Question

Kranz type of anatomy is found in
A. C3 plants
B. C2 plants
C. C4 plants
D. CAM plants

Answer 1

Hint: The plants are classified based on their morphological and physiological characteristics. Some of the plants have different tissue arrangements that get modified over the time to get advanced plants and Kranz anatomy is one of such modifications that developed in some types of plants.

Complete Answer:
- The word kranz means ring, the kranz anatomy specialized structure found in some plants in which the mesophyll cells are clustered around the bundle sheath cells and form a ring-like structure. The chloroplast number in the bundle sheath cells is more in comparison to the mesophyll cells, such type of anatomy is found in dicot plants like maize.
- Now, the Kranz anatomy is found in C4 plants, the light dependent reactions and the calvin cycle are not linked in C4 plants. The calvin cycle takes place in the bundle sheath cells and the light-dependent reactions take place in the mesophyll cells.
- In C4 plants, the oxygen fixation takes place first to form 4 carbon molecules called oxaloacetate in the mesophyll cells with the help of PEP carboxylase. This oxaloacetate is converted to malate and moved to the bundle sheath cells which get dissociated and carbon dioxide is released.
- The Rubisco molecule fixes the carbon dioxide and produces sugar. Inside the bundle sheath cells the carbon dioxide is pumped constantly through the mesophyll cells this results in the increase of carbon dioxide around Rubisco and reduces the photorespiration.

Thus, the correct option is ‘C’. C4 plants.

Note: In C3 and C2 plants the carbon dioxide is fixed to form three carbon molecules with the help of Ribulose bisphosphate carboxylase oxygenase that is rubisco. This enzyme also involves in the reaction with oxygen the results in photorespiration. So, to overcome this production of wasteful process C4 pathway fixes the carbon dioxide with the help of phosphophenol pyruvate carboxylase.