Which of the following statement regarding `C_(4)` plants is false

Options

A. The primary `CO_(2)` acceptor is a 5-carbon molecule
B. The initial carboxylation reaction occurs in mesophyll
C. Calvin pathway does not take place in the mesophyll cells but does so only in bundle sheath cells
D. Leaves that fix `CO_(2)` have two cell types

Answer

To determine which statement regarding C4 plants is false, we need to analyze the characteristics and processes associated with these plants. Here’s a step-by-step solution:

### Step 1: Understand C4 Plants
C4 plants are specialized plants that have adapted to arid and tropical environments. They utilize a unique photosynthetic pathway known as the C4 cycle, which allows them to efficiently fix carbon dioxide even under conditions of low carbon dioxide concentration and high temperatures.

**Hint:** C4 plants are adapted to specific environments and have a unique photosynthesis pathway.

### Step 2: Identify the Primary Carbon Dioxide Acceptor
In C4 plants, the primary carbon dioxide acceptor is not a 5-carbon molecule. Instead, it is a 3-carbon molecule called phosphoenolpyruvate (PEP). PEP combines with carbon dioxide to form a 4-carbon compound, oxaloacetic acid.

**Hint:** Remember the role of phosphoenolpyruvate (PEP) in the C4 cycle.

### Step 3: Analyze the Statements
1. **Statement about Primary Carbon Dioxide Acceptor**: If a statement claims that the primary carbon dioxide acceptor is a 5-carbon molecule, this is incorrect. The correct acceptor is PEP, a 3-carbon molecule.

2. **Location of Initial Carboxylation**: The initial carboxylation occurs in the mesophyll cells, where PEP carboxylase is present. This statement is true.

3. **Presence of Rubisco**: Rubisco is present in the bundle sheath cells, where the Calvin cycle occurs. This statement is also true.

4. **Cell Types in Leaves**: C4 plants have two types of cells: mesophyll cells and bundle sheath cells. This is a true statement.

**Hint:** Evaluate each statement based on the known facts about C4 plants.

### Step 4: Conclusion
The only false statement regarding C4 plants is the one that claims the primary carbon dioxide acceptor is a 5-carbon molecule. Therefore, this statement is the answer to the question.

**Final Answer:** The false statement regarding C4 plants is that the primary carbon dioxide acceptor is a 5-carbon molecule.