Gene for maleness is present in humans over

Options

A. X-chromosome
B. Y-chromosome
C. Autosome
D. All the above.

Answer

**Step-by-Step Solution:**

1. **Understanding Chromosomes**: Humans have a total of 23 pairs of chromosomes, which include 22 pairs of autosomes and 1 pair of sex chromosomes. The sex chromosomes determine an individual's sex.

2. **Identifying Sex Chromosomes**: The sex chromosomes in humans are X and Y. Males have one X and one Y chromosome (XY), while females have two X chromosomes (XX).

3. **Locating the Gene for Maleness**: The gene responsible for maleness is located on the Y chromosome. This chromosome contains specific genes that trigger male development.

4. **Analyzing the Y Chromosome**: The Y chromosome is relatively small compared to the X chromosome, containing about 58 million base pairs and over 200 genes. Among these, there are genes that are specifically involved in male sex determination and spermatogenesis.

5. **Conclusion**: Since the gene for maleness is found on the Y chromosome, the correct answer to the question is the Y chromosome.

**Final Answer**: The gene for maleness is present in humans on the Y chromosome.

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