Question

Males are heterogametic because
A) They can produce two types of gametes.
B) They produce two similar gametes.
C) They are able to produce both eggs and sperms.
D) Both A and B

Answer 1

Hint: Male has a Y chromosome that helps in determining offspring’s sex. This is due to the SRY gene that presence in the region of Y chromosome that decides sex.

Complete Answer:
- Sex chromosome is one of a pair of chromosomes deciding whether an individual is female or male.
- Scientists mark the sex chromosomes of human beings and other animals as X and Y.
- The sex chromosomes in humans comprise of one pair of 23 pairs of chromosomes total.
The remaining 22 chromosome pairs are called autosomes.
- Individuals who have two X chromosomes (XX) are female; those who have one X chromosome and one Y chromosome (XY) are male.

Now, let us find the solution from the options-
- Heterogametic sex refers to a population where the sex chromosomes are not the identical.
- Males produce dissimilar gametes, such as two forms of spermatozoa, one with the X chromosome and the other with the Y chromosome, are generated.
- If the sperm holds X and fuses with the ovum, the result would be a girl foetus. If sperm carries Y fuses with ovum, then a male child will develop.

Thus, the correct answer is option (A) they can produce two types of gametes.

Note: In mammals, males with an X and a Y sex chromosome would be considered heterogametic sex, while females with two X sex chromosomes would be considered homogametic sex.