Answer:
In humans, a zygote will develop into a female if the sperm that fertilizes the egg has an X sex chromosome.
Step-by-step explanation:
The sex chromosomes contributed by the man are sexual determinants, since his gametes —sperms— possess both the X and Y sex chromosomes. In contrast, the eggs only possess the X sex chromosomes.
If an egg is fertilized by a sperm carrying the X sex chromosome, the zygote will have one pair of X chromosomes that will determine the female sex in the product.