Final answer:
Most sex-linked genes are on the X chromosome because it contains more genetic information than the Y chromosome, which has significantly fewer genes.
Step-by-step explanation:
Most sex-linked genes are located on the X chromosome because the X chromosome has significantly more genetic information than the Y chromosome. The X chromosome is indeed much larger than the Y chromosome and contains approximately 2,000 genes, compared to the Y chromosome which has fewer than 100 genes. Furthermore, the Y chromosome's genes are not essential to survival, while the X chromosome has many genes that are unrelated to sex, and it is inherited by both males (XY) and females (XX), effectively ensuring the genes are more widely disseminated in the population. Therefore, the most accurate reason why most sex-linked genes are on the X chromosome is: A. Because the X chromosome carries more genetic information than the Y chromosome.