Question

a homologous chromosome pair is best described as:
select one:
a. two chromosomes that carry the same genes in the same positions, but may carry different alleles
b. two chromosomes that are randomly paired during meiosis, and may each contain the same genes or different genes.
c. two chromosomes that have the same alleles of the same genes in the same order.
d. two chromosomes that have different alleles of the same genes arranged in a different order.

Explanation:

Homologous chromosomes are pairs (one from each parent) with the same gene loci (positions) but may have different alleles (gene variants). Option a matches this definition: same genes in same positions, possible different alleles. Option b is wrong (not random pairing), c is wrong (not same alleles), d is wrong (same gene order).

Answer:

a. Two chromosomes that carry the same genes in the same positions, but may carry different alleles