Which of the following structures would carry out cellular respiration? A

Analyze the question: Cellular respiration happens only in living cells. So we need the option that is alive and metabolically active.

Concept: Cellular respiration is the breakdown of food (glucose) to release energy, usually with oxygen:

C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + energy

It needs living cells with working enzymes. Anything dead, denatured, or dormant with very low metabolism will not respire meaningfully.

Go through the options:

• A. Germinating seed: The seed is alive and growing. It respires very actively to get energy for growth. ✔
• B. Decolorised leaf: Decolorising usually means boiling the leaf in alcohol to remove chlorophyll (as in the starch test). This kills the cells, so no respiration. ✘
• C. Dry leaf: It is dead and lacks the water needed for metabolism. ✘
• D. Boiled cowpea: Boiling denatures the enzymes and kills the embryo, so no respiration. ✘

Answer: The germinating seed is the only living, metabolically active structure, so it is the one that carries out cellular respiration.

Tip: In experiments on respiration, germinating seeds are the "living" experiment, while boiled seeds are the "control". If you see boiled, dry, or decolorised (killed with hot alcohol), think "dead, so no respiration."