Question

Which of the following statements about the autotrophs is incorrect?

• A. They synthesize carbohydrates from carbon dioxide and water in the presence of sunlight and chlorophyll
• B. They store carbohydrates in the form of starch
• C. They convert carbon dioxide and water into carbohydrates in the absence of sunlight
• D. They constitute the first trophic level in food chains

Answer 1

The correct option is C

They convert carbon dioxide and water into carbohydrates in the absence of sunlight

The correct option is C.

The explanation for the correct option:

1. Autotrophs are primary producers.
2. They are found at the first trophic level of an ecosystem.
3. Plants use carbon dioxide, water, and sunlight for photosynthesis.
4. The photosynthesis process takes place within the mesophyll cells found in the leaves.
5. The carbohydrate produced during this process is stored in the plant as starch.
6. It is used to generate energy.
7. In the presence of sunlight, the conversion of carbon dioxide and water into carbohydrates.

The explanation for the incorrect option:

Option A:

1. Autotrophs are green plants.
2. They can prepare their own food by photosynthesis.
3. For the purpose of photosynthesis, they need carbon dioxide, water, and sunlight.
4. These are the basic raw materials needed for the preparation of food in autotrophs.

Option B:

1. The autotrophs prepare food with the help of sunlight and chlorophyll pigment.
2. The by-product of photosynthesis is glucose and oxygen.
3. They release oxygen into the atmosphere.
4. Glucose is stored in form of starch in plants.

Option D:

1. Autotrophs are considered producers.
2. It is because they are able to produce their own food.
3. Other animals depend upon them for food.
4. Hence, they occupy the first trophic level of the food chain.

Final answer: They convert carbon dioxide and water into carbohydrates in the absence of sunlight is incorrect