In the frog genus, when certain species attempt to mate with other species, embryo development is halted at various stages including zygotic segmentation, blastula formation, gastrulation, or in the final phases of embryo development. the stage at which the developing frog arrests depends on the species involved in the cross. this is an example of

a.

hybrid breakdown.

b.

hybrid sterility.

c.

hybrid inviability.

d.

sexual isolation.

Option D.

Sexual isolation.

Explanation:

Sexual isolation is a process in which a species of organism is unable to breed or mate from related species successfully due to environment, physiological, behavioral or genetic difference making its to depend on species involved in the cross. Examples is found in amphibians frogs and toads. Breakdown of sexual isolation lead to hybrid sterility, hybrid invaibility or poor gene flow.

a unit of heredity that is transferred from a parent to offspring and is held to determine some characteristic of the offspring.