Unit 4- Evolution & Classification

Question 1

directional selection

Answer 1

a change in the allele frequency of a population when an organism favors an extreme phenotype

Question 2

disruptive selection

Answer 2

a change in the allele frequency of a population when an organism is not favored for the most common phenotype

Question 3

stabilizing selection

Answer 3

favors the average individuals in a population

Question 4

geographical isolation

Answer 4

occurs when a physical barrier separates a population; ex. two populations are separated by a body of water or a mountain

Question 5

behavioral isolation

Answer 5

two populations have different courtship rituals;

Question 6

temporal isolation

Answer 6

occurs when two or more species reproduce at different times

Question 7

habitat isolation

Answer 7

two species live in the same area but live in different habitats within that area; ex. a species snake lives on land and another species of snake lives in water

Question 8

gametic isolation

Answer 8

sperm and egg cannot fuse because the surface proteins have changed

Question 9

mechanical isolation

Answer 9

sex organs of closely related species are incompatible (meaning they do not fit together)

Question 10

founder effect

Answer 10

allele frequencies change due to a migration; when a few individuals colonize a new habitat, the small founding population makes up the new gene pool; type of genetic drift

Question 11

evolution

Answer 11

a long slow process of change over time; a change in the gene pool over time

Question 12

bottleneck effect

Answer 12

drastic reduction in population size and by chance some individuals survive to make up the new gene pool; ex. natural disaster, fire, flood; type of genetic drift

Question 13

genetic drift

Answer 13

an accidental change in gene frequency that affects small populations only as a result of chance

Question 14

genetic equilibrium

Answer 14

a state of constant allele frequency in a population throughout generations

Question 15

vestigial structure

Answer 15

an anatomical organ in organisms that is no longer used or has a function; ex. appendix in humans, eyes in sightless species

Question 16

homologous structure

Answer 16

an anatomical structure that is found in different species, it has similar structure/make-up but different functions; ex arms, wings, and flippers

Question 17

analogous structure

Answer 17

a structure that is found in different species that has a dissimilar structure but similar function; ex a bird wing, bat wing & butterfly wing

Question 18

gene pool

Answer 18

the combined genetic material of all the members of a given population

Question 19

paleontologist

Answer 19

a scientist that studies fossils

Question 20

speciation

Answer 20

evolution of 1 or more new species from a single ancestor

Question 21

natural selection

Answer 21

Darwin’s idea that individuals best adapted to the environment will survive and reproduce; nature provides variation and nature chooses which traits are best adapted

Question 22

artificial selection

Answer 22

AKA selective breeding; nature provides variation and humans choose whcih traits are best adapted

Question 23

niche

Answer 23

the role of an organism in the environment

Question 24

adaptation

Answer 24

the long neck of a giraffe makes it better suited to survive

Question 25

fossil

Answer 25

preserved remains of ancient organisms

Question 26

Hardy-Weinburg

Answer 26

under specific conditions, allele frequencies will remain constant (equilibrium)

Question 27

Darwin

Answer 27

came up with the theory of natural selection; wrote book: On the Origin of Species by Means of Natural Selection

Question 28

Hutton

Answer 28

scientist that concluded the age of the earth was very old

Question 29

Malthus

Answer 29

theorized that the population of humans was growing too rapidly that supply couldn’t keep up with demand

Question 30

Lamarck

Answer 30

first to say that organisms change over time

Question 31

Lyell

Answer 31

explained how geological features change over time; wrote book: Principles of Geology

Question 32

Bonnet

Answer 32

coined the term “evolution”

Question 33

Wallace

Answer 33

collected plant and animal species and came up with a theory similar to Darwin’s

Question 34

relative frequency

Answer 34

the number of times an allele shows up in a gene pool