One pair.....

The number of sex chromosomes in the zygote of humans is one pair. It is not always a perfect pair. In females, it is perfect with two X-chromosomes. However in males, there is one X-chromosome and one Y-chromosome

Number of pairs of sex chromosomes in the zygote of a human being:

The number of pairs of sex chromosomes in the zygote of a human being is one.

Explanation:

The zygote is formed when the sperm cell fertilizes the egg cell during sexual reproduction. The zygote contains a combination of chromosomes from both the mother and the father.

Sex Chromosomes:

Sex chromosomes are a type of chromosome that determines the sex of an individual. In humans, there are two types of sex chromosomes: X and Y.

- Females have two X chromosomes (XX), while males have one X and one Y chromosome (XY).

Determination of Sex in Humans:

The sex of a human is determined by the presence or absence of the Y chromosome. If the zygote receives an X chromosome from both the sperm and the egg, the individual will develop as a female (XX). If the zygote receives an X chromosome from the egg and a Y chromosome from the sperm, the individual will develop as a male (XY).

Autosomal Chromosomes:

Apart from the sex chromosomes, humans have 22 pairs of autosomal chromosomes. These chromosomes are responsible for determining other characteristics and traits of an individual, such as hair color, eye color, height, etc.

Visually appealing breakdown:

- The number of pairs of sex chromosomes in the zygote of a human being is one.
- Sex chromosomes determine the sex of an individual.
- Females have two X chromosomes (XX), while males have one X and one Y chromosome (XY).
- The presence or absence of the Y chromosome determines the sex of a human.
- Apart from sex chromosomes, humans have 22 pairs of autosomal chromosomes.