In human male progeny contains XY chromosome

female progeny contains XX chromosome

Ovum fertilization and development of zygote into female

When an ovum (egg) is fertilized by a sperm carrying an X-chromosome, the resulting zygote will develop into a female. This is because the female sex is determined by the presence of two X-chromosomes (XX).

Explanation:

During sexual reproduction, the father contributes a sperm cell carrying either an X or a Y chromosome, while the mother always contributes an X chromosome through her ovum. If the sperm carrying an X chromosome fertilizes the ovum, the resulting zygote will have two X chromosomes (XX), which leads to the development of a female individual.

Genetic basis:

The sex chromosomes, X and Y, determine the individual's sex. Females have two X chromosomes (XX), while males have one X and one Y chromosome (XY). The presence of the Y chromosome triggers the development of male characteristics.

Sex determination:

The sex of an individual is determined at the moment of fertilization when the sperm carrying either an X or Y chromosome fuses with the ovum. If the sperm carries an X chromosome, it will result in an XX zygote, leading to the development of a female. On the other hand, if the sperm carries a Y chromosome, it will result in an XY zygote, leading to the development of a male.

Exceptions:

While the majority of individuals follow this pattern of sex determination, there are some exceptions. For example, individuals with variations in sex chromosome composition such as XXY or XO may not fit neatly into the binary male-female classification. These conditions may lead to variations in sexual development and reproductive abilities.

In conclusion, when an ovum is fertilized by a sperm carrying an X-chromosome, the resulting zygote develops into a female. This is due to the presence of two X chromosomes (XX) in females, which is the genetic basis for their sexual development.