Select correct option w.r.t chromosomes number in sexual life cycle of apple

Options

A. Megasporocyte - 34, Microspore 17, PEN -51
B. Oosphere - 34, Nucellus - 34, Pollengrain - 17
C. Meiospore - 34, Microspore -17, Embryo-34
D. Meiocyte - 34, Sporocyte - 34, Pollen tetrad -34

Answer

To solve the question regarding the chromosome number in the sexual life cycle of the apple plant, we will analyze each option step by step.

### Step-by-Step Solution:

1. **Understanding the Chromosome Numbers**:
- In the apple plant, the haploid chromosome number (n) is 17.
- The diploid chromosome number (2n) is 34.

2. **Analyzing Each Option**:
- **Option 1**:
- Megasporocyte: 34 (Diploid, correct)
- Microspore: 17 (Haploid, correct)
- Pen (Pollen grain): 51 (Triploid, correct since it is formed from the fusion of the polar nuclei and haploid pollen grain)
- Oospore: 34 (Diploid, correct)
- Nucellus: 34 (Diploid, correct)
- Pollen grain: 17 (Haploid, correct)
- **Conclusion**: All components are correct. **This option is correct.**

- **Option 2**:
- Oospore: 34 (Diploid, incorrect because the oospore is haploid)
- Nucellus: 34 (Diploid, correct)
- Pollen grain: 17 (Haploid, correct)
- **Conclusion**: Oospore is incorrect. **This option is incorrect.**

- **Option 3**:
- Meiospore: 34 (Incorrect, should be 17 as they are haploid)
- Microspore: 17 (Haploid, correct)
- Embryo: 34 (Diploid, correct)
- **Conclusion**: Meiospore is incorrect. **This option is incorrect.**

- **Option 4**:
- Meocyte: 34 (Diploid, correct)
- Sporocyte: 34 (Diploid, correct)
- Pollen tetrad: 34 (Incorrect, should be 17 as they are haploid)
- **Conclusion**: Pollen tetrad is incorrect. **This option is incorrect.**

3. **Final Answer**:
- The correct option regarding the chromosome number in the sexual life cycle of the apple plant is **Option 1**.