Prezygotic barrier

Definition

Prezygotic barriers are mechanisms that prevent fertilization from occurring between different species. They ensure reproductive isolation by hindering mating or the fusion of gametes before zygote formation.

5 Must Know Facts For Your Next Test

1. Prezygotic barriers include temporal isolation, where species breed at different times.
2. Behavioral isolation occurs when differences in mating rituals prevent interbreeding.
3. Mechanical isolation involves incompatibilities in reproductive structures of different species.
4. Geographical isolation prevents species from mating due to physical separation.
5. Gametic isolation happens when sperm and egg cells from different species are incompatible.

Review Questions

• What is a prezygotic barrier and how does it function?
• Name and describe two types of prezygotic barriers.
• How does behavioral isolation contribute to speciation?

Related terms

postzygotic barrier:

Reproductive isolating mechanism that occurs after fertilization, leading to hybrid inviability or sterility

speciation:

The evolutionary process through which new biological species arise

hybrid zone:

A geographic area where interbreeding occurs between two species, often leading to hybrids