Unit 7 Vocab

Question 1

population

Answer 1

group of organisms in a geographic area that can reproduce

Question 2

gene pool

Answer 2

all the alleles in a given population

Question 3

genetic drift

Answer 3

process wherein the gene pool of a population quickly shifts; more likely to occur in a small population

Question 4

bottleneck genetic drift

Answer 4

occurs when an environmental disaster wipes out a large portion of the gene pool

Question 5

founder genetic drift

Answer 5

occurs when a small segment of a population leaves, creating a small gene pool

Question 6

gene flow

Answer 6

the transfer of genes to a new population

Question 7

adaptive radiation

Answer 7

form of speciation wherein natural selection results in rapid diversification

Question 8

directional natural selection

Answer 8

occurs when there is a shift in the overall mean phenotype

Question 9

disruptive natural selection

Answer 9

occurs when there is a selection against the mean phenotype

Question 10

stabilizing natural selection

Answer 10

occurs when there is heavy natural selection for the mean phenotype

Question 11

sexual selection

Answer 11

process of selection for mates based on particular traits

Question 12

Miller-Urey experiment

Answer 12

Experiment that proved early Earth conditions could result in the creation of the basic organic molecules needed to build life

Question 13

reproductive isolation

Answer 13

a prezygotic barrier that makes it impossible for two different species to mate

Question 14

prezygotic barriers

Answer 14

barriers to reproduction that exist before the creation of a zygote

Question 15

postzygotic barriers

Answer 15

barriers that occur after the creation of a zygote and prevent the fertility of offspring

Question 16

habitat isolation

Answer 16

prezygotic barrier which occurs when two populations become genetically distinct due to different habitat preferences

Question 17

temporal isolation

Answer 17

prezygotic barrier that occurs when two populations have different mating seasons

Question 18

behavioral isolation

Answer 18

prezygotic barrier that prevents reproduction between two populations due to different courting and mating rituals

Question 19

mechanical isolation

Answer 19

prezygotic barrier that occurs when, quite frankly, the parts don’t fit

Question 20

gametic isolation

Answer 20

prezygotic barrier that prevents a gamete from forming (ex. sperm and egg don’t match up)

Question 21

reduced hybrid survivability

Answer 21

form of postzygotic barrier that prevents offspring from surviving to reproductive age

Question 22

reduced hybrid viability

Answer 22

form of postzygotic barrier that prevents a hybrid from reproducing

Question 23

hybrid breakdown

Answer 23

form of postzygotic barrier that results from the creation of weak offspring

Question 24

allopatric speciation

Answer 24

form of speciation that occurs due to geographic barriers

Question 25

artificial selection

Answer 25

process whereby humans select plants or animals for preferred traits

Question 26

sympatric speciation

Answer 26

form of speciation that occurs in the same geographic locale

Question 27

polyploidy

Answer 27

condition wherein an organism has more than two sets of chromosomes

Question 28

gradualism theory

Answer 28

theory that speciation occurs slowly

Question 29

punctuated equilibrium theory

Answer 29

theory that speciation occurs in quick bursts

Question 30

convergent evolution

Answer 30

process whereby two or more distinct species evolve similiar traits due to similar environmental pressures

Question 31

date of Earth's formation

Answer 31

4.6 billion years ago

Question 32

date of habitability of Earth

Answer 32

3.9 billion years ago

Question 33

date of first fossilized evidence for life

Answer 33

3.5 billion years ago

Question 34

RNA world hypothesis

Answer 34

hypothesis which states that RNA was the origin of life, whose proponents point to its ability to replicate, be an enzyme, form spontaneously, and its presence on meteorites