Question

The Y chromosome:

a) Is larger than the X chromosome
b) Contains more genes than the X chromosome
c) Is the same size as the X chromosome
d) Is smaller than the X chromosome
e) Is genetically identical to the X chromosome

Answer 1

The Y chromosome is smaller than the X chromosome and has fewer genes, with the SRY gene being significant for male sex determination. Sex-linked genes are often found on the X chromosome, and females have a homologous pair of X chromosomes, unlike males with one X and one Y chromosome.

Step-by-step explanation:

The Y chromosome is indeed smaller than the X chromosome. While the X chromosome contains about 2,000 genes, the Y chromosome has fewer than 100 genes. This difference in gene count is significant, considering that even the smallest autosome (chromosome 22) has over 500 genes. Importantly, almost all of the genes on the X chromosome are not related to sex, whereas the Y chromosome houses the specific genes that determine sex. The most notable of these is the SRY gene, necessary for male development. On the other hand, the absence of a Y chromosome results in female development, the default sex for humans.

Regarding the size of genetic materials, from smallest to largest it is: base pair, gene, chromosome. Sex-linked genes are predominantly located on the X chromosome because it carries many more genes than the Y chromosome. Males have one X and one Y chromosome (XY), which are not homologous, while females have two X chromosomes (XX), which are homologous.