The number of pair(s) of sex chromosomes in the zygote of humans is

Options

A. One
B. Tow
C. Three
D. Four

Explanation

To solve the question regarding the number of pairs of sex chromosomes in the zygote of humans, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Chromosome Structure in Humans**:
- Humans have a total of 23 pairs of chromosomes in each somatic cell. This includes both autosomes and sex chromosomes.

2. **Identify the Types of Chromosomes**:
- Out of the 23 pairs, 22 pairs are autosomes. These are chromosomes that do not determine the sex of an individual.
- The 23rd pair consists of sex chromosomes, which are responsible for determining the sex of the individual.

3. **Determine the Composition of Sex Chromosomes**:
- In females, the sex chromosomes are represented as XX.
- In males, the sex chromosomes are represented as XY.

4. **Count the Pairs of Sex Chromosomes**:
- Since there is only one pair of sex chromosomes (the 23rd pair), regardless of whether the individual is male or female, we conclude that there is only one pair of sex chromosomes.

5. **Conclusion**:
- Therefore, the number of pairs of sex chromosomes in the zygote of humans is 1.

### Final Answer:
The number of pair(s) of sex chromosomes in the zygote of humans is **1**.

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