The incorrect statement about autotrophs is (c) They convert carbon dioxide and water into carbohydrates in the absence of sunlight.
Explanation: Autotrophs, like plants, use sunlight and chlorophyll to synthesize carbohydrates through photosynthesis. They need sunlight to convert carbon dioxide and water into carbohydrates.
Why other options are correct:
(a) They synthesize carbohydrates from carbon dioxide and water in the presence of sunlight and chlorophyll: This is the definition of photosynthesis, the process by which autotrophs create their own food.
(b) They store carbohydrates in the form of starch: Autotrophs store the carbohydrates they produce, often as starch, for later use as energy.
(d) They constitute the first trophic level in food chains: Autotrophs are the primary producers in a food chain, meaning they are the first level of organisms that create their own food, forming the base of the ecosystem.