Busy. Please wait.
or

show password
Forgot Password?

Don't have an account?  Sign up 
or

Username is available taken
show password

why


Make sure to remember your password. If you forget it there is no way for StudyStack to send you a reset link. You would need to create a new account.
We do not share your email address with others. It is only used to allow you to reset your password. For details read our Privacy Policy and Terms of Service.


Already a StudyStack user? Log In

Reset Password
Enter the associated with your account, and we'll email you a link to reset your password.

Remove ads
Don't know
Know
remaining cards
Save
0:01
To flip the current card, click it or press the Spacebar key.  To move the current card to one of the three colored boxes, click on the box.  You may also press the UP ARROW key to move the card to the "Know" box, the DOWN ARROW key to move the card to the "Don't know" box, or the RIGHT ARROW key to move the card to the Remaining box.  You may also click on the card displayed in any of the three boxes to bring that card back to the center.

Pass complete!

"Know" box contains:
Time elapsed:
Retries:
restart all cards




share
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.

  Normal Size     Small Size show me how

Gullett-Biology-Unit

Biology Unit 2 - Natural Selection

TermDefinition
biomass the total dry mass of all the organisms in a given area
energy pyramid a triangular diagram that shows an ecosystem's loss of energy, as energy passes through an ecosystem's food chain: each row in the pyramid represents a trophic level in an ecosystem and the area of row represents the total energy stored in that level
habitat the place where the organism usually lives
ecological niche all of the physical, chemical and biological factors that a species needs to survive, stay healthy, and reproduce in an ecosystem
competitive exclusion the exclusion of one species by another due to competition
ecological equivalent organisms that share a similar niche but live in different geographical regions
competition ecological relationship in which two organisms attempt to obtain the same resource
predation an interaction between two organisms in which one organism, the predator, kills and feeds on the other organism, the prey
symbiosis a relationship in which two different organisms live in close association with each other
mutualism a relationship between two species in which both species benefit
commensalism a relationship between two species in which one organism benefits and the other is unaffected
parasitism a relationship between two species in which one species, the parasite, benefits from the other species, the host, which is harmed
artificial selection the human practice of breeding animals or plants that have certain desired traits
heritability ability of a trait to be passed from one generation to the next
natural selection the process by which individuals that are better adapted to their environment survive and reproduce more successfully than less well adapted individuals do; a theory to explain the mechanism of evolution
population a group of organisms of the same species that live in a specific geographical area
fitness a measure of an organism's ability to survive and reproduce offspring relative to members of a population
gene pool the total set of genes, including all the alleles, that are present in a population at any one point in time
allele frequency proportion of one allele, compared with all the alleles for that trait, in the gene pool
normal distribution a distribution of numerical data whose graph forms a bell-shaped curve that is symmetrical about the mean
directional selection a natural selection process in which one genetic variation is selected and that causes a change in the overall genetic composition of a population
stabilizing selection a type of natural selection in which the average form of a trait is favored and becomes more common
disruptive selection a type of natural selection in which two extreme forms of a trait are selected
Created by: lpgullett