The diagram shows a section through the leaf of a flowering plant.
Where does photosynthesis take place?
A) 1 and 2
B) 1 and 4
C) 2 and 3
D) 3 and 4
▶️ Answer/Explanation
Ans: B) 1 and 4
Photosynthesis occurs primarily in chloroplast-rich cells. The Palisade Mesophyll (1) is densely packed with chloroplasts, making it the main site of photosynthesis. The Lower Epidermis (4) contains guard cells with chloroplasts, which also contribute to photosynthesis.
The Vascular Bundle (2) is involved in transport, not photosynthesis, while the Spongy Mesophyll (3) plays a minor role. Thus, the correct answer is B (1 and 4).
| Label | Structure | Function | Involved in Photosynthesis? |
|---|---|---|---|
| 1 | Palisade Mesophyll | Main site of photosynthesis, packed with chloroplasts | Yes (major role) |
| 2 | Vascular Bundle | Transports water & food (xylem/phloem) | No |
| 3 | Spongy Mesophyll | Some photosynthesis, mostly gas exchange | Yes (minor role) |
| 4 | Lower Epidermis | Has stomata + guard cells (with chloroplasts) | Yes (minor role) |
The diagram shows a cross-section of part of a leaf. Which structure is the cuticle?
▶️ Answer/Explanation
Ans: A
The cuticle is a waxy, waterproof layer covering the outer surface of the leaf (epidermis) to reduce water loss. In the diagram, it is the outermost layer labeled A. Other structures like stomata (B), palisade mesophyll (C), or vascular bundles (D) are internal and serve different functions. Thus, the correct answer is A (Cuticle).