Which one of the following functions is carried out by green plants but not by animals?

Options

A. Excretion
B. Growth
C. Photosynthesis
D. Respiration

Answer

To determine which function is carried out by green plants but not by animals, we can analyze the options provided:

1. **Excretion**:
- Excretion is the process of removing waste products from the body. Both plants and animals perform excretion. In animals, nitrogenous wastes are excreted, while in plants, oxygen (a byproduct of photosynthesis) and excess water are expelled. Therefore, this option is incorrect.

2. **Growth**:
- Growth refers to the increase in size and mass of an organism, which occurs through cell division. Both plants and animals exhibit growth. Thus, this option is also incorrect.

3. **Photosynthesis**:
- Photosynthesis is the process by which green plants, using chlorophyll, convert light energy into chemical energy, producing their own food from carbon dioxide and water. Animals do not have chlorophyll and cannot perform photosynthesis; they rely on plants for their food. Therefore, this option is correct.

4. **Respiration**:
- Respiration is a process that occurs in both plants and animals, where oxygen is used to convert food into energy, releasing carbon dioxide as a byproduct. Thus, this option is incorrect.

Based on the analysis, the correct answer is **photosynthesis**, as it is a function carried out by green plants but not by animals.

### Summary of Steps:
1. Analyze each option provided in the question.
2. Determine if the function is performed by both plants and animals or just by plants.
3. Identify photosynthesis as the unique function of green plants.