- A Apoplast is sometimes mistakenly thought to move water mainly through cell membranes; symplast mainly through cell walls
- B Apoplast = through cell walls and intercellular spaces (no membranes crossed); symplast = through connected cytoplasm via plasmodesmata
- C Apoplast and symplast are sometimes mistakenly thought to describe the exact same single continuous transport pathway in plant roots
- D Apoplast is sometimes mistakenly thought to transport mainly dissolved mineral ions; symplast mainly free water molecules
Correct answer: B. Apoplast = through cell walls and intercellular spaces (no membranes crossed); symplast = through connected cytoplasm via plasmodesmata
Explanation: Apoplast: water moves through cell walls and intercellular spaces without crossing membranes. Symplast: water moves through the cytoplasm connected by plasmodesmata. The Casparian strip forces water from apoplast to symplast at endodermis, controlling mineral entry.
Concept context
Internal tissue organisation: meristems, permanent tissues (xylem, phloem, parenchyma), and secondary growth. Frequently tested in NEET.