Question

Two dogs, a Great Dan and a Chihuahua, can't mate due to the incompatibility in size. What type of reproductive barrier limits breeding between these two types of dogs?

A temporal isolation
B. mechanical isolation
C hybrid viability
D. behavioral isolation
E. gametic isolation

Answer 1

The reproductive barrier that limits breeding between a Great Dane and a Chihuahua is mechanical isolation, which is a prezygotic barrier that occurs due to physical incompatibilities, preventing successful mating or fertilization. The correct answer is option b.

Step-by-step explanation:

The mating issue between a Great Dane and a Chihuahua is an example of a mechanical isolation reproductive barrier. Mechanical isolation occurs when two species are unable to mate due to physical incompatibilities, such as size differences that prevent successful mating or fertilization. This type of barrier is part of the prezygotic barriers, which impede mating or hinder fertilization if mating does occur. In contrast, other prezygotic barriers like temporal isolation are due to differences in breeding times, and gametic isolation occurs when gametes (egg and sperm) are incompatible. Hybrid viability and behavioral isolation are also possible reproductive isolations, but these do not apply to the scenario provided. The correct option for the type of reproductive barrier that limits breeding between a Great Dane and a Chihuahua due to incompatibility in size is B. mechanical isolation.