Biology- Prezygotic Isolating Mechanisms

Question 1

Behavioural Isolation

Answer 1

Different species use different courtships and other mating clues to find and attract a mate.
Example: Male frogs of different species have unique mating calls that attract ONLY females of their species

Question 2

Temporal Isolation

Answer 2

Different species breed at different times of the year
Example: Pussy willows produce flowers in the early spring- they are reproductively isolated from plant species that produce flowers at a different time of the year

Question 3

Ecological Isolation

Answer 3

Very similar species may occupy different habitats within a region
Example: Mountain bluebirds live at high elevations, eastern bluebirds prefer lower elevation- they will not encounter

Question 4

Mechanical Isolation

Answer 4

Differences in morphological features may make 2 species incompatible
Example: Male dam-species transfer sperm during an unusual mating fight. The male and female genitalia of each species are uniquely shaped and are physically incompatible with other species

Question 5

Gametic Isolation

Answer 5

Male gametes may not be able to recognize and fertilize an egg of a different species
Example: Marine animals release their sperm/eggs into the open water. Sperm Recognizes the eggs of their own species through chemical markers on the surface of the eggs