Genetic diversity is the total number of genetic characteristics in a species. Explain how chromosomal crossover contributes to genetic diversity.
a) Chromosomal crossover is a specific, non-random process during which chromosomes are linked together and exchange DNA, contributing to the genetic diversity.
b) Chromosomal crossover occurs during meiosis when chromosome pairs are linked and exchange DNA. Thus, crossover increases the variance of genetic combinations in the haploid gamete cell.
c) Chromosomal crossover results in the inheritance of genetic material by offspring and the recombination event is not variable in frequency or location.
d) Chromosomal crossover occurs during the mitotic process when chromosomes are linked together and recombination takes place, increasing the variance of genetic combinations in the haploid mitotic cells formed from mitosis.

Genetic diversity may be defined as the number of total genetic characteristics of a species. Genetic diversity helps the population to adapt in the changing environment. Crossing over provides a source of genetic diversity.

Crossing over is the process of exchange of genetic material during the process of meiosis. Thus, crossing over increases the variation of genetic characteristic in the haploid gamete cells.

Thus, the correct answer is option (b).