Question

The process of respiration in plants generally takes place in
A. Chloroplast
B. Mitochondria
C. Cytoplasm
D. Grana
1. (A) and (B) only
2. (A) and (D) only
3. (B) and (C) only
4. (A), (B) and (C) only

• A. 1
• B. 2
• C. 3
• D. 4

Hint:

To remember cell organelle functions:
- ______Chloroplast/Grana:______ Sugar ______Production______ (Photosynthesis).
- ______Cytoplasm/Mitochondria:______ Sugar ______Consumption______ (Respiration).

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Cellular respiration is the biochemical process where plant cells break down glucose to generate energy in the form of ATP.
This multi-step metabolic pathway is compartmentalized into specific organelles and cellular structures.

Step 2: Detailed Explanation:
The complete process of aerobic respiration in plants is divided into three major stages:
1. Glycolysis: This first stage involves the partial breakdown of glucose into pyruvate. It occurs entirely in the liquid matrix of the cell, known as the ______Cytoplasm______ (C). No oxygen is required for this step.
2. Krebs Cycle (TCA Cycle): This occurs in the ______Mitochondrial matrix______ (B). Pyruvate is converted to acetyl-CoA, which is oxidized to release $\text{CO}_2$ and generate reduced coenzymes ($\text{NADH}$ and $\text{FADH}_2$).
3. Electron Transport Chain (ETC) and Oxidative Phosphorylation: This occurs on the inner membrane (cristae) of the ______Mitochondria______ (B) to synthesize the bulk of the ATP.
Let us evaluate the other options:
- Chloroplasts (A) and Grana (D) are the sites of photosynthesis (light and dark reactions), not cellular respiration.
Therefore, respiration takes place in the Cytoplasm (Glycolysis) and Mitochondria (Krebs cycle and ETC).
This matches statement (B) and (C) only, which corresponds to option (C).

Step 3: Final Answer:
The correct option is (C), as respiration occurs in the mitochondria and cytoplasm.