Final answer:
A postzygotic barrier that impairs the hybrid's development or survival in its environment is called hybrid inviability, and another type is hybrid sterility. Hybrid inviability occurs when the genes of different parent species interact in ways that result in the hybrid being non-viable and unable to survive. Hybrid sterility, on the other hand, refers to the situation where the hybrid may develop and survive, but it is unable to produce offspring of its own.
Step-by-step explanation:
A postzygotic barrier that impairs the hybrid's development or survival in its environment is called hybrid inviability. This occurs when the genes of different parent species interact in ways that result in the hybrid being non-viable and unable to survive.
For example, the combination of genes from different species may lead to developmental abnormalities or physiological dysfunction that hinder the hybrid's ability to thrive in its environment. These impairments can prevent the hybrid from reaching adulthood and reproducing, ultimately leading to a lack of gene flow between the parent species.
Another type of postzygotic barrier is hybrid sterility. In this case, the hybrid may develop and survive, but it is unable to produce offspring of its own. This can occur due to differences in chromosome number or structural rearrangements, which result in reproductive organs and processes that are incompatible with successful reproduction.