dry conditions. These plants keep there stomates closed during the day and open at night, the reverse of how most plants behave.
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Cristae
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series of inner membranes in mitochondria where cell respiration occurs
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Crop
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structure in birds, insects, and earthworms, among others, for temporary storage of food.
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Crossing over
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A normal process in which homologous chromatids exchange genetic material. Crossover is important because it increases variation in the gametes.
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Cutin
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waxy coating on the leaves that helps prevent excess water loss from the plant
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Cyclosis
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Movement of cytoplasm around the cell
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Cystic fibrosis
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the most common lethal genetic disease in the United States, 1 out of 25 caucasians is a carrier. Characterized by build up of extracellular fluid in the lungs and digestive tract.
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Cytochromes
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proteins that play a key role in electron transport chains in mitochondria and chloroplasts
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Cytokinesis
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division of the cytoplasm. In animal cells, a cleavage furrow forms down the middle of the cell as the cytoplasm pinches inward and the two daughter cells separate from each other. In plant cells, a cell plate forms down the middle of the cell.
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Cytokinins
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Plant hormones that stimulate cell division and cytokinesis
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Cytoplasm
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The entire region between the nucleus and plasma membrane
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Cytosol
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Semiliquid portion of the cytoplasm
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Decomposer
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Organisms that play a vital role in the ecosystem and that recycle dead organic matter.
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Dehydration synthesis
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Also known as synthesis. Process by which molecules are bonded together to form a larger molecule with the removal of water.
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Deletion
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A mutation where a piece of gene, or chromosome is lost
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Denature
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Characteristic of proteins; a change in shape that stops the protein from functioning.
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DNA
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the heritable material, passed from parent to offspring
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Diastole
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Relaxation of the ventricles of the heart. Normal diastolic pressure is 120 mm Hg.
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Dicotyledon
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Plant whose seed easily breaks in two
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Diffusion
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The flow of molecules from a higher concentration to a lower concentration. There are two types: simple and facilitated.
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Digestion
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Enzymatic breakdown, hydrolysis, of food so it is small enough to be assimilated into the body.
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Dipeptide
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A molecule consisting of two animo acids
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Directional Selection
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Changing environmental conditions give rise to this type of natural selection. One phenotype replaces another in the gene pool.
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Disruptive Selection
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This typeof natural selection increases the number of extreme types in a population at the expense of intermediate forms.
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Divergent Evolution
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Occurs when a population becomes isolated (for any reason) from the rest of the species and becomes exposed to new selective pressures, causing it to evolve into a new species. Homologous structures are evidence of this.
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DNA polymerase
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the enzyme that catalyzes the elongation of the new DNA strands during replication.
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Domain
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In the newest system of classification, all organism are classified in one of three domains, which are further divided into kingdom, phylum, class, order, family, genus, and species.
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Duodenum
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The first 10 inches of the small intestine; where all the digestion is completed
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Ecosystem
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Includes all the organisms in a given area as well the abiotic factors with which they interact.
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Ectotherm
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An animal, such as a fish, amphibian, or reptile, that must use environmental energy or behavioral adaptations to its body temperature, cold-blooded.
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Egestion
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Removal of metabolic waste
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Electron transport chain (ETC)
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consists of a series of molecules within the cristae membrane of mitochondria that provides the energy to phosphorylate ADP into ATP during oxidative phosphorylation.
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Endoderm
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The innermost layer of an embryo, which develops into the viscera or the digestive system.
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Endoplasmic Reticulum
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system of transport channels within the cytoplasm of a eukaryotic cell.
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Endosperm
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Food dor the growing embryo in a monocot seed. The cells that make up the endosperm are triploid.
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Endotherm
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An animal that uses metabolic energy to maintain constant body temperature; warm-blooded.
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Energy of Activation
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The amount of energy required to start a reaction.
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Eohippus
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a transition fossil that demonstrates that the ancient horse is an ancestor of the modern horse, Equus.
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Epicotyl
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Part of the embryo in a seed that becomes the upper part of the stem and leaves
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Epididymis
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Part of the testes where the sperm becomes motile
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Epiglottis
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Flap of cartilage in the back of the throat that directs food to the esophagus
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Erythrocytes
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red blood cells
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Ethylene
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Gaseous plant hormone that promotes fruit ripening
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Eukaryotes
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Cells that contain internal membranes; opposite of prokaryotes
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Excited state
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when an atom absorbs energy, its electrons move to a higher energy level
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Excretion
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Removal of metabolic wastes
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Exocytosis
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The release of substances from a cell
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Exons
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expressed sequences of DNA. DNA that codes for particular polypeptides
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Extremophiles
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organisms that live in extreme environments, like methanogens, halophiles, and thermophiles. Make up the domain Archaea
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flavin adenine dinucleotide (FAD)
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coenzyme that shuttles protons and electrons from glycolysis and the Krebs cycle to the electron transport chain
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Fermentation
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Anaerobic phase of cell respiration
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Filament
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Threadlike structure that holds up the anther in the male part of a flower.
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Filtration
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Process that occurs in the nephron where nutrients and wastes diffuse from the glomerulus into Bowman's capsule
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Final transcript
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the strand of mRNA that is sent to the ribosome after processing. It is much shorter than the initial transcript.
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Fission
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Division of an organism into two new cells. Reproduction in protists.
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Fixed action pattern
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Innate, highly stereotypical behavior, which once begun is continued to completion, no matter how useless or silly looking. They are initiated by external stimula called sign stimuli.
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Food chain
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pathway along which food is transferred from one trophic or feeding level to another.
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Founder Effect
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a small population, which is not representative of the largest population, breaks away form the larger one to colonize a new area. Rare alleles may be under or overrepresented.
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Fragmentation
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a single parent organism breaks into parts that regenerate into new individuals. Reproduction in sponges, planaria, and sea stars.
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Frameshift
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an error in the DNA in which the entire reading frame is altered. This can be caused by an insertion or deletion.
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glyceraldhyde-3-phosphate (G3P) (PGAL)
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First sugar produced by photosynthesis
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Gametangia
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in primitive plants, a protective jacket of cells in which gametes and zygotes develop and which prevents drying out.
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Gametophyte
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Monoploid generation of a plant
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Gastrin
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Digestive hormone that stimulates sustained secretion of gastric juice from the stomach
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Gastrovascular cavity
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Gastrocoel, primitive digestive cavity in hydra
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Gastrulation
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The process by which a blastula develops into a gastrula with the formation of three embryonic layers
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Gel electrophoresis
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process that separates large molecules of DNA on the basis of their rate of movement through an agarose gel in an electric field.
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Gene flow
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movement of alleles into or out of a population
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Genetic drift
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Change in a gene pool due to chance (Bottleneck and Founder effects)
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Genetic engineering
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Using recombinant DNA techniques for practical purposes, also called biotechnology
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Genome
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An organism's genetic material. The human one consists of 3 billion base pairs of DNA and about 30,000 genes.
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Genotype
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The genes an organism has.
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Geographic isolation
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separation by geography
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Gibberellins
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plant hormones that promote stem and leaf elongation
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Gizzard
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Structure in birds, insects, and earthworms where mechanical digestion of food occurs.
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Global warming
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Increase in average temperature of Earth. Due to the greenhouse effect.
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Glucagon
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Hormone released by the pancreas that raises blood sugar.
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Glycerol
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Combines with fatty acids to make lipids.
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Glycolysis
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the anaerobic phase of aerobic respiration. One molecule of glucose breaks apart into two molecules of pyruvate.
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Golgi apparatus
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organelle that packages and secretes substances for the cell
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Gradualism
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the theory that organisms descended from a common ancestor gradually, over a long period of time, in a linear or branching fashion.
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Grana
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Membranes within chloroplasts that consist of thylakoid membranes and are the sites of the light-dependent reactions of photosynthesis.
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Greenhouse effect
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Carbon dioxide and water vapor in the air absorb much of the infrared radiation reflecting off Earth, causing the average temperature on Earth to rise.
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Gross primary productivity
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Amount of energy converted to chemical energy per unit time in an ecosystem.
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Ground state
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Condition of an electron when it is not excited. It is in its lowest energy level.
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Guard cells
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Modified epithelium containing chloroplasts that control the opening and closing of the stomates by a change in shape
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Gymnosperms
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conifers or cone-bearing trees
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Habituation
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One of the simplest forms of learning in which an animal comes to ignore a persistent stimulus so it can go about its business.
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Half-life
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Amount of time it takes for a radioactive isotope to decay to half its mass.
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Halophiles
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organisms that thrive in environments with high salt concentrations like the Great Salt Lake.
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Heat of vaporization
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the amount of energy required to change a specified amount of liquid into a gas.
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Heliobacter pylori
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Bacteria that is the cause of most ulcers
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Hemocoels
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Sinuses. Cavities in the body of insects, like grasshoppers, for exchange of nutrients and wastes.
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Hemophilia
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An inherited disease caused by the absence of one or more proteins necessary for normal blood clotting.
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Hermaphrodites
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organisms that contain both female and male sex organs.
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Heterotroph hypothesis
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theory that states that the first cell on Earth were anaerobic, heterotrophic prokaryotes.
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Heterotrophs
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organisms that must take in all their nutrients
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Histamine
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important chemical in the immune system that triggers vasodilation (enlargement of blood vessels), which increases blood supply to an area. Histamine is also responsible for the symptoms of the common cold, all in attempt to rid the body of invaders.
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Histones
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special proteins that wrap around DNA, forming chromatin networks
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Homeostasis
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Internal stability
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Homeotherm
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Endotherm. Animals that maintain a consistent body temperature. Examples are birds, mammals, and some reptiles.
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Homologous structures
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The same internal bone structures with some variation.
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Huntingdon's disease
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A degenerative inherited disease of the nervous system resulting in certain and early death. The gene that causes it is dominant, and onset is usually in middle age.
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Hydrogen bonding
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an intermolecular attraction between molecules that exert a strong pull on their electrons. This attraction keeps the two strands of a DNA molecule together.
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Hydrophilic
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Soluble in water. Either polar or ionic.
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Hydrophobic
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Insoluble in water. Nonpolar.
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Hypertonic
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Having greater concentration of solute than another solution
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Hypocotyl
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part of the embryo in a seed that becomes the lower part of the stem and the roots.
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Hypothalamus
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Major gland in the brain that is the bridge between the endocrine and nervous systems.
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Hypotonic
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Having less concentration of solute than another solution.
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Imprinting
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Learning that occurs during a sensitive or critical period in the early life of an individual and is irreversible for the length of that period.
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Incomplete dominance
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an inheritance pattern characterized by blending of traits. An example is crossing an animal with black fur with one with white fur, and producing an offspring with gray fur.
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Ingestion
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Intake of nutrients
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Initial transcript
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Strand of mRNA before it is processed. It is much longer than the final transcript.
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Insertion
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A mutation where one nucleotide inserts itself into an existing strand; can cause a frameshift
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Insulin
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Hormone released by the pancreas that lowers blood sugar
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Intermolecular attraction
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Attraction between molecules. One example is hydrogen bonding.
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Introns
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Intervening, noncoding sequences of DNA located between genes
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Inversion
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A chromosomal fragment breaks off and reattaches to its original chromosome but in the reverse orientation
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Ionic bonds
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Bonds between atoms that form by transferring electrons
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Irritability
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Ability to respond to stimuli
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Isotonic
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Solutions containing equal concentrations of solute
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Junk
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Noncoding regions of DNA. Most of the human genome consists of these noncoding regions.
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Karyotype
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Procedure that analyzes the size, shape, and number of chromosomes
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Krebs cycle
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Also known as the citric acid cycle; the first stage of the aerobic phase of cellular respiration. It occurs in the inner matrix of mitochondria.
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Lacteal
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Structures within the villi that line the small intestine and that absorb fatty acids and glycerol into the lymphatic system.
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Lactic acid fermentation
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Occurs during strenuous exercise when the body cannot keep up with the increased demand for oxygen by skeletal muscles and pyruvic acid converts to lactic acid, which builds up in the muscle and causes fatigue and burning.
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Law of dominance
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Mendel's first law that states that when two organisms, each homozygous for two opposing traits are crossed, the offspring will by hybrid but will exhibit only the dominant trait.
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Law of independent assortment
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Best demonstrated by the dihybrid cross. A cross that is carried out between two individuals hybrid for two or more traits that are not one the same chromosome- resulting in phenotype ratio 9:3:3:1
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Law of segregation
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During the formation of gametes, the traits carried on homologous chromosomes separate
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Learning
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sophisticated process in which the respondes of the organism are modified as a result of experience
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Leucoplast
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Type of plastid that stores starch
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Leukocyte
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White blood cells
|
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Light-dependent reactions
|
Part of photosynthesis that requires light, produces ATP, and releases oxygen.
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Light-independent reactions
|
Part of photosynthesis that does not require light directly, only the products of light dependent reactions. Sugar (PGAL) is produced.
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Limiting factors
|
those factors that limit population growth. They are divided into two categories, density dependent and density independent factors.
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Lipid
|
One type of organic molecule. It consists of one glycerol plus three fatty acids.
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Locomotion
|
Moving from place to place.
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Lysosome
|
Cell organelle that consists of digestive (hydrolytic) enzymes and its principal site of intracellular digestion in the cell.
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Macroevolution
|
Refers to speciation, the formation of an entirely new species.
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Malpighian tubule
|
structures in grasshoppers for removal of the nitrogenous waste uric acid
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Malthus
|
Published a treatise on population growth, disease, and famine in 1798 that influenced Darwin in the development of his theory of natural selection. He stated that populations tend to grow exponentially, to overpopulate, and to exceed their resources.
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Meiosis
|
Type of cell division in sexually reproducing organisms that produces monoploid gametes.
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Medusa
|
Upside down bowl shaped body type.
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Menopause
|
Cessation of the menstrual cycle.
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Meristem tissue
|
Plant tissue that is always dividing. An example is cambium tissue.
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Mesoderm
|
The middle layer of an embryo that develops into blood, bones, and muscle.
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Mesoglea
|
The middle later of a two layered animal, like sponges or hydra, which holds the two layers together.
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mRNA
|
Carries messages directly from DNA in the nucleus to the cytoplasm during protein synthesis.
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Metabolism
|
The sum total of all life functions.
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Methanogens
|
Organisms that obtain energy in a unique way by producing methane from hydrogen
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Microevolution
|
Changes in one gene pool of a population over generations
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Microfilaments
|
Made of the protein actin and help support the shape of the cell. They enable animal cells to form a cleavage furrow during cell division or the amoeba to move by sending out pseudopods.
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Microtubules
|
Thick hollow tubes that make up the cilia, flagella, and spindle fibers.
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Middle lamella
|
Layer of tissue between two cell walls of adjacent plant cells
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Mitochondrion
|
Cell organelle that produces ATP. Present in both plant and animal cells.
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Mitosis
|
Type of cell division for growth and repair that produces two genetically identical daughter cells with the same chromosome number as the parent cell. Consists of prophase, metaphase, anaphase, and telophase.
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Molecule
|
The name given to two or more atoms joined by a covalent bond.
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Monocotyledon
|
Plant whose seed does not break into two parts
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Monohybrid cross
|
A cross between two organisms that are heterozygous for one trait.
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Monoploid
|
Haploid; having half the chromosone number
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Monotremes
|
Egg laying mammals, like the platypus and the spiny anteater, which derive nutrients from a shelled egg.
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Multiple alleles
|
when there are more than two allelic forms of a gene.
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Mutation
|
Any change in a gene or chromosome
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Mutualism
|
Symbiotic relationship where both organisms benefit. An example is the bacteria that live in the human intestine and that produce vitamins.
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Mycorrhizae
|
Symbiotic structures consisting of the plant's roots intermingled with the hyphae (filaments) of a fungus, which greatly increase the quantity of nutrients the plant can absorb.
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Myosin
|
Myofilaments that make up the thick filaments in skeletal muscle
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nicotinamide adenine dinucleotide (NAD)
|
Coenzyme that shuttle protons or electrons from glycolysis and the Krebs cycle to the electron transport chain.
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Nematocysts
|
Stingers found in cnidocytes of cnidarians
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Nephridia
|
Structure in earthworks for excretion of the nitrogen waste urea
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Net primary productivity
|
Gross primary productivity minus the energy used by the primary producers for respiration
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|
Nondisjunction
|
An error that sometimes happens during meiosis in which homologous chromosomes fail to separate as they should.
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Notochord
|
A rod that extends the length of the body and serves as a flexible axis. This is characteristic of all chordates.
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Nucleolus
|
Where components of ribosomes are synthesized. This is a prominent region within the nucleus of a cell that is not dividing.
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Objective lens
|
The lens on a light microscope that is closest to the stage.
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Ocular lens
|
Eyepiece of a microscope
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|
|
Omnivores
|
Animals that normally eat both meat and vegetables in their diet.
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Oogenesis
|
Formation of ova by meiotic cell division.
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Operant conditioning
|
Trial and error learning
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|
|
Organogenesis
|
Process by which cells continue to differentiate, producing organs from the three embryonic germ layers.
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Origins of replication
|
Special sites where replication begins in eukaryotic cells.
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Osmosis
|
diffusion of water across a membrane
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|
|
Ovary
|
Swollen part of pistil of a flower that contains the ovule, where one or more ova are produced.
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Oviduct (Fallopian tube)
|
Where fertilization occurs. After ovulation, the egg moves through the oviduct to the uterus.
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Ovule
|
The structure within the ovary of a flower where the ova (female gametophytes) are produced.
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Oxidation
|
Loss of electrons
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|
Oxidative phosphorylation
|
Process that provides most of the energy (ATP) produced during cell respiration
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|
|
Oxytocin
|
Hormone secreted by the posterior pituitary that stimulates the uterus and causes contractions during labor
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|
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Parallel evolution
|
Two related species that have made similar evolutionary adaptations after their divergence from a common ancestor
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Parasitism
|
Symbiotic relationship where on organism, the parasite, benefits while the host is harmed
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Parenchyma cells
|
Traditional looking plant cell. Have a primary cell wall that is thin and flexible but lack a secondary cell wall.
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Parthenogenesis
|
The development of an egg without fertilization. The resulting adult is haploid.
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Pathogen
|
Organism that causes disease
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Peptidases
|
Enzymes that break down proteins into amino acids
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Phagocytosis
|
Cellular process of engulfing food and encapsulating it in a vacuole.
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Pharynx
|
Throat
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Phenylketonuria
|
An inherited disease characterized by the inability to break down the amino acid phenylalnine. Requires elimination of phenylalnice from diet, otherwise serious mental retardation will result.
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Photolysis
|
The process that occurs during the light-dependent reactions in which water is ripped apart to provide electrons to replace those lost by chlorophyll a. Oxygen is released.
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|
Photosynthetic pigments
|
Chemicals that absorb light energy and use it to carry out photosynthesis. Examples are chlorophyll a, chlorophyll b, carotenoids, and phycobilins.
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phycobilins
|
a photosynthetic pigment
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Pinocytosis
|
cellular process by which cells take in large dissolved molecules, referred to as cell drinking.
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|
Pioneer organisms
|
The first to colonize a barren environment in primary ecological succession.
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Pistil
|
Female part of the flower. Each consists of an ovary, stigma, and style. Also called carpel.
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Pith
|
Specialized region in the root of a plant for storage.
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Plasma
|
Liquid portion of the blood.
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Plasmodesmata
|
Openings in cell walls of plants for the passage of materials from one cell to another.
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Plasmolysis
|
Cell shrinking, occurs when a cell is in a hypertonic environment
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Plastids
|
Organelles found only in plant cells; chloroplasts is one example
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Point mutation
|
A mutation in one nucleotide on DNA. Causes sickle cell anemia
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Polarized
|
The condition of an axon of a nerve when it is at rest, also known as resting potential. Sodium and potassium are pumped to opposite sides of the membrane.
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Polygenic
|
There are more than two allelic forms of a gene. The trait exhibit a multitude of variation.
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Polymerase chain reaction
|
A cell-free, automated technique by which a piece of DNA can be rapidly copied or amplified. Useful in genetic engineering.
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Polymers
|
Molecules that are chains of repeating units; proteins and DNA are examples.
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Polyp
|
Vase-shaped body.
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Polypoid
|
An organism with extra sets of chromosomes (3n, 4n, etc). Commonly occurs in plants.
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Polysaccharides
|
Molecules that consist of many monosaccharides joined together. Starch and chitin are examples.
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Population
|
Group of individuals of one species living in one area that have the ability of interbreeding and interacting with each other.
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Primary growth
|
Vertical growth of a plant
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Prions
|
Misfolded proteins that cause mad cow disease
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Prokaryotes
|
Cells that have no internal membranes or internal organelles, like nuclei or mitochondria.
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Prostate gland
|
Large gland that secretes semen directly into the urethra
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Psuedocoelomate
|
An animal with a falce coelom. An example is the roundworm
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Psuedopods
|
Means "false feet." This is how amoeba and white blood cells move from place to place.
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Puberty
|
Onset of the menstruel cycle in girls and sperm production in boys.
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Punctuated equilibrium
|
Theory that proposes that new species appear suddenly after long periods of stasis. Replaced gradualism theory in popularity.
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Purines
|
The nucleotides adenine and guanine.
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Pyloric sphincter
|
Band of muscle at the bottom of the stomach that keeps food in the stomach long enough to be digested.
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|
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Pyramidines
|
Class of nucleotides, includes thymine and cytosine.
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|
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Radioisotopes
|
Radioactive isotopes, those that are decaying as they emit particles from the nucleus.
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Reabsorption
|
In the nephron of the kidneys, a process by which most of the water and solutes (glucose, amino acids, and vitamins) that initially entered the tubule during filtration are transported back into the capillaries, and, thus, back to the body.
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Receptor-mediated endocytosis
|
Process by which cells take in specific molecules for which the cell has a specific receptor.
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|
Recognition sequences
|
(also sites) the specific sites on DNA that restriction enzymes cut.
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Recombinant DNA
|
The modern technique of taking DNA from two sources and combining them into one molecule or cell.
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Redox
|
A combination of reduction and oxidation reactions.
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Reduction
|
Gain of electrons
|
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|
Reduction division
|
another name for meiosis I, the division where homologous pairs separate.
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Regulation
|
Ability to maintain internal stability, homeostasis.
|
|
|
Releaser
|
Sign stimuli exchanged between members of the same species.
|
|
|
Replication bubbles
|
Sections of DNA where the two strands separate in order to enable replication to occur rapidly. There are thousands of these bubbles along the DNA molecule, which speed up the process of replication along the giant human DNA molecule.
|
|
|
Replication fork
|
A Y-shaped region were the new strands of DNA are elongating during DNA replication
|
|
|
Reproduction
|
Ability to generate offspring
|
|
|
Resolution
|
A measure of clarity of an image seen under a microscope
|
|
|
Respiration
|
Metabolic processes that produce energy (ATP) for all the life processes.
|
|
|
Restriction enzymes
|
Extracted from bacteria; they cut DNA at specific recognition sequences or sites, such as GAATTC.
|
|
|
Restriction fragments
|
The fragments of DNA that result from cute made by restriction enzymes.
|
|
|
Rhizobium
|
Symbiotic bacterium that lives in the nodules on roots of specific legumes and that fixes nitrogen gas from the air into a form of nitrogen that te plant requires.
|
|
|
rRNA
|
structural RNA that is synthesized in the nucleolus. Along with proteins, it makes up the ribosome.
|
|
|
Ribosome
|
Structure in cells where proteins are synthesized.
|
|
|
RNA processing
|
Occurs in the nucleus before the newly formed mRNA strand is sent out to the ribosome
|
|
|
Saprobes
|
Organisms that obtain food from decaying organic matter
|
|
|
Sclerenchyma cells
|
plant cells that have very thick primary and secondary cell walls fortified with lignin. Their function is purely support.
|
|
|
Scrotum
|
Sac outside the abdominal cavity that holds the testes.The cooler temperature where enables sperm to survive.
|
|
|
Secondary growth
|
Lateral growth of a plant.
|
|
|
Secretin
|
Digestive hormone that stimulates the pancreas to release bicarbonate to neutralize acid in duodenum.
|
|
|
Secretion
|
Process that occurs in the tubule of the nephron, which is the active, selective uptake of molecules that did not get filtered into Bowman's capsule.
|
|
|
Semiconservative replication
|
The way in which DNA replicates itself. The new DNA molecule consists of one old strand and one new strand.
|
|
|
Sepals
|
Outermost circle of leaves around a flower that are green and closely resemble ordinar leaves.
|
|
|
Serum
|
Plasma without the clotting factors
|
|
|
Sessile
|
Nonmoving
|
|
|
Sex-influenced trait
|
Inheritance is influenced by the sex of the individual carrying the traits.
|
|
|
Sex-linked
|
Traits carried on the X chromosome.
|
|
|
Sieve tube elements
|
Make up phloem, along with companion cells.
|
|
|
Sign stimuli
|
Indicate a FAP
|
|
|
Sinoatrial node
|
Pacemaker of the heart.
|
|
|
Sinuses
|
Cavities in the body for exchange of fluid. Called hemocoels in grasshoppers
|
|
|
Sister chromatids
|
A replicated chromosome consists of two of these, where one is an exact copy of the other.
|
|
|
Spliceosomes
|
Special molecules that assist in the editing of mRNA during RNA processing.
|
|
|
Sodium-potassium pump
|
Elaborate molecule that sits within neuron membranes and pumps sodium and potassium ions across the membrane.
|
|
|
Solute
|
Substance that is dissolved in a solvent
|
|
|
Solvent
|
Substance that does the dissolving.
|
|
|
Somatic system
|
Part of the nervous system that controls voluntary muscles.
|
|
|
Species
|
A population whose members have the potential to interbreed in nature and produce viable, fertile offspring.
|
|
|
Specific heat
|
Amount of heat that must be absorbed in order for 1 gram of a substance to change its temperature by 1º celsius.
|
|
|
Spermatogenesis
|
Formation of sperm by meiotic cell division
|
|
|
Spindle fibers
|
Made of microtubules, these assist in cell division
|
|
|
Spontaneous generation
|
The theory that living things emerge from nonliving or inanimate objects.
|
|
|
Sporophyte
|
The diploid generation of a plant.
|
|
|
Sporopollenin
|
Tough polymer that is resistant to almost all kinds of environmental damage and that protects plants in a harsh terrestrial environment. It is found in the walls of spores and pollen from which it gets its name.
|
|
|
Stabilizing selection
|
This type of natural selection eliminates the extremes and favors the more common intermediate forms.
|
|
|
Stamen
|
Male part of the flower, consists of anther and filament.
|
|
|
Stele
|
Vascular cylinder in a plant root
|
|
|
Stomates
|
Openings in leaves to exchange photosynthetic gases: water vapor, carbon dioxide, and oxygen
|
|
|
Stroma
|
Part of the chloroplasts that holds the grana
|
|
|
Style
|
Long, usually thin stalk of the pistil of a flower
|
|
|
Substrate level phosphorylation
|
Process by which ATP is produced as a special enzyme moves a phosphate from one molecule to ADP. How energy is produced during glycolysis and the Krebs cycle.
|
|
|
Symplast
|
System of transport within a plant consisting of openings in cell walls called plasmodesmata.
|
|
|
Synapsis
|
The process in which homologous chromosomes pair up. This occurs during prophase I.
|
|
|
Synthesis
|
Combining of small molecules or substances into larger, more complex ones
|
|
|
Systole
|
Contraction of the ventricles of the heart. Normal systolic pressure is 120 mm Hg.
|
|
|
Taproot
|
Single, large root like a carrot.
|
|
|
Taxon
|
Levels of organization in out system of classification.
|
|
|
Taxonomy
|
System by which we name and classify all organisms, living and extinct.
|
|
|
Tay-Sachs Disease
|
An inherited disease with onset early in life and that is caused by lack of the enzyme necessary to break down lipids necessary for normal brain function. It is common in Ashkenazi Jews and results in seizures, blindness, and early death.
|
|
|
Telomeres
|
Special nonsense nucleotide sequences (TTAGGG) located at the ends of chromosomes that repeat thousands of times. These ends protect the DNA during cell division.
|
|
|
Territory
|
Area an organism defends and from which other members of the community are excluded.
|
|
|
Testcross
|
Backcross.
|
|
|
Testes
|
Male gonads; the site of sperm formation
|
|
|
Theory of endosymbiosis
|
This theory states that cell organelles, like mitochondria, were once tiny, free-living prokaryotic organisms that took up permanent residence inside larger prokaryotic organisms.
|
|
|
Thermophiles
|
Organisms that thrive in very high temperatures.
|
|
|
Thrombocytes
|
platelets
|
|
|
Thylakoids
|
Specialized membranes that make up the grana in chloroplasts, the site of the light-dependent reactions.
|
|
|
Tracer
|
Radioactive substance that can be used to track a substance as it moves through an organism or through a metabolic pathway. Can be used in research or as a diagnostic tool in medicine.
|
|
|
Tracheids
|
Cells that, along with vessel elements, make up xylem.
|
|
|
Transcription
|
the process by which DNA makes RNA.
|
|
|
tRNA
|
Shaped like a cloverleaf and carries amino acids to the mRNA at the ribosome as proteins are synthesized.
|
|
|
Transformation
|
A phenomenon in bacteria. They have the ability to transform themselves by transferring genetic factors from one bacteria cell to another.
|
|
|
Translation
|
The process in which the DNA code is translated into an amino acid sequence and a polypeptide is formed. Occurs as the ribosome.
|
|
|
Translocation
|
A fragment of a chromosome becomes attached to a nonhomologous chromosome.
|
|
|
Transpiration
|
Loss of water from a leaf of a plant through stomates.
|
|
|
Transport
|
Intake and distribution of substances in cells or tissue; not the came thing as locomotion
|
|
|
Trichomes
|
Tiny, spikelike projections on some leaves for protection
|
|
|
Triploblastic
|
an animal consisting of three cell layers. This includes every animal more sophisticated than a flatworm.
|
|
|
Trisomy
|
Having a chromosome in triplicate instead of duplicate. Down syndrome is caused by this of the 21st chromosome.
|
|
|
Tropic hormones
|
Hormones that stimulate other glands to release their hormones.
|
|
|
Tropism
|
Growth of a plant toward or away from a stimulus
|
|
|
Turgid
|
A property of plant cells, swollen
|
|
|
Turgor pressure
|
Pressure exerted when a plant cell swells
|
|
|
Ultracentrifuge
|
A machine that spins mashed tissue so quickly that it separates the homogenate into separate pellets of different organelles.
|
|
|
Urethra
|
Tube that carries semen and urine in males. In females, it carries only urine.
|
|
|
Uterus
|
Where the blastula stage of the embryo implants and develops during the nine-month gestation if fertilization occurs.
|
|
|
Vacuoles
|
Organelles in cells whose function is storage
|
|
|
Vagina
|
Birth canal
|
|
|
Vas deferens
|
Duct that carries sperm during ejaculation from the testes to the penis.
|
|
|
Vegetative propagation
|
Asexual reproduction in a plant where a piece of the root, stem, or lead produces an entirely new plant genetically identical to the parent plant. Examples are grafting, cuttings, bulbs, and runners.
|
|
|
Vesicles
|
small vacuoles
|
|
|
Vessel elements
|
Structures that, along with tracheids, make up xylem
|
|
|
Vestigial structures
|
Structures that are remnants of an earlier active structure, such as the appendix.
|
|
|
Villus
|
Millions of fingerlike projections that line the small intestine and absorb all nutrients that were previously released from digested food.
|
|
|
Visible spectrum
|
Wavelengths of light that humans can see: 380 nm to 750 nm.
|
|
|
Wave of depolarization
|
The condition of an axon when an impulse is passing, also referred to as an action potential.
|
|
|
Xylem |
Vessels in plants that carry water and nutrients from the soil to the rest of the plant. |
|
|
Yolk sac
|
Membrane that encloses the yolk of an egg; food for the growing embryo. |
