Biology EOC Review

activation energy

energy needed to start a chemical reaction; lowered by enzymes

active transport

movement of molecules across a membrane requiring energy to be expended by the cell

adaptation

inherited characteristic that increases an organism's chance of survival

allele

the different forms of a gene; could be dominant or recessive

amino acid

basic building blocks of proteins

analogous structures

structures that do not have a common evolutionary origin but are similar in form or function

anaphase

the third phase of mitosis, during which the chromosome pairs separate and move toward opposite poles

antibiotic

compound that blocks the growth and reproduction of bacteria

antibody

a substance produced by the body that destroys or inactivates a pathogen that has entered the body

antigen

substance (usually foreign) that stimulates the production of an antibody

archaea

domain of unicellular prokaryotes that have cell walls that do not contain peptidoglycan

ATP

a nucleotide that stores and transfers energy within cells

autotroph

organism that can capture energy from sunlight or chemicals and use it to produce its own food; also called a producer

bacteria

domain of unicellular prokaryotes that have cell walls containing peptidoglycans

bacteriophage

virus that infects bacteria

base deletion

mutation which results in the loss of nucleotide pairs in a gene; have a major effect on the resulting protein

base insertion

mutation which results in the addition of nucleotide pairs in a gene; have a major effect on the resulting protein

base-pair substitution

a type of point mutation where one nucleotide and its partner are replaced by another pair of nucleotides

behavioral adaptation

an inherited behavior that helps an organism survive; like escaping from predators or find a mate

binary fission

asexual reproduction in prokaryotes by which one cell divides into two identical cells

fetus

an unborn or unhatched vertebrate in the later stages of development showing the main recognizable features of the mature animal

fever

a rise in the temperature of the body

fitness

the ability of an individual to survive and reproduce in its specific environment

food chain

a series of steps in which organisms transfer energy by eating and being eaten

food web

a diagram that shows the feeding relationships between organisms in an ecosystem

fossil

the remains (or an impression) of a plant or animal that existed in a past geological age and that has been excavated from the soil

gamete

egg or sperm sex cell that contains a single set of chromosomes (haploid), one from each homologous pair

gene

sequence of DNA that codes for a protein and thus determines a trait

binomial nomenclature

Classification system in which each species is assigned a two-part scientific name including the genus and species

biodiversity

the variety of different species in a given area

biogeochemical cycle

process in which elements, chemical compounds, and other forms of matter are passed from one organism to another and from one part of the biosphere to another; like the carbon and nitrogen cycle

biomass

the total amount of living matter within a given trophic level

capsid

the outer covering of protein surrounding the nucleic acid of a virus

carbohydrate

organic compound used by cells to store and release energy; composed of carbon, hydrogen, and oxygen

carbon cycle

the organic circulation of carbon from the atmosphere into organisms and back again

carnivore

a consumer that only eats other consumers

catalyst

substance that speeds up the rate of a chemical reaction; like an enzyme

cell

basic unit of life

cell cycle

the cycle of growth and reproduction of a cell, consisting of interphase (g1, s, g2) and mitosis (division of the nucleus-prophase, metaphase, anaphase, and telophase) and cytokinesis (division of cytoplasm)

cell division

the process by which a cell divides into two new daughter cells

cell membrane

The lipid bilayer that forms the outer boundary of the cell

cell wall

a rigid structure that surrounds the cell membrane and provides support to the cell; made of carbohydrates

cellular respiration

process that releases energy by breaking down glucose and other food molecules in the presence of oxygen

centriole

organize the spindle fibers to separate chromosomes during animal cell mitosis

centromere

area where the chromatids of a chromosome are attached

chlorophyll

green pigment in plants that absorbs light energy used to carry out photosynthesis

chloroplast

organelle found in cells of plants and some other organisms that captures the energy from sunlight and converts it into chemical energy

chromatid

one of two identical "sister" parts of a duplicated chromosome

gradualism

a model of evolution in which gradual change over a long period of time leads to biological diversity

guard cell

Pairs of cells that surround stomata and control their opening and closing.

habitat

the place where an organism lives

haploid number

half the normal number of chromosomes; found in sex cells

herbivore

consumer that eats only producers; also called a primary consumer

heterozygous

having two different alleles for a trait

homeostasis

process by which organisms maintain a relatively stable internal environment

chromosome

condensed threads of genetic material formed from chromatin as a cell prepares to divide

climax community

a relatively stable long-lasting community reached in a successional series

codon

in RNA, a three-base "word" that codes for one amino acid

commensalism

symbiotic relationship in which one member of the association benefits and the other is neither helped nor harmed

competition

the struggle between organisms to survive in a habitat with limited resources

concentration gradient

difference in concentration of a substance on two sides of a membrane

conclusion

a summary of what you have learned from an experiment

consumer

an organism that obtains energy by feeding on other organisms

crossing over

exchange of genetic material between homologous chromosomes during prophase I of meiosis

cytokinesis

division of the cytoplasm

cytoplasm

a jellylike fluid inside the cell in which the organelles are suspended

data

information gathered from observations

decomposer

organism that breaks down and obtains energy from dead organic matter

deforestation

the removal of trees

differentiation

process in which cells become specialized in structure and function

diffusion

the process by which molecules move from an area of higher concentration to an area of lower concentration; passive

dihybrid cross

genetic cross using two traits with two alleles each

diploid number

cell condition in which two of each type of chromosome are present

disturbance

A discrete event that disrupts an ecosystem or community. Examples of natural disturbances include fires, hurricanes, tornadoes, droughts, and floods. Examples of human-caused disturbances include deforestation, overgrazing, and plowing.

DNA

deoxyribonucleic acid, the material that contains the information that determines inherited characteristics

kingdom

large taxonomic group, consisting of closely related phyla

learned behavior

a behavior an animal learns from its parents

lipid

macromolecule made mainly from carbon and hydrogen atoms; includes fats, oils, and waxes

lysosome

cell organelle filled with enzymes needed to break down certain materials in the cell

macromolecule

any large complex organic molecule

meiosis

Cell division that produces reproductive cells in sexually reproducing organisms

mRNA

messenger RNA; type of RNA that carries instructions from DNA in the nucleus to the ribosome

metaphase

second phase of mitosis, during which the chromosomes line up across the center of the cell

domain

Most inclusive taxonomic category; larger than a kingdom

dominant

trait that will show up in an organism's phenotype if gene is present

double helix

two strands of nucleotides wound about each other; structure of DNA

ecological succession

gradual change in living communities that follows a disturbance

ecosystem

living and nonliving things in an environment, together with their interactions

egg

Female sex cell

embryo

organism in its early stage of development

embryology

study of multicellular organisms as they develop from fertilized eggs to fully formed organisms

endocytosis

process by which a cell takes in a substance by surrounding it with the cell membrane; active transport

endoplasmic reticulum

a system of membranes that is found in a cell's cytoplasm and that assists in the production, processing, and transport of proteins and in the production of lipids

energy pyramid

a diagram that shows the amount of energy that moves from one feeding level to another in a food web

enzyme

protein that speeds up a chemical reaction

equilibrium

When the concentration of a solute is the same throughout a solution

eukaryote

A cell that contains a nucleus and membrane bound organelles

eutrophication

rapid growth of algae in bodies of water, due to high levels of nitrogen and often phosphate

evolution

the gradual change in a species over time

exocytosis

process by which vesicles release their contents outside the cell; active transport