Unit 4 Vocab

Question 1

Evolution

Answer 1

Change in the gene pool of a population from generation to generation by such processes as mutation, natural selection, and genetic drift

Question 2

Natural selection

Answer 2

The process by which forms of life having traits that better enable them to adapt to specific environmental pressures, as predators, changes in climate, or competition for food or mates, will tend to survive and reproduce in greater numbers than others of their kind, thus ensuring these dominant traits or future generations

Question 3

Homologous structure

Answer 3

Similar structures/body parts that appear in different organisms.

Question 4

Vestigial structure

Answer 4

Remnants of structures that had important functions in ancestral forms but are no longer essential

Question 5

Speciation

Answer 5

The formation of new species as the result of factors that prohibited interbreeding groups from breeding

Question 6

Adaptation

Answer 6

The ability of a species to survive in a particular ecological niche, especially because of alterations of form or behavior brought about through natural selection

Question 7

Gene pool

Answer 7

The total genetic information in the gametes of all organisms in a population

Question 8

Genetic equilibrium

Answer 8

When the frequency of a gene or allele doesn’t change from generation to generation

Question 9

Genetic drift

Answer 9

The change in frequency of a gene or allele from generation to generation

Question 10

Directional selection

Answer 10

A mode of natural selection where an extreme phenotype is favored over another, causing the allele frequency to shift over time towards that phenotype

Question 11

Disruptive selection

Answer 11

Type of natural selection that selects against the average. Usually 2 extremes but no inbetweens

Question 12

Artificial selection

Answer 12

When nature provides variations but humans pick the ones that they find most useful

Question 13

Stabilizing selection

Answer 13

Type of natural selection where population mean stabilizes on a particular trait value

Question 14

Reproductive isolation

Answer 14

Collection of processes that prevent the members of two different species that cross or mate from producing offspring, or which ensure that any offspring that may be produced are sterile.

Question 15

Geographic isolation

Answer 15

A population of organisms that are separated from exchanging genetic material with organisms of the same species.

Question 16

Behavioral isolation

Answer 16

Evolutionary mechanism that enables organisms of the same species to identify each other as proper mates

Question 17

Temporal isolation

Answer 17

Mechanism that prevents species from mating because they breed at different times

Question 18

Founder effect

Answer 18

Loss of genetic variation when a new population is made by a small part of a large population

Question 19

Relative frequency

Answer 19

The ratio of the number of times an event occurs to the number of times it is tested

Question 20

Niche

Answer 20

They way an organism fits into an ecological community or ecosystem