Question

Which of the following plants DOES NOT has Krantz anatomy in their leaves?

• A. Sugarcane
• B. Maize
• C. Sorghum
• D. Wheat

Hint:

TEMPERATE crops like wheat, rice, barley, and oats are \( C_3 \) plants (no Krantz anatomy). TROPICAL/SUBTROPICAL crops like maize, sugarcane, and sorghum are \( C_4 \) plants (with Krantz anatomy).

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Plants are classified into \( C_3 \), \( C_4 \), and CAM groups based on their primary carbon dioxide fixation pathways.
Krantz anatomy (from the German word "Kranz", meaning wreath) is a specialized leaf structure characteristic of \( C_4 \) plants.
It features a concentric arrangement of bundle sheath cells surrounding the vascular bundle, which are in turn encircled by mesophyll cells.
Detailed Explanation:
In \( C_4 \) plants, this spatial separation between mesophyll and bundle sheath cells minimizes photorespiration.
Primary carbon fixation occurs in the mesophyll cells via PEP carboxylase, forming a 4-carbon acid that is transported to the bundle sheath cells, where Rubisco is localized.
Let us examine the plants in the options:
- Sugarcane, Maize, and Sorghum: These are classic \( C_4 \) plants adapted to hot, bright environments. They possess Krantz anatomy, allowing them to maintain high photosynthetic efficiency under high temperatures.
- Wheat: This is a temperate cereal crop that follows the \( C_3 \) photosynthetic pathway. It lacks the specialized bundle sheath structure of Krantz anatomy, and both primary carbon fixation and the Calvin cycle occur together within the mesophyll cells.
Therefore, wheat does not possess Krantz anatomy.

Step 2: Final Answer:
Wheat does not have Krantz anatomy in its leaves.