AI-generated practice question — model-generated for extra practice, not a previous-year CBSE board question.
Plants store carbohydrates that are not used immediately in the form of starch, which serves as an internal energy reserve.
Source: Life Processes, Section 5.2.1 Autotrophic Nutrition
The answer is directly stated in the passage. The key term examiners look for is starch. You may also add "internal energy reserve" to complete the point. No extra elaboration is needed for 1 mark.