Find the odd one (w.r.t double carboxylation)
(a) Zea mays
(b) Euphorbia maculala
(c) Pisum sativum
(d) Amaranthus

Options

A. Zea mays
B. Euphorbia maculala
C. Pisum sativum
D. Amaranthus

Answer

To find the odd one out with respect to double carboxylation, we need to analyze the given options based on their classification as C3 or C4 plants.

### Step-by-Step Solution:

1. **Understand Double Carboxylation**:
- Double carboxylation is a process that occurs in C4 plants where carbon dioxide is fixed twice in different types of cells (mesophyll and bundle sheath cells).

2. **Identify the Plants**:
- (a) **Zea mays** - Commonly known as corn, it is a C4 plant.
- (b) **Euphorbia maculata** - Also a C4 plant.
- (c) **Pisum sativum** - Known as pea, it is a C3 plant.
- (d) **Amaranthus** - This is also a C4 plant.

3. **Classify the Plants**:
- C4 Plants: Zea mays, Euphorbia maculata, Amaranthus.
- C3 Plant: Pisum sativum.

4. **Determine the Odd One Out**:
- Since double carboxylation occurs in C4 plants and Pisum sativum is a C3 plant that only undergoes single carboxylation, it does not participate in double carboxylation.

5. **Conclusion**:
- The odd one out with respect to double carboxylation is **(c) Pisum sativum**.