No, sperm is not always XY.
Sperm cells, also known as spermatozoa, are haploid cells, meaning they carry only one set of chromosomes. These chromosomes determine the sex of the offspring.
According to the provided reference, normal human spermatozoa carry either an X chromosome or a Y chromosome. This means there are two distinct types of sperm:
- X-bearing sperm: These sperm carry the X chromosome, which, when combined with an egg's X chromosome, result in a female offspring (XX).
- Y-bearing sperm: These sperm carry the Y chromosome, which, when combined with an egg's X chromosome, result in a male offspring (XY).
Here's a table summarizing the chromosome types found in human sperm:
| Sperm Type | Chromosome | Offspring Sex (When combined with Egg - X Chromosome) |
|---|---|---|
| X-Bearing Sperm | X | Female (XX) |
| Y-Bearing Sperm | Y | Male (XY) |
The reference also indicates that differences between X and Y spermatozoa may arise from:
- Different chromosomes: The X and Y chromosomes carry different genes, influencing various traits.
- Different structures and functions: Variations in genetic expression may lead to differences in how X and Y sperm operate.
Therefore, the correct answer is that sperm can be either X or Y, not always XY.
