The ultimate source of energy for photosynthetic reactions in a plant isMultiple Choiceglycogen.the sun.plants.glucose.catabolism.

Analyzing the Question

To determine the ultimate source of energy for photosynthetic reactions in a plant, we need to evaluate the provided options.

1. Glycogen: This is a storage form of glucose in animals, not directly involved in photosynthesis.
2. The Sun: The sun provides solar energy, which is crucial for photosynthesis, allowing plants to convert light energy into chemical energy.
3. Plants: While plants are the organisms performing photosynthesis, they are not the source of the energy.
4. Glucose: While glucose is produced during photosynthesis, it is not the source of energy for the process itself.
5. Catabolism: This refers to the metabolic process of breaking down molecules to obtain energy, but this process is not what powers photosynthesis.

Final Answer

The ultimate source of energy for photosynthetic reactions in a plant is the sun.