Understanding Speciation and Reproductive Barriers

What is the starting point of macro-evolution?

• Genetic drift

• Hybridization

• Speciation

• Natural selection

Which type of isolation occurs when two species do not encounter each other due to a geographic barrier?

• Mechanical isolation

• Habitat isolation

• Behavioral isolation

• Temporal isolation

What is an example of mechanical isolation?

• Two species breeding at different times

• Two species not recognizing each other as mates

• A bee not fitting into a flower for pollination

• Sperm and egg not fusing

What happens in reduced hybrid viability?

• Hybrids are fertile but weak

• Hybrids are strong but infertile

• Hybrids thrive over generations

• Hybrids fail to develop normally

Which postzygotic barrier results in hybrids that are strong but cannot reproduce?

• Hybrid breakdown

• Genetic isolation

• Reduced hybrid viability

• Reduced hybrid fertility

What is hybrid breakdown?

• Hybrids fail to thrive over multiple generations

• Hybrids are strong and fertile

• Hybrids are infertile from the first generation

• Hybrids are viable but weak

What is allopatric speciation?

• Formation of species through polyploidy

• Formation of hybrids in a hybrid zone

• Formation of new species due to geographic barriers

• Formation of new species without geographic barriers

Which type of speciation occurs without a geographic barrier?

• Sympatric speciation

• Allopatric speciation

• Temporal speciation

• Hybrid speciation

What is the most common mechanism of sympatric speciation?

• Polyploidy

• Natural selection

• Genetic drift

• Hybridization

How does polyploidy contribute to speciation?

• By enhancing natural selection

• By increasing chromosome numbers

• By creating geographic barriers

• By increasing genetic drift