Synaptonemal complex was first described by

Options

A. Moses
B. Bowmann
C. Montgomery
D. Pfitzner.

Answer

**Step-by-Step Solution:**

1. **Understanding the Synaptonemal Complex**: The synaptonemal complex is a protein structure that forms between homologous chromosomes during the zygotene stage of prophase I in meiosis. It is crucial for the process of crossing over and genetic recombination.

2. **Identifying the Stage of Formation**: The synaptonemal complex appears during the zygotene stage of prophase I. This is when homologous chromosomes pair up and become closely associated.

3. **Function of the Synaptonemal Complex**: The primary function of the synaptonemal complex is to facilitate crossing over, which is the exchange of genetic material between homologous chromosomes, leading to genetic diversity.

4. **Dissolution of the Complex**: The synaptonemal complex dissolves during the diplotene stage of prophase I, which is important for the subsequent steps of meiosis.

5. **Historical Context**: The synaptonemal complex was first described by scientists in 1956. The two key figures are Mosses and Fawcett, who independently observed this structure in different organisms.

6. **Specific Observations**: Mosses observed the synaptonemal complex in the spermatocytes of crayfish, while Fawcett observed it in the spermatocytes of various animals, including pigeons, cats, and humans.

7. **Conclusion**: Based on the information provided, the correct answer to the question "Synaptonemal complex was first described by" is Mosses.

**Final Answer**: Mosses

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