Question

Which of the following is an example of gametic incompatibility?

1) A male cat's reproductive organ does not fit in a female's reproductive tract
2) A male shark deposits his sperm in a female shark, but those sperm fail to attach to her eggs
3) A male abalone produces faster-swimming sperm than another male abalone
4) A male coral releases sperm at a different time of day than another male coral

Answer 1

Gametic incompatibility is showcased when a male shark's sperm cannot attach to a female shark's eggs, illustrating a failure in fertilization despite the gametes being close, thereby acting as a prezygotic barrier.

Step-by-step explanation:

Gametic incompatibility occurs when gametes (egg and sperm) from two different species are unable to fuse and create a zygote. This is a type of prezygotic barrier that prevents fertilization and subsequent offspring between potentially interbreeding species. The option that describes an example of gametic incompatibility is: (2) A male shark deposits his sperm in a female shark, but those sperm fail to attach to her eggs.

In this example, the sperm and egg are near each other, but the physiological or biochemical differences prevent the sperm from attaching to and fertilizing the egg. In contrast, the other options describe mechanical incompatibility, differences in mating behaviors, or sperm competition, which are distinct from gametic incompatibility. Gametic incompatibility is an important mechanism of reproductive isolation that preserves species boundaries by preventing the creation of hybrid organisms that may not survive or reproduce effectively.