To solve the question regarding the cell organelles L, M, N, and O using the provided dichotomous key, we can follow these steps:
### Step-by-Step Solution:
1. **Identify the Type of Membrane**:
- The first part of the dichotomous key asks whether the cell organelle is bounded by a double membrane or a single membrane.
- Since we need to categorize L, M, N, and O, we will analyze each one based on their membrane structure.
2. **Analyze Cell Organelle L**:
- According to the key, if it is a double membrane-bound organelle, we go to II.
- The options under II state:
- (a) Directs cell growth and controls its activities - L
- (b) Provides colour to flowers and fruits - M
- Since L directs cell growth and controls activities, this describes the **Nucleus**.
3. **Analyze Cell Organelle M**:
- The second part of II indicates that M provides color to flowers and fruits.
- This function is characteristic of **Plastids**, specifically **Chromoplasts**, which are responsible for color in flowers and fruits.
4. **Analyze Cell Organelle N**:
- Next, we look at the single membrane-bound organelles under III:
- (a) Removes dead cells and digests foreign material - N
- (b) Carries out some oxidative reactions in a cell - O
- The organelle that removes dead cells and digests foreign material is the **Lysosome**.
5. **Analyze Cell Organelle O**:
- For O, which carries out oxidative reactions, this is typically associated with **Peroxisomes**.
### Summary of Findings:
- L = Nucleus (double membrane)
- M = Chromoplast (double membrane)
- N = Lysosome (single membrane)
- O = Peroxisome (single membrane)
### Conclusion:
Based on the analysis, the correct identification of the cell organelles using the dichotomous key leads us to the conclusion that:
- L is the Nucleus,
- M is the Chromoplast,
- N is the Lysosome,
- O is the Peroxisome.
The correct option regarding cell organelles L - O is **Option 3**.
