Question

question 3 of 10
when can alleles from linked genes be inherited independently?
a. when crossing over causes alleles to switch between homologous chromosomes
b. when alleles select two different chromosomes to be inherited on
c. when alleles travel up and down a chromosome to switch places
d. when alleles on the x chromosome move to the y chromosome

Explanation:

Linked genes are typically inherited together. However, during meiosis, crossing - over (a process in which homologous chromosomes exchange genetic material) can occur. When crossing - over happens between linked genes on homologous chromosomes, alleles can be recombined. This recombination allows alleles from linked genes to be inherited independently.

• Option B is incorrect because alleles do not "select" chromosomes. Chromosome segregation during meiosis is a random process based on the mechanics of cell division, not an active "selection" by alleles.
• Option C is incorrect. Alleles do not "travel up and down" a chromosome to switch places in the way described. Crossing - over between homologous chromosomes (not within a single chromosome in the manner suggested) is the relevant process.
• Option D is incorrect. While there can be some gene transfer between the X and Y chromosomes (in organisms with XY sex - determination), this is a more specialized case related to sex - chromosome evolution and not the general mechanism for independent inheritance of linked genes. The main and more general mechanism for independent inheritance of linked genes is crossing - over between homologous chromosomes.

Answer:

A. When crossing over causes alleles to switch between homologous chromosomes