Unit 7: Chapter 24

Question 1

macroevolution

Answer 1

evolutionary change above the species level

Question 2

anagenesis

Answer 2

phyletic evolution

transforms one species into another

Question 3

cladogenesis

Answer 3

branching evolution

the splitting of a gene pool

gives rise to one or more new species while retaining the original species

Question 4

biological species

Answer 4

reproductively compatible

they cannot interbreed with other species

their offspring are fertile

Question 5

reproductive isolation

Answer 5

the existence of biological factors or barriers that impede two species from producing viable, fertile hybrids

Question 6

two types of biological factors

Answer 6

prezygotic and postzygotic

Question 7

five kinds of prezygotic barriers

Answer 7

habitat isolation

temporal isolation

behavioral isolation

mechanical isolation

genetic isolation

Question 8

habitat isolation

Answer 8

two species occupy different habitats

Question 9

temporal isolation

Answer 9

two species breed at different times of day or season

Question 10

behavioral isolation

Answer 10

certain courtship rituals of behaviors prevent species from mating with others

Question 11

mechanical isolation

Answer 11

physical differences prevent successful mating

Question 12

gametic isolation

Answer 12

the sperm of one species can’t fertilize eggs of another

Question 13

prezygotic barriers

Answer 13

impede mating or hinder fertilization if mating does occur

Question 14

postzygotic barriers

Answer 14

prevent the hybrid zygote from developing into a viable, fertile adult

Question 15

three types of postzygotic barriers

Answer 15

reduced hybrid viability

reduced hybrid fertility

hybrid breakdown

Question 16

reduced hybrid viability

Answer 16

genes of the different parent species interact and impair the hybrid’s development

Question 17

reduced hybrid fertility

Answer 17

hybrids can still be sterile even if they survive

Question 18

hybrid breakdown

Answer 18

some first generation hybrids are sterile but the second generation is not

Question 19

allopatric speciation

Answer 19

gene flow is interrupted when a population is divided into geographically isolated subpopulations

reproductive isolation must be established

Question 20

sympatric speciation

Answer 20

speciation takes place in geographically overlapping populations

happens through polyploidy and autopolyploidy and allopolyploidy

Question 21

polyploidy

Answer 21

the presence of extra sets of chromosomes due to accidents during cell division

Question 22

autopolyploidy

Answer 22

an individual has more than two chromosomes sets derived from the same species

Question 23

allopolyploidy

Answer 23

individual has multiple sets of chromosomes derived from different species

Question 24

adaptive radiation

Answer 24

the evolution of diversely adapted species from a common ancestor

occurs due to introduction to new environmental opportunities and challenges

Question 25

punctuated equilibrium

Answer 25

periods of continuity punctuated by sudden change

Question 26

heterochrony

Answer 26

evolutionary change in the rate or timing of developmental events

can have a significant impact on body shape

Question 27

allometric growth

Answer 27

the proportioning that helps give a body its specific form

Question 28

paedomorphosis

Answer 28

the rate of reproductive development accelerates compared to somatic development

a sexually mature species may retain body features that were juvenile structures in an ancestral species

Question 29

speciation

Answer 29

the origin of new species