Assertion: Photorespiration is a wasteful process.
Reason: In photorespiratory pathway, there is not synthesis of sugars or ATP.

Explanation

### Step-by-Step Solution:

1. **Understanding the Assertion**: The assertion states that "Photorespiration is a wasteful process." To evaluate this, we need to understand what photorespiration entails and why it is considered wasteful.

2. **Defining Photorespiration**: Photorespiration is a metabolic pathway that occurs in plants, where the enzyme RuBisCO catalyzes the reaction of ribulose bisphosphate (RuBP) with oxygen instead of carbon dioxide. This process leads to the production of 2-phosphoglycolate, which is eventually converted back to RuBP, but not before releasing carbon dioxide.

3. **Analyzing the Reason**: The reason provided states that "In the photorespiratory pathway, there is no synthesis of sugars or ATP." This is a critical point because if photorespiration does not lead to the production of essential energy molecules (ATP) or sugars, it implies that the process does not contribute positively to the plant's energy needs.

4. **Connecting Assertion and Reason**: Since photorespiration consumes ATP and NADPH (which are produced during the light-dependent reactions of photosynthesis) without producing sugars or additional ATP, it is indeed a wasteful process. The plant expends energy without gaining any beneficial products.

5. **Conclusion**: Both the assertion and the reason are correct. The assertion is supported by the reason, which explains why photorespiration is considered wasteful.

### Final Answer:
Both the assertion and the reason are correct, and the reason is the correct explanation of the assertion.