Which of the given event does not happen during seed germination?

Options

A. Emergency of radicle
B. Increase in rate of respiration
C. Hydrolysis of stored polysaccharides and proteins
D. Photosynthesis by cotyledons

Answer

**Step-by-Step Solution:**

1. **Understanding Seed Germination**: Seed germination is the process by which a seed develops into a new plant. It involves several physiological changes that lead to the emergence of the seedling from the seed.

2. **Identifying Key Events in Seed Germination**:
- **Emergence of Radical**: This is the first visible sign of germination where the radical (embryonic root) emerges from the seed. This event definitely occurs during germination.
- **Increase in Rate of Respiration**: Seeds require energy for growth, which comes from cellular respiration. Therefore, the rate of respiration increases during germination.
- **Hydrolysis of Stored Polysaccharides and Proteins**: During germination, stored nutrients in the seed are broken down to provide energy and building blocks for the growing plant. This process is crucial for seed germination.
- **Photosynthesis by Cotyledon**: Cotyledons are the first leaves that appear during germination, but they do not perform photosynthesis immediately. Instead, they primarily serve as a food reserve for the developing seedling until true leaves develop.

3. **Analyzing the Options**:
- **Option 1 (Emergence of Radical)**: This happens during germination.
- **Option 2 (Increase in Rate of Respiration)**: This also occurs during germination.
- **Option 3 (Hydrolysis of Stored Polysaccharides and Proteins)**: This is a key event in germination.
- **Option 4 (Photosynthesis by Cotyledon)**: This does not happen during the initial stages of seed germination, as cotyledons do not photosynthesize until they are exposed to light and mature.

4. **Conclusion**: The event that does not happen during seed germination is **photosynthesis by cotyledon**.

**Final Answer**: The event that does not happen during seed germination is **photosynthesis by cotyledon**.

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