Question

the figure shown indicates
sperm from neither echinometra viridis nor echinometra vanbrunti is able to fertilize an egg from echinometra lucunter.
click to view larger image.
options:

• gamete incompatibility.
• zygote death.
• allopatric speciation has occurred.
• ecological isolation.

Explanation:

The problem is about the inability of sperm from two species (Echinometra viridis and Echinometra vanbrunti) to fertilize the egg of Echinometra lucunter. Gamete incompatibility refers to the situation where gametes (sperm and egg) from different species cannot fuse to form a zygote. Zygote death would occur after fertilization, but here fertilization doesn't happen. Allopatric speciation involves geographic separation, which isn't indicated here. Ecological isolation is about different habitats, not gamete - level interactions. So the correct option is gamete incompatibility.

Answer:

A. gamete incompatibility.