The correct answer is c) starch. Autotrophs, like plants, store excess glucose produced during photosynthesis as starch.
Explanation:
Autotrophs:
Organisms that can produce their own food through photosynthesis or chemosynthesis.
Starch:
A polysaccharide (complex carbohydrate) that serves as the primary energy storage molecule in plants.
Glycogen:
A polysaccharide similar to starch, but it is the primary energy storage molecule in animals and fungi.
Proteins:
While proteins can be broken down for energy in extreme situations, they are primarily used for structural and functional roles in cells.
Fatty acids:
Found in lipids (fats and oils), they are also used for long-term energy storage in animals and some plants, but not the primary energy reserve in autotrophs.
In summary: In autotrophs, the internal cellular energy reserve is starch, which is synthesized from glucose produced during photosynthesis and stored for later use.