In humans, what is the only homologous chromosome pair that isn't the same?
i also want to answer this because it's not on here anywhere. the answer is 23 in males. this is the sex chromosome and for males it's an xy.

Answer;

-23 in males

In humans, 23 in males is the only homologous chromosome pair that isn't the same.

Explanation;

-In humans, each cell normally contains 23 pairs of chromosomes, for a total of 46.

-Twenty-two of these pairs, called autosomes, look the same in both males and females. The 23rd pair, the sex chromosomes, differ between males and females. Females have two copies of the X chromosome, while males have one X and one Y chromosome.

-The 22 autosomes are numbered by size. The other two chromosomes, X and Y, are the sex chromosomes.

we would need to see the picture to answer it

multiple allele inheritance is traits controlled by more than 2 alleles (ex: pigeons having 3 alleles of one gene govern their feather color).   so the answer is a.