(A) P, Q

(B) P, R

(C) Q, S

(D) P, S

Correct Answer

✅ Option (C): Q and S

Detailed Explanation

This question tests plant anatomy and physiology concepts related to cell specialization, phloem transport, guttation, and leaf movements.

Statement P

“Specialized parenchymatous cells with tannins and crystals of calcium oxalate are termed as sclereids.”
❌ Incorrect

• Such specialized parenchyma cells are called idioblasts.

• Sclereids are thick-walled lignified sclerenchyma cells, not parenchyma.

✘ Statement P is false.

Statement Q

“The sieve elements of angiosperms are surrounded by companion cells and are essential component of phloem loading.”
✅ Correct

• In angiosperms, sieve tube elements are closely associated with companion cells.

• Companion cells play a key role in phloem loading and unloading of sugars.

✔ Statement Q is true.

Statement R

“The exudation of water by guttation occurs through trichomes.”
❌ Incorrect

• Guttation occurs through hydathodes, not trichomes.

• Hydathodes are specialized structures located at leaf margins.

✘ Statement R is false.

Statement S

“The bulliform cells control the unrolling and hygroscopic movement of grass leaves.”
✅ Correct

• Bulliform (motor) cells are large, thin-walled epidermal cells in grasses.

• They regulate leaf rolling and unrolling in response to water availability.

✔ Statement S is true.

Why Option (C) Is Correct

• Q is correct (role of companion cells in phloem loading)

• S is correct (function of bulliform cells)

• Other options include at least one incorrect statement

✔ Therefore, the correct answer is Option (C): Q and S.

Quick Exam Memory Tips

• Idioblasts → Tannins & calcium oxalate crystals

• Phloem loading → Companion cells

• Guttation → Hydathodes (not trichomes)

• Bulliform cells → Leaf rolling in grasses

Exam Relevance

🔹 Frequently asked in CSIR-NET Life Sciences
🔹 Important for plant anatomy & physiology
🔹 High-yield true/false statement-based MCQs