Question

Which of the following statements regarding photorespiration are correct? (A) Does not occur in C\(_3\) plants (B) CO\(_2\) is consumed and O\(_2\) is generated (C) Phosphoglycolate is formed (D) No synthesis of ATP and NADPH Choose the correct answer from the options given below :

• (a) and (b) only
• (a) and (d) only
• (c) and (d) only
• (b) and (d) only

Hint:

Photorespiration is often called a wasteful pathway because:

• O\(_2\) is consumed.

• CO\(_2\) is released.

• ATP is not synthesized.

• NADPH is not synthesized.

• Fixed carbon is lost.
It is most prominent in C\(_3\) plants.

Answer 1

The Correct Option is C

Step 1: Set up the situation.
Photorespiration starts when the enzyme RuBisCO grabs oxygen instead of carbon dioxide. We must judge each statement and keep only the correct ones.
Step 2: Check statement (a).
It says photorespiration does not occur in C$_3$ plants. In reality photorespiration is a typical feature of C$_3$ plants, while C$_4$ plants avoid it. So (a) is incorrect.
Step 3: Check statement (b).
It claims CO$_2$ is consumed and O$_2$ is generated. The truth is the opposite - O$_2$ is consumed and CO$_2$ is released. So (b) is incorrect.
Step 4: Check statement (c).
When RuBisCO works as an oxygenase, RuBP plus O$_2$ gives 3-PGA and 2-phosphoglycolate. So phosphoglycolate is formed and (c) is correct.
Step 5: Check statement (d).
Photorespiration is a wasteful path - no ATP and no NADPH are made, and fixed carbon is even lost as CO$_2$. So (d) is correct.
Step 6: Combine and conclude.
Only (c) and (d) are correct, which matches option 3.
\[ \boxed{(c)\ \text{and}\ (d)\ \text{only}} \]