Question

Dissolution of the synaptonemal complex occurs during:

• A. Pachytene
• B. Zygotene
• C. Diplotene
• D. Leptotene

Answer 1

The Correct Option is C

The synaptonemal complex (SC) is a protein structure that forms between homologous chromosomes during meiosis. Its main role is to mediate synapsis, the pairing of homologous chromosomes, and facilitate genetic recombination or crossing over.

To understand when the dissolution of the synaptonemal complex occurs, let's go through the stages of prophase I of meiosis:

1. Leptotene: During this stage, chromosomes start to condense, and homologous chromosomes begin to search for each other, but synapsis has not yet started. The synaptonemal complex has not formed yet.
2. Zygotene: Synapsis begins, and homologous chromosomes start to closely associate. The synaptonemal complex begins to form.
3. Pachytene: This is the stage where the synaptonemal complex is fully formed. Crossing over, or genetic recombination, happens at this stage.
4. Diplotene: This stage is marked by the beginning of the dissolution of the synaptonemal complex. The homologous chromosomes start to separate slightly, even though they remain attached at chiasmata, which are the sites where crossing over occurred.

Conclusion: The correct answer is that the dissolution of the synaptonemal complex occurs during the Diplotene stage. This is when the synaptonemal complex breaks down, and homologous chromosomes begin to pull apart, except at the chiasmata.