Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

image

Play button

image

Play button

image

Progress

1/324

Click to flip

324 Cards in this Set

  • Front
  • Back
Properties of Water
Excellent solvent, high heat capacity, ice is less dense, strong cohesion and high surface tension, high adhesion
Hydrophilic
Dissolves in water. Polar or ionic
Hydrophobic
Does not dissolve in water. Nonpolar or covalent
Heat Capacity
The degree to which a substance changes temperature as a result of gaining or losing energy in the form of heat. Large bodies of water thus have very stable temperatures.
Macromolecules
Large molecules consisting of hundreds to thousands of atoms
Hydroxyl Group
-OH, alcohols
Carboxyl Group
-COOH, carboxylic acids
Amino Group
-NH2, amines
Phosphate
-PO4, organic phosphates
Carbonyl
-CO, ketones, aldehydes
Methyl
-CH3, no class name
Carbohydrates
Sugar macromolecules
Monosaccharide
The simplest form of carbohydrate, made up of a single sugar molecule. Includes fructose and glucose.
Disaccharide
Two monosaccharides joined through a glycosidic linkage. Includes sucrose, lactose, and maltose.
Dehydration Reaction
A reaction such as the synthesis of a disaccharide in which a single water molecule is lost.
Polysaccharide
A polymer of many monosaccharides, includes starch, glycogen, cellulose, and chitin.
Starch
Polymer of alpha glucose. The principle energy storage molecule in plant cells.
Glycogen
Polymer of alpha glucose. A major energy sotrage molecule in animal cells.
Cellulose
Polymer of beta glucose. A structural molecule in the walls of plant cells.
Chitin
A polymer of beta glucose. A structural molecule in the walls of fungus cells and in the exoskeletons of insects, arthopods, and mollusks.
Lipids
Macromolecules which are insoluble in water, but soluble in nonpolar substances, including triglycerides, phospholipids, and steroids.
Triglycerides
Includes fats, oils, and waxes. Made up of three fatty acids attached to a glycerol molecule.
Saturated Fatty Acid
A fatty acid with only single bonds
Monounsaturated Fatty Acid
A fatty acid with a single double bond
Polyunsaturated Fatty Acid
A fatty acid with multiple double bonds.
Phospholipids
A lipid structurally similar to a triglyceride except that one of the fatty acids is replaced with a phosphate group, which is hydrophilic.
Amphipathic
Molecules with both hydrophilic and hydrophobic ends.
Steroids
Lipids made up of four linked carbon rings. Examples include cholesterol and certain hormones.
Proteins
A type of macromolecule which is made up of many amino acids linked through peptide bonds.
Primary Structure
The order of amino acids in a protein.
Secondary Structure
The 3-D shape that results from hydrogen bonding between amino and carboxyl groups of adjacent amino acids.
Alpha Helix
A spiral shaped protein resulting from hydrogen bonding in the secondary structure.
Beta Pleated Sheet
A folded plane shaped protein resulting from hydrogen bonding in the secondary structure.
Tertiary Structure
Three dimensional structure of a protein resulting from hydrogen bonding, ionic bonding, the hydrophobic effect, and disulfide bonds.
Hydrophobic Effect
The effect on the tertiary structure of proteins when hydrophobic R groups move toward the center of a protein and away from the water.
Disulfide Bonds
Bonds between the sulfur atoms in cysteines, affecting the tertiary structure of a protein.
Quarternary Structure
A protein made from two or more peptide chains.
DNA Nucleotide
The monomer of nucleic acids, made up of a nitrogen base, deoxyribose (a five carbon sugar), and a phosphate group.
Antiparallel
The way in which the two strands of DNA are arranged, that is, the 5' and 3' ends are opposite
Enzyme
A globular protein which acts as a catalyst of metabolic reactions. Each substrate is specific to a specific substrate
Substrate
The substance on which an enzyme acts.
Induced Fit Model
Each protein has an active site, where the reactants fit. The reactants form the enzyme to change shape into a position which increases the rate of the reaction.
Cofactors
Nonprotein molecules which assist enzymes.
Holoenzyme
The union of a cofactor and an enzyme
Coenzyme
Organic cofactors, which assist in the reactions.
Inorganic Cofactors
Are often metal ions, and also assist in the reactions.
Allosteric Enzymes
Enzymes with two bonding sites, one as the active site and one for an allosteric effector
Allosteric Activator
A substance that binds to an allosteric enzyme and induces the active form of the enzyme.
Allosteric Inhibitor
A substance that binds to an allosteric enzyme and induces the inactive form of the enzyme.
Feedback Inhibition
When the end product of a series of metabolic reactions acts as an allosteric inhibitor in order to end the reaction series.
Competitive Inhibition
When a substance mimics a substrate and binds to the active site of an enzyme, thus preventing any catalyzation from occuring.
Noncompetitor Inhibitor
A substance that binds to an enzyme somewhere besides the active site, changing its shape so that it cannot work.
Cooperativity
When an enzyme with multiple active sites becomes more receptive after one of its sites has been filled.
Cytosol
The fluid matrix in which the organelles of a cell are suspended
Peripheral Proteins
Proteins which attach to either the inner or outer surface of a phospholipid bilayer.
Integral Proteins
Proteins which extend through one surface of a phospholipid bilayer; are amphipathic
Transmembrane Proteins
Proteins which extend all the way through both ends of a phospholipid bilayer.
Phospholipid Membrane
A selectively permeable membrane which only allows small, uncharged, polar molecules, hydrophobic molecules, and lipid-soluble molecules to pass through
Channel Proteins
Provide passageways through a membrane for hydrophilic substances
Transport Proteins
Use ATP to actively transport substances across a membrane.
Recognition Proteins
Distingiush the identity of neighboring cells. Have short polysaccharide chains attached, which stick out from the surface of the cell.
Glycoproteins
Proteins with polysaccharide chains attached.
Adhesion Proteins
Proteins which attach to neighboring cells.
Receptor Proteins
Provide binding sites for hormornes or other similar molecules.
Electron Transfer Proteins
Transfer electrons from one molecule to another during redox reactions.
Cholesterol
Is distributed throughout phospholipid bilayers to provide rigidity in animal cells.
Sterols
Provide rigidity to plant phospholipid bilayers.
Glycocalyx
The collective group of oligosaccharides attached to glycoproteins, which provide for cell to cell recognition.
Chromatin
Threads of DNA, the state which it exists during interphase
Nucleosomes
Bundles of DNA coiled around histones
Ribosomes
The centers for production of proteins
Rough Endoplasmic Reticulum
Creates glycoproteins
Smooth Endoplasmic Reticulum
Synthesizes various lipids and hormones. Breaks down toxins and drugs in liver cells.
Golgi Apparatus
Modify and package proteins and lipids into vesicles
Vesicles
Small spherical sacs which originate at the Golgi Apparatus and release their contents outside the cell by merging with the membrane.
Lysosomes
Special vesicles which contain digestive enzymes; they break down food, cellular debris, and bacteria. Only seen in animal cells.
Peroxisomes
Break down hydrogen peroxide to water.
Microtubules
Part of the cytoskeleton; made of tubulin; provides support and motility; found in the spindle apparatus and in flagella and cilia
Intermediate Filaments
Part of the cytoskeleton; provide support for maintaining the shape of a cell.
Microfilaments
Part of the cytoskeleton; made of actin; involved with cell motility; found in muscle cells and other cells which often move
Centrioles
Act as microtubule organizing centers; a pair of them are located outside the nuclear envelope and create the spindle apparatus.
Basal Bodies
Act as microtubule organizing centers at the base of cilia and flagella
Cell Walls
Only found in plants, fungi, protists, and bacteria; made from cellulose in plants and chitin in fungi
Transport vesicles
Move substances between organelles or from the interior to exterior of a cell
Food vacuoles
Temporary nutrient storage sites; often merge with lysosomes to break down food
Storage vacuoles
Only found in plants; store starch, pigments, and toxins
Central Vacuoles
Large bodies which make up most of the interior of plant cells, when filled with water they exert turgor on the cell walls to maintain rigidity
Turgor
Pressure exerted on plant cell walls by a full central vacuole
Contractile Vacuoles
Organelles in single-celled organisms which pump water in and out of the cell.
Cell Junctions
Organelles which connect cells to each other or provide passageways for cellular exchange
Desmosomes
Proteins which attach animal cells to each other
Tight Junctions
Tight seals between animal cells, which completely encircles each cell.
Gap Junctions
Narrow tunnels between animal cells made up of connexons; ions and small molecules are allowed to pass but not the cytoplasm
Plasmodesmata
Narrow tunnels between plant cells. A tube of ER called a desmotubule passes through the opening
Characteristics of Plant Cells
Cell walls, chloroplasts, central vacuoles; no lysosomes or centrioles
Characteristics of Prokaryotes
No nucleus, one single DNA molecule, smaller ribosomes, cell walls made from peptidoglycans, flagella not made from microtubules
Hypertonic
Higher concentration of solutes
Hypotonic
Lower concentration of solutes
Isotonic
Equal concentration of solutes
Bulk Flow
The collective movement of substances in the same direction due to some force or pressure.
Passive Transport
The movement of substances down their concentration gradient
Dialysis
The diffusion of solutes across a selectively permeable membrane.
Plasmolysis
The movement of water out of a cell, resulting in the cells collapse.
Facilitated Diffusion
The diffusion of solutes through channel proteins.
Countercurrent Exchange
The diffusion of substances where bulk flow is occuring in opposite directions
Active Transport
The movement of solutes against the concentration gradient, requiring the expentidure of energy.
Vesicular Transport
The use of vesicles to move larger particles across the plasma membrane.
Exocytosis
A type of vesicular transport in which the vesicles fuse with the plasma membrane and release their contents to the outside of the cell.
Endocytosis
A type of vesicular transport in which the plasma membrane engulfs a particle outside of the cell.
Phagocytosis
Type of endocytosis in which undissolved material enters the cell. The membrane wraps around the material, forming a vesicle.
Pinocytosis
Type of endocytosis, where dissolved substances enter the cell; the membrane folds inward to form a channel into the cell.
Receptor-mediated Endocytosis
A type of endocytosis, in which specific molecules outside of the cell bind of receptors on the plasma membrane. The receptors fold inward to form a vesicle.
Population
A group of all the same species living in one area.
Community
A group of populations in one area.
Ecosystem
The relationships between the organisms in a community and the physical environment.
Biosphere
All of Earth which contains life; including the upper soil, the lower atmosphere, and bodies of water.
Habitat
The type of place in which an organism inhabits; including other organisms in hte area and physical and chemical characteristics
Niche
All the biotic and abiotic resources in an envrionment used by an organism
Population Size
Represented by "N", the total number of individuals in a population
Density
Total number of individuals per area or volume
Dispersion
The way in which a population is distributed; can be clumped, uniform, or random
Biotic Potential
The maximum growth rate of a population under perfectly ideal conditions, with unlimited resources and no growth restrictions
Carrying Capacity
The maximum population size that can be sustained by a certain habitat
Limiting Factors
Elements which prevent a population from reaching its biotic potential
Density Dependent Factors
Elements, such as resouces, whose limiting effect on a population increases proportionally to the size of the population
Density Independent Factors
Limiting factors which are not affected by population size, such as natural disasters and climate extremes.
Growth Rate Equation
(Births - Deaths)/N

N=initial population
Intrinsic Rate
The maximum reproductive rate of a population
Logistic Growth
Occurs when limiting factors create a carrying capacity, resulting in an S shaped curve.
R-selected Species
Species which exhibit exponential growth; most are opportunistic, produce many offspring and mature quickly
K-selected Species
Species whose populations remain relatively constant around the carrying capacity (K); most produce few, large offspring which require parental care
Human Exponential Growth Factors
Manmade increases in food supply, medicines, reduction in waste, expansion of habitat
Interspecific Competition
Competition between different species
Competitive Exclusion Principle
Also called Gause's Principle, it states that when two species are competing for exactly the same resources, one will outcompete the other, which will be eliminated eventually
Resource Partitioning
A way in which multiple species can coexist in the same habitat, by using up different resources.
Character Displacement
A result of resource partitioning, natural selection of characteristics which allow a population to obtain resources in their partition occurs, reducing competition
Realized Niche
The niche in which an organism inhabits when other competitors are present
Fundamental Niche
The niche in which an organism inhabits when no competing species are present
True Predator
An organism which kills and eats another animal.
Parasitoid
An insect which lays its eggs on or in a host, when the eggs hatch the larvae consume the tissues of the host for nourishment
Granivores
Herbivores which eat an entire organism, similar to predators
Grazers
Herbivores which eat grasses.
Browsers
Herbivores which eat the leaves of plants
Mutualism
A type of symbiosis in which both species benefit
Commensalism
A type of symbiosis in which one species benefits and the other is not affected at all
Parasitism
A type of symbiosis in which one species benefits and the other is harmed
Coevolution
The evolution of one species in response to evolution in another
Secondary Compounds
Toxic chemicals produced in plants which discourage herbivores
Cyrptic Coloration
Camoflage which allows an organism to blend in with its surroundings.
Aposematic Coloration
Patterns or colors which warn predators that an organism should be avoided
Mullerian Mimicry
When several animals with the same defense mechanism share the same aposematic coloration, so that it is easier for predators to learn.
Batesian Mimicry
When an animal with no defense mechanism mimics the coloration or pattern of one woh does
Ecological Succession
The change in how the populations which make up a community change in composition over time, eventually resulting in a climax community
Climax Community
The final state in ecological succession
Pioneer Species
The first species to colonize a new habitat; usually r-selected species
Primary Succession
Succession on habitats which originally had not supported life
Secondary Succession
Succession originating in a habitat whose communities were destroyed by an event
Trophic Levels
The main energy source of an organism
Primary Producers
Autotrophs which convert the suns energy into chemical energy; includes plants, photosynthetic protists, cyanobacteria, and chemosynthetic bacteria. They are eaten by primary conusmers
Detritivores
Consumers which obtain their energy from dead plants and animals. The smallest are called decomposers
Ecological Efficiency
The amount of energy transferred from one trophic level to the next, usually around 10%
Hydrologic Cycle
The water cycle: kept in oceans, air, groundwater, and glaciers; plants absorb water and animals drink water or eat other organisms; plants transpire and animals decompose
Carbon Cycle
kept in the atmosphere, fossil fuels, peat, and organic matter; plants use carbon dioxide, animals consume plants or other animals; when organic matter is burned or organisms release carbon dioxide
Nitrogen Cycle
kept in the atmosphere and soil; plants abosrb nitrogen, animals eat plants or other animals, baceteria concert nitrate to nitrogen, animals excete ammonia
Nitrogen Fixation
Nitrogen converted to ammonia by prokaryotes; nitrogen converted to nitrate by lightning and UV radiation
Nitrification
Ammonium converted to nitrite and nitrite converted to nitrate by various bacteria
Phosphorus Cycle
kept in rocks, plants absorb phosphate from soil; animals eat plants or other animals; released in decomposition or animal waste
Biomes
Regions of the biosphere that exhibit common environmental characteristics
Tropical Rain Forests
High temperature and rainfall. Canopy of tall trees. Many vines and epiphytes.
Epiphytes
Plants which live on other plants commensally
Savannas
Grasslands with a few scattered trees. High temperatures but less water than rain forests
Temperate Grasslands
Less rainfall and lower temperatures than savannas
Temperate Deciduous Forests
Warm summers, cold winters, moderate precipitation
Deserts
Hot, dry; plants only grow in short periods following rainfall; animals have thick skin, and conserve water
Taigas
Coniferous forests; cold winters; more snow than rain
Tundras
Very cold winters; permafrost remains frozen throughout the year
Epithelial Tissue
Animal tissue which includes outer skin lahyers and internal protective coverings
Connective Tissue
Animal tissue including bone, cartilage, and blood
Homeostasis
The maitenance of stable internal conditions
Negative Feedback
The way in which animals maintain homeostatis, with a receptor detecting when conditions are unfavorable, an integrator evaluates the change and activates an effector to correct it.
Integrator
A control center which evaluates changes from homeostasis detected by receptors and actives an effector.
Effector
A mechanism which corrects changes from homeostasis
Ectotherms
Animals which obtain body heat from their environment, also called poikilotherms, include most invertebrates, amphibians, reptiles, and fish
Poikilotherms
Cold blooded animals, also called ectotherms
Endotherms
Animals which generate their own heat
Homoeotherms
Warm blooded animals, also called endotherms
Methods of Thermoregulation
Cooling by evaporation, warming by metabolism, adjusting surface area
Respiration
The movement of gases into and out of an organism
Methods of Respiration
Direct contact with the environment, gills, tracheae, and lungs
Gills
Outgrowths from the body which create a large surface area on which gas exchange can occur
Operculum
The cover for gills
Tracheae
Chitin-lined tubes in which respiration occurs
Spiracles
Openings in which oxygen enters tracheae and carbon dioxide exits
Epiglottis
A flap covering the human trachea
Bronchi
Tubes which enter the lungs, branching out from the trachea
Bronchioles
Narrower tubes which branch out from the bronchi
Alveolus
A small sac at the end of each bronciole, oxygen diffused from here into the blood stream
Diaphragm
A muslce under the lungs which increases the volume of the lungs by contracting
Intercostal Muscles
Muscles between the ribs, which contract to expand the lungs
Open Circulatory System
Blood is pumped into a cavity called a hemocoel, where it is bathed in a nutrient rich fluid called hemolymph.
Hemolymph
Nutrient carrying fluid which bathes blood in open circulatory systems
Hemocoel
A cavity in open circulatory systems where blood is bathed in nutrient and oxygen rich hemolymph
Ostia
Holes which allow hemolymph to return to the heart
Closed Circulatory System
A system in which blood is confined to the heart and vessels
Arteries
Blood vessels moving away from the heart in a closed circulatory system
Arterioles
Smaller vessels which the arteries branch into
Capillaries
The smallest of arteries; gas and nutrients are diffused from the capillaries to other cells
Veins
Blood vessels returning to the heart with deoxygenated blood
Venules
Smaller blood vessels, which merge into veins
Pulmonary Circuit
Path through the heart: right atrium, right ventricle, left atrium, left ventricle
Erthrocytes
Red blood cells
Leukocytes
White blood cells
Platelets
Cell fragments which aid in blood clotting
Plasma
The liquid portion of blood
Primary Sex Characteristics
Structures in males or females directly involved in reproduction
Secondary Sex Characteristics
Structures such as body hair which are a result of gender but not directly involved with reproduction
Ovary
The organ where ova, or eggs, are produced
Oviduct
Also called the Fallopian Tube, transfers eggs from the ovary to the uterus
Uterus
The site for embryonic development
Endometrium
The inside wall of the uterus
Vagina
The pathway from the uterus out of the body
Cervix
An opening from the uterus to the vagina.
Seminferous Tubules
The sites for the production of sperm
Interstitual Cells
Produce male sex hormones
Epididymis
A coiled tube which acts as the site for final maturation and storage of sperm
Vas deferens
Transfers sperm from the epididymis to the urethra
Seminal Vesicles
Secrete mucus, fructose, and prostaglandins into the sperm during ejaculation
Prostate gland
Secretes a fluid into the urethra which neutralizes the acidity of any lingering urine
Acrosome
A lysosome at the tip of the sperm head with enzymes used to penetrate the egg
Midpiece (of sperm)
The first part of the flagellum, which contains mitochondria which supply ATP for flagellar movement
Gametogenesis
The meiotic cell divisions which result in gametes
Oogenesis
The development of ova, which begins during embryonic development, but is halted until puberty is reached. While two gametes are created, only one develops into an egg.
Oogonia
Fetal cells which divide to produce primary oocytes during oogenesis
Secondary Oocyte
The oocyte which develops into an egg
Polar Body
The oocyte which recieves little cytoplasm and eventually dies
Follicle
An envelope of cells surrounding a developing oocyte
Spermatogensis
The creation of sperm through meiosis; begins at puberty
Spermatids
The four gametes which result from spermatogenesis and mature into sperm
Menstrual Cycle
The thicking of the endometrium of the uterus in preparation for implantation of an fertilized egg and the shedding of the endometrium if implanatation
Ovarian Cycle
Development of the egg, release of it, and secretion of estrogen and progesterone from the corpus luteum after ovulation
Androgens
Male sex hormones
Fetus
An embryo which resembles the infant form of an animal
Fertilization
When a sperm penetrates the plasma membrane of a secondary oocyte
Recognition (fertilization)
During fertilization, the sperm secretes a protein which binds to specific receptor molecules on the secondary oocyte, ensuring that fertilization only occurs between members of the same species
Cleavage Divisions
After fertilization, the newly formed zygote undergoes many rapid cell divisions without increasing in size
Blastomeres
Cells that result from cleavage division, each generation contains less cytoplasm than the former
Morula
A solid ball of blasomeres that results from many cleavage division
Blastula
A hollow sphere of cells which results from liquid filling the inside of a morula
Blastocoel
The liquid cavity of a blastula
Gastrula
A two layered embryo that results from cells moving into the blastocoel of a blastula during embryonic development
Blastopore
The opening into an archenteron in a gastrula
Amniotes
Birds, reptiles, and humans.
Organogenesis
The development of specific tissues and organs
Nephrons
Filtering tubes which make up the kidneys of vertebrates.
Renal Pelvis
The center of the kidney, which drains into the ureter and then into the bladder.
Urea
The liver converts the toxic ammonia into urea, which is excreted through urine
Salivary Amylase
An enzyme secreted by the salivary glands in the mouth which begins breaking down starch into maltose.
Peristalsis
Muscular contractions which move food through the esophagus
Gastric Juice
Mixture of digestive enzymes and HCl secreted by the stomach; mixes with food and water to produce chyme
Chyme
A mixture of gastric juice, food, and water
Pepsin
An enzyme which chemically breaks down proteins
Pyloric Sphincter
A valve at the end of the stomach which regulates the movement of chyme into the small intestine
Duodenum
The first 25 cm of the small intestine which continues breakdown of food
Pancreas
produces enzymes for digestion
Liver
Produces bile, which breaks up fat into smaller droplets, increasing surface area.
Gall-Bladder
Where bile is stored
Villi
Fingerlike projections on the wall of the small intestines, which serve to increase surface and absorbtion
Large Intestine
Reabsorbs water in order to form solid waste, or feces
Stroma
The fluid contained in chloroplasts
Thylakoids
Individual membrane layers which contain light absorbing pigments for light dependent reactions in chloroplasts
Grana
Stacks of thylakoids
ATP Synthases
Channel proteins which allow protons to flow from thylakoid membranes to the stroma, generating energy for the phosphorlyation of ATP
Photorespiration
The fixation of oxygen that occurs alongside photosynthesis and makes photosynthesis less efficient
C4 Photosynthesis
An improvement upon standard photosynthesis in which CO2 is moved from mesophyll cells to bundle sheath cells. Because little oxygen reaches the bundle sheath cells, it is more efficient, and the stomata do not need to stay open as long, reducing H2O loss.
CAM
An improvement to C3 photosynthesis, in which CO2 is accumlated at night, and then fixed during the day, reducing water loss.
Aerobic Respiration
Respiration in the presence of oxygen: divided into glycolysis, the Krebs cycle, and oxidative phosphorylation
Glycolysis
The decomposition of glucose into pyruvate during respirationn. 1 glucose is converted into 2 pyruvate, 2 NADH, and 2 ATP
Krebs Cycle
Converts pyruvate to 3 NADH, 1 FADH, 1 ATP, and CO2
Oxidative Phosphorylation
The process of extracting ATP from NADH and FADH
Matrix
The fluid part of a mitochondria, where the Kreb's cycle occurs.
Cristae
The membranes which separate the matrix of a mitochondria from the outer compartment
Alcoholic Fermentation
Occurs in plants, fungi, and bacteria in the absence of oxygen. Frees up NAD+ to be used by glycolysis, only creates 2 ATP, as well as ethanol
Lactate Fermentation
Occurs in animals, frees up NAD+ for use by glycolysis by converting pyruvate to lactic acid (lactate)
Interphase
The time period between cell divisions. Nucleoli are visible, two MTOCs lie next to each other
Prophase
Nucleoli disappear, chromatin condenses into chromosomes, nuclear envelope breaks down, mitotic spindle is assembled as MTOCs move to poles of the nulceus, microtubules attach to a kinetochore on each centromere
Metaphase
Chromosomes distribute themselves across the metaphase plate, and ends when the chromosomes are pulled apart into two chromatids
Anaphase
microtubules connected to the chromosomes shorten, pulling them to opposite pole
Telophase
A nuclear envelope develops around each pole, the chromosomes disperse into chromatin, and nucleoli reappear. Cytokinesis occurs simultaneously
Cleavage Furrow
The groove that forms between forming daughter cells during cytokinesis.
Cell Plate
A collection of vesicles which forms between daughter cells of newly formed plant cells and becomes the plasma membranes
Synapsis
The process of homologous chromosomes pairing up
Tetrads
Pairs of homologous chromosomes
Chiasmata
Sites where genetic material is exchanges between nonsister homologous chromomes in crossing over
Incomplete Dominance
When the dominant and recessive alleles blend to create a mix, such as red and white into pink.
Codominance
When both alleles are expressed completely.
Multiple Alleles
When more than two alleles are present, such as with blood type
Epistasis
When one gene effects the phenotypic expression of a second gene.
Pleiotropy
When a single gene has more than one phenotypic expression
Polygenic Inheritance
When a range of phenotypic expressions is possible, such as with height in humans
Linked Genes
Genes loacted on the same chromosome, and which cannot segregate independently. Most of the time they are inherited together, unless crossing over occurs. The chance of this depends on how far apart the genes are located on the chromosomes.
Nondisjunction
When chromsomes do not properly separate during metaphase of meiosis, and both homologous chromosomes go to one pole.
Deletion
When a portion of a chromosome has been deleted
Duplication
When a portion of a chromosome is duplicated
Translocation
When a portion of a chromosome is moved to another chromosome
Inversion
When a portion of a chromosome is attached in a reversed orientation to the same chromosome
Semiconservative Replication
Each new DNA strand is made up of one original strand and one newly synthesized one.
Helicase
An enzyme which unwinds the DNA helix, forming a replication fork
Topoisomerases
A group of enzymes which break and rejoin the double ehlix in preparation for duplication
DNA Polymerase
The enzyme which assembles new DNA strands
Leading Strand
The complement to the 3'->5' strand of existing DNA, which can be synthesized easily
Okazaki Segments
Pieces of newly synthesized DNA which form the laggin strand, and must be connected with DNA ligase
DNA Ligase
The enzyme which connects Okazaki segements
Lagging Strand
The complement to the 5'->3' strand of existing DNA, which must be synthesized in fragments
RNA Primase
Because DNA polymerase can only work on an existing strand, the new strands are started by RNA nucleotides with the assistance of RNA primase, and later switched
Mismatch Repair
The fixing of newly formed DNA by proofreading enzymes
Excision Repair
The fixing of mistakes in DNA replication by splicing out the anomolies and using the complementary strand as a template
Frameshift Mutation
A mutation in which an additional nucleotide is added, displacing every following nucleotide as well
Mutagens
Radiation or chemicals which cause mutations
Carcinogens
Mutagens which trigger cancer
Dendrite
An extension from the nerve cell body which receives stimuli
Axon
An extension from the nerve cell which sends nerve impulses
Sensory neurons
Neurons which receive stimuli, then transmit them to motor neurons by way of association neurons
Motor nuerons
Nuerons which, after recieving a signal from association neurons, produce some sort of response
Association neurons
Nuerons which transmit signals from sensory neurons to motor neurons