Ch 15 Biology

Question 1

Adaptive radiation

Answer 1

Diversification of a species into a number of different species that develops over time in response to an environmental factor, enabling the species to survive.

Question 2

Allopatric Speciation

Answer 2

Occurs when a population divided by a geographic barrier evolves into two or more populations unable to interbreed.

Question 3

Analogous Structure

Answer 3

Structure that has the same function but different construction and was not inherited from a common ancestor.

Question 4

Ancestral trait

Answer 4

More-primitive characteristic that appeared in common ancestors.

Question 5

Artificial Selection

Answer 5

Darwin’s term for the selective breeding of organisms selected for certain traits in order to produce offspring having those traits.

Question 6

Biogeography

Answer 6

Study of the distribution of plants and animals on Earth.

Question 7

Bottleneck

Answer 7

Process in which a large population declines in number, then rebounds.

Question 8

Derived Trait

Answer 8

New feature that had not appeared in common ancestors.

Question 9

Disruptive Selection

Answer 9

Process in which individuals with average traits are removed, creating two populations with extreme traits.

Question 10

Evolution

Answer 10

Hereditary changes in groups of living organisms over time.

Question 11

Fitness

Answer 11

Measure of a trait’s relative contribution to the following generation.

Question 12

Genetic Drift

Answer 12

Random change in allelic frequencies in a populations.

Question 13

Gradualism

Answer 13

Theory that evolution occurs in small, gradual steps over time.

Question 14

Homologous Structure

Answer 14

Anatomically similar structure inherited from a common ancestor.

Question 15

Mimicry

Answer 15

Morphological adaptation in which one species evolves to resemble another species for protection or other advantages.

Question 16

Natural Selection

Answer 16

Theory of evolution developed by Darwin, based on four ideas: excess reproduction, variations, inheritance, and the advantages of specific traits in an environment.

Question 17

Post-zygotic isolation mechanism

Answer 17

Occurring after formation of a zygote.

Question 18

Pre-zygotic isolation mechanism

Answer 18

Occurring before breeding; produces a fertilizing egg, or zygote.

Question 19

Punctuated Equilibrium

Answer 19

Theory that evolution occurs with relatively sudden periods of speciation followed by long periods of stability.

Question 20

Sexual Selection

Answer 20

Change in the frequency of a trait based on competition for a mate.

Question 21

Stabilizing Selection

Answer 21

Most common form of natural selection in which organisms with extreme expressions of a trait are removed.

Question 22

Sympatric Speciation

Answer 22

Occurs when a species evolves into a new species in an area within a geographic area.

Question 23

Vestigial Structure

Answer 23

reduced form of a functional structure that indicates shared ancestry.