Stage of Meiosis When Crossing Over Takes Place
Crossing over takes place in which stage of meiosis?
- Pachytene stage of Prophase-I — Correct Answer
- Diplotene stage of Prophase-I
- Metaphase of Meiosis I
- Metaphase of Meiosis II
Explanation:
Correct Answer: Pachytene stage of Prophase-I
Crossing over (exchange of segments between non-sister chromatids of homologous chromosomes) takes place during the pachytene stage of Prophase-I of Meiosis.
Stages of Prophase-I (Mnemonic: LZPDD)
| Stage | Key Events |
|---|---|
| Leptotene | Chromosomes begin to condense |
| Zygotene | Synapsis — homologous chromosomes pair (bivalent formation) |
| Pachytene | Crossing over — exchange between non-sister chromatids at chiasmata |
| Diplotene | Chiasmata visible; homologues begin to separate (but remain at chiasmata) |
| Diakinesis | Further condensation; chiasmata move to ends (terminalization) |
Crossing over is the 2nd biggest cause of genetic variation (after segregation).
📚 About this Topic — Animal Genetics & Breeding
This multiple choice question is from Animal Genetics & Breeding, Animal Refresher. It has 4 options with a detailed explanation of the correct answer. Practice more MCQs from Animal Genetics & Breeding to strengthen your preparation.
