Crossing over shuffles alleles on:.a. sister chromatids. b. different non-homologous chromosomes. c. chromosomes within different cells. d. different homologous chromosomes. d. none of the answers are correct.

d

Explanation:

Crossing over shuffles alleles on non-sister chromatids of homologous chromosomes.

At the prophase I stage of meiosis, homologous chromosomes synapsed to form a four-chromatid structure known as tetrad. Exchange of chromosomal segments between non-sister chromatids of the tetrad then takes place, a process that results in the reshuffling of genes or alleles on the non-sister chromatids.

Hence, none of the answers is correct.

Correct option: d

•there must be variation for the particular trait within a population.

•the variation must be inheritable (that is, it must be capable of being passed on from the parents to their offspring).

•individuals with one version of the trait must produce more offspring than those with a different version of the trait.good

explanation: