Biology- Postzygotic Isolating Mechanisms

Question 1

Zygotic Mortality

Answer 1

Mating and fertilization are possible, but genetic differences result in a zygote that is unable to develop properly
Example: Some sheep and goat species are able to mate but zygote in not viable

Question 2

Hybrid Inviability

Answer 2

A hybrid individual develops but either dies before birth, or if born alive, cannot survive to maturity
Examples: When tigers and leopards are crossed, zygote begins to develop but ends in miscarriage or stillborn

Question 3

Hybrid Infertility

Answer 3

Hybrid offspring remain healthy and viable but are sterile

Example: Mules are the sterile hybrid offspring of a horse-donkey cross