Apoplastic phloem loading is inhibited by PCMBS because it blocks:
Answer: C) Membrane transporters. For PSS- Sec-F-Transport, remember the key idea and you’ll land on this option; the distractors usually swap cause and effect or confuse similar terms. Avoid: A) Photosynthesis; B) Plasmodesmata; D) Xylem flow. Name the process first, then pick the option that describes it — don’t reverse cause and effect.
Ref: Best CSIR NET Plant Physiology books: Master Unit 6 with Taiz & Zeiger and Salisbury & Ross. Crack Part C experimental questions with top textbooks.