Answer: A flattened, photosynthetic stem that resembles a leaf, found in Opuntia (cactus).
- A A modified adventitious root specially adapted for climbing surfaces and structures
- B A flattened, photosynthetic stem that resembles a leaf, found in Opuntia (cactus)
- C A swollen underground bulb specially adapted for storing food during dormancy
- D A spine-like modified leaf adapted mainly for defense against herbivores
Correct answer: B. A flattened, photosynthetic stem that resembles a leaf, found in Opuntia (cactus)
Explanation: A phylloclade is a flattened, green, photosynthetic stem that performs leaf functions. Found in Opuntia (cactus) and Casuarina. The true leaves are reduced to spines or scales to reduce water loss in dry habitats.
In a dicot stem, vascular bundles are arranged in a single ring (with cambium between xylem and phloem, enabling secondary growth); in a monocot stem, bundles are scattered throughout with no cambium, so monocots can't undergo secondary growth (no wood formation).
Concept context
External structure of roots, stems, and leaves plus internal tissue organization. High marks in Class 11 and NEET.