Biology Chapter 24: Barriers to Reproduction

Questions and Answers

Which of the following are examples of prezygotic barriers? (Select all that apply)

Mechanical isolation (correct)

Reduced hybrid viability

Temporal isolation (correct)

Hybrid breakdown

What is temporal isolation?

A prezygotic barrier where species breed during different times of the day, seasons, or years.

What is habitat isolation?

A prezygotic barrier where two species occupy different habitats within the same area.

What is behavioral isolation?

A prezygotic barrier where courtship rituals that attract mates act as reproductive barriers. Signup and view all the answers

What is mechanical isolation?

A prezygotic barrier where mating is attempted, but morphological differences prevent successful completion. Signup and view all the answers

What is gametic isolation?

A prezygotic barrier where sperm of one species may not fertilize the eggs of another species. Signup and view all the answers

Which of the following are examples of postzygotic barriers? (Select all that apply)

Reduced hybrid fertility Signup and view all the answers

What is reduced hybrid viability?

A postzygotic barrier where the genes of different parent species impair the hybrid's development or survival. Signup and view all the answers

What is reduced hybrid fertility?

A postzygotic barrier where hybrids are sterile. Signup and view all the answers

What is hybrid breakdown?

A postzygotic barrier where the first hybrid is viable, but subsequent generations are not fertile. Signup and view all the answers

Study Notes

Prezygotic Barriers

Prezygotic barriers prevent mating or fertilization between species.
Types of prezygotic barriers:
- Temporal isolation: Species breed at different times (day, season, year); example: skunks.
- Habitat isolation: Species live in different habitats within the same area; example: aquatic vs. terrestrial fruit flies.
- Behavioral isolation: Mating rituals affect attraction; example: blue-footed boobies' courtship behaviors.
- Mechanical isolation: Morphological differences hinder mating; example: incompatible snail shell shapes.
- Gametic isolation: Sperm of one species cannot fertilize eggs of another; example: sea urchins.

Postzygotic Barriers

Postzygotic barriers occur after fertilization, affecting hybrid offspring.
Types of postzygotic barriers:
- Reduced hybrid viability: Hybrids may have impaired development or survival due to gene interactions; example: salamander hybrids.
- Reduced hybrid fertility: Hybrids are sterile and cannot reproduce; example: mules (horse and donkey hybrids).
- Hybrid breakdown: First generation hybrids are viable, but subsequent generations fail to produce fertile offspring; example: some rice hybrids.

Description

Explore the concepts of prezygotic and postzygotic barriers in reproductive biology. This quiz covers various types of prezygotic barriers such as temporal, habitat, and behavioral isolation. Test your understanding of these critical evolutionary concepts!