Final answer:
Autosomes are the same for both sexes and encompass 22 out of the 23 pairs of human chromosomes. Autosomes carry genes for non-sex-related characteristics, whereas sex chromosomes (X and Y) determine the sex of the individual.
Step-by-step explanation:
The correct answer to the student's question is A. Autosomes are chromosomes that are the same for both sexes. In humans, there are 23 pairs of chromosomes, and 22 pairs of these are autosomes. Autosomes contain genes for characteristics unrelated to sex determination, making them identical in both males and females.
Option B is incorrect because the Y chromosome is a sex chromosome, not an autosome. Similarly, option C is incorrect within the context of the question, although the X chromosome is present in both sexes, it is specifically classified as a sex chromosome, not an autosome. Option D is also incorrect as it mistakenly identifies autosomes as sex chromosomes, which is not the case.
The sex chromosomes in humans are the X and Y chromosomes, with females having two X chromosomes (XX) and males having one X and one Y chromosome (XY). The remaining 22 pairs of chromosomes are the autosomes which are the same in both sexes and do not determine sex. The autosomes are numbered 1 to 22 and carry the bulk of genetic material responsible for the various traits and functions within the human body.