The initial clue about the genetic/chromosomal mechanism of sex determination can be traced back to some of the experiments carried out in

Options

A. Human beings
B. Birds
C. Insects
D. Plants

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about the initial experiments that provided clues regarding the genetic or chromosomal mechanism of sex determination.

2. **Identifying the Organisms Used in Experiments**: The experiments that provided the first clues about sex determination were primarily conducted on insects.

3. **Key Experiment and Discoveries**: In 1891, a scientist named Henking observed a specific structure during spermatogenesis in certain insects. He noted that 50% of the sperm contained this structure, which he named the "X body."

4. **Naming the Chromosome**: Although Henking did not initially understand the significance of this structure, it was later identified as the X chromosome.

5. **Sex Determination Mechanism in Insects**: It was found that in many insects, the sex determination mechanism follows an XX-XY system, where females have two X chromosomes (XX) and males have one X chromosome (XY).

6. **Generalization to Other Organisms**: This initial research laid the groundwork for understanding sex determination in other organisms, including humans (XX-XY system) and birds (ZZ-ZW system).

7. **Conclusion**: The experiments conducted on insects were crucial in tracing the genetic and chromosomal mechanisms of sex determination, leading to broader insights across various species.

**Final Answer**: The initial clue about the genetic/chromosomal mechanism of sex determination can be traced back to experiments carried out in insects.

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