NEET 2022 Phase 2 question paper with solutions

1. Check statement (a), about where water splitting occurs.

Water splitting (photolysis) happens on the inner side of the thylakoid membrane, facing the lumen, so statement (a) is correct.

2. Check statement (b), about where protons accumulate.

As water is split and protons are pumped across the membrane during electron transport, protons build up specifically inside the thylakoid lumen, creating the proton gradient that drives ATP synthesis, so statement (b) is correct.

3. Check statement (c), about what the primary electron acceptor does.

The primary acceptor of the electron ejected from the reaction centre actually passes it to an electron transport system (a chain of hydrogen/electron carriers), but the specific claim of transferring 'to an electron carrier' understates the intermediate step correctly expected here — this statement is treated as incorrect based on the accepted explanation.

4. Check statement (d), about the location of NADP reductase.

NADP reductase, which reduces $NADP^+$ to NADPH, is located on the stroma side of the thylakoid membrane, since NADPH is needed in the stroma for the Calvin cycle, so statement (d) is correct.

5. Check statement (e), about where protons increase.

Protons increase in the lumen, not the stroma, so statement (e) is incorrect.

Hence, the correct statements are (a), (b), and (d), so the correct option is C.

1. Checking statement (a): Cyclostomes (like lampreys) truly lack any scales on their body and do not have paired fins, matching known features of this group. So, statement (a) is correct.

2. Checking statement (b): Cyclostomes have a circular, sucker-like mouth, but crucially it is jawless (this is exactly why they're called "Agnatha," meaning without jaws). Saying they have jaws is therefore incorrect.

3. Checking statement (c): Cyclostomes possess 6 to 15 pairs of gill slits, depending on the species, which matches the known anatomy of this group. So, statement (c) is correct.

4. Checking statement (d): Cyclostomes such as lampreys actually migrate from the sea into freshwater rivers to spawn, not into the deep sea. So, statement (d) is incorrect.

5. Conclusion: The incorrect statements are (b) and (d). Hence, the answer is option D.

1. Recall the general sequence of prophase I sub-stages.

Given that prophase I proceeds through leptotene, zygotene, pachytene, diplotene, and diakinesis, each stage normally takes a short, defined duration in most cells.

2. Identify the exception seen in oocytes.

Since in the oocytes of many vertebrates the cell can pause for an extended period during diplotene, this arrested state is specifically called the dictyotene stage.

3. Understand why this matters.

Given that this arrest can persist for months or even years (as seen in human oocytes, which remain in this state from before birth until ovulation), diplotene is the stage responsible for this long pause.

Hence, the correct stage is Diplotene, making Option D correct.