in isobilateral leaves

Options

A. lower surface is brighter green
B. upper surface is lighter green
C. both the surface are equally green
D. upper surface is dark green while the lower surface is lighter green

Answer

### Step-by-Step Solution:

1. **Understanding Isobilateral Leaves**:
- Isobilateral leaves are characterized by having similar structures on both the upper and lower surfaces. This means that the mesophyll tissues are not differentiated into distinct layers like palisade and spongy parenchyma.

2. **Analyzing the Options**:
- The options provided are:
1. Lower surface is brighter green.
2. Upper surface is lighter green.
3. Both surfaces are equally green.
4. Upper surface is dark green but the lower surface is lighter green.

3. **Identifying Characteristics**:
- In isobilateral leaves, since the mesophyll is not differentiated, both surfaces have a similar appearance. This includes having an equal number of stomata and similar chlorophyll content, leading to equal coloration.

4. **Evaluating Each Option**:
- **Option 1**: Lower surface is brighter green - This is incorrect because both surfaces should have similar coloration.
- **Option 2**: Upper surface is lighter green - This is also incorrect for the same reason.
- **Option 3**: Both surfaces are equally green - This is correct as per the characteristics of isobilateral leaves.
- **Option 4**: Upper surface is dark green but the lower surface is lighter green - This is incorrect as it contradicts the definition of isobilateral leaves.

5. **Conclusion**:
- The correct answer is **Option 3: Both surfaces are equally green**. This is because isobilateral leaves have a uniform structure and coloration on both sides.