Unit 2 - Isolating Mechanisms

Question 1

Hybrid

Answer 1

offspring resulting from interspecific mating

Question 2

Reproductive Isolating
Mechanisms

Answer 2

barriers to gene flow between populations of different species are required to prevent hybrids from forming

Question 3

Pre-Zygotic

Answer 3

prevent fertilization from occurring

Question 4

Habitat Isolation

Answer 4

species members occupy different habitats or geographic areas

Question 5

Temporal Isolation

Answer 5

species members are active at different times of day or seasons

Question 6

Behavioral Isolation

Answer 6

differences in courtship rituals prevent members of different species from recognizing each other

Question 7

Mechanical Isolation

Answer 7

morphological differences between sexes of different species prevent mating (key and lock don’t fit)

Question 8

Gametic Isolation

Answer 8

fertilization is blocked; gametes
can’t get to or can’t recognize each other

Question 9

Post-Zygotic

Answer 9

preventative measures post-womb

Question 10

Hybrid breakdown

Answer 10

hybrids survive, are fertile but have very low fitness (their offspring may also be sterile, inviable)

Question 11

Reduced Hybrid Viability

Answer 11

hybrids don’t survive to reproduce, don’t complete development

Question 12

Reduced Hybrid Fertility

Answer 12

viable hybrids are sterile