Make annotated drawings of transverse sections of leaves from xerophytic plants to explain how they are adapted to reduce water loss by transpiration

Sourav PanOctober 29, 2024

Answered

Here’s a description of how to create annotated drawings of transverse sections of leaves from xerophytic plants, along with explanations of their adaptations to reduce water loss by transpiration:

1. Cuticle

• Drawing: A thick, waxy layer on the upper surface of the leaf.
• Annotation: “Thick cuticle – Reduces water loss by acting as a barrier to evaporation.”

2. Upper Epidermis

• Drawing: A single layer of tightly packed cells.
• Annotation: “Upper epidermis – Protects the inner tissues and helps reduce water loss.”

3. Mesophyll

• Drawing: Two types of mesophyll cells:
  • Palisade Mesophyll: Columnar cells located beneath the upper epidermis.
  • Spongy Mesophyll: Loosely arranged cells with air spaces.
• Annotation: “Palisade mesophyll – Maximizes light absorption for photosynthesis. Spongy mesophyll – Provides gas exchange while minimizing water loss due to air spaces.”

4. Lower Epidermis

• Drawing: A single layer of cells containing stomata.
• Annotation: “Lower epidermis – Contains stomata that can close to reduce water loss.”

5. Guard Cells

• Drawing: Bean-shaped cells surrounding the stomata.
• Annotation: “Guard cells – Regulate the opening and closing of stomata to control water loss.”

6. Stomata

• Drawing: Openings in the lower epidermis.
• Annotation: “Stomata – Allow for gas exchange but can close to minimize water loss during dry conditions.”

7. Vascular Bundle

• Drawing: Xylem and phloem vessels.
• Annotation: “Vascular bundles – Xylem transports water and minerals; phloem transports sugars. Arrangement helps maintain structural integrity while minimizing water loss.”

Summary of Adaptations

• Thick Cuticle: Prevents excessive evaporation.
• Sunken Stomata: Often found in xerophytes, these reduce air movement and water loss.
• Leaf Shape: Many xerophytes have reduced leaf surface areas (e.g., needles or spines) to limit transpiration.
• C4 or CAM Photosynthesis: Some xerophytes utilize alternative pathways for photosynthesis that minimize water loss.