▶️ Answer/Explanation
For a seed to germinate, it requires three specific environmental conditions: water, oxygen, and a suitable temperature. Water is essential to activate the enzymes that break down food reserves, while oxygen is required for aerobic respiration to provide the energy needed for growth. Carbon dioxide is not required because the seed is not yet performing photosynthesis; similarly, chlorophyll is only needed once the plant develops green leaves. Since the apparatus is designed to measure respiration by absorbing produced gases, the seeds must have the basic requirements to stay alive and grow.
✅ Answer: (D)
✅ Answer: (D)
▶️ Answer/Explanation
For seeds to germinate, they require three essential conditions: water, oxygen, and a suitable temperature. In setup (A), the temperature is too low ($0$ °C) for enzyme activity. In setup (C), the lack of moisture (dry cotton wool) prevents the seed from swelling and activating metabolism. In setup (D), the layer of oil and boiled water prevent oxygen from reaching the seeds, stopping aerobic respiration. Setup (B) provides all necessary conditions: moisture for hydration, $25$ °C for optimal enzyme function, and access to atmospheric oxygen.
✅ Answer: (B)
✅ Answer: (B)
▶️ Answer/Explanation
Detailed solution
The correct answer is D.
Seed germination requires three specific conditions: water, oxygen, and a suitable temperature. Water is essential to soften the seed coat and activate enzymes that break down stored food reserves. Oxygen is required for aerobic respiration to provide the energy (ATP) needed for growth and cell division. Unlike mature plants, germinating seeds do not need sunlight or carbon dioxide because they rely on internal food stores rather than photosynthesis, and they obtain mineral ions from those same reserves initially.