Problem 109 - Objective Biology for NEET

Question

Kranz type of anatomy is found in (a) \(\mathrm{C}_{2}\) plants (b) \(\mathrm{C}_{3}\) plants (c) \(\mathrm{C}_{4}\) plants (d) CAM plants

Step-by-Step Solution

Answer

Kranz type of anatomy is found in C4 plants

Step 1: Choice evaluation

Walk through each given choice and see if it aligns with the fact that Kranz anatomy is found predominantly in C4 plants.

Step 2: Choice A

Evaluate choice A: C2 plants. However, C2 plants do not possess Kranz anatomy, so this option is incorrect.

Step 3: Choice B

Evaluate choice B: C3 plants. These don't have the Kranz anatomy since it's a characteristic feature of C4 plants. Therefore, this choice is incorrect.

Step 4: Choice C

Evaluate choice C: C4 plants. These are known to have Kranz anatomy. So, this option is correct.

Step 5: Choice D

Evaluate choice D: CAM plants. These plants have a modified form of photosynthesis, but it does not involve Kranz anatomy. So, this option is incorrect.

Key Concepts

C4 Plants

C4 plants are a group of plants that have adapted their photosynthetic process to efficiently capture carbon dioxide under conditions such as high temperatures and intense sunlight. This adaptation is significant because it allows these plants to perform photosynthesis without losing water excessively. A key feature of C4 plants is the presence of Kranz anatomy, a special structure in their leaves that optimizes the photosynthetic process.

• Kranz anatomy involves the arrangement of cells in concentric circles. Specifically, the bundle-sheath cells encircle the veins, while the mesophyll cells form an outer ring.
• This setup helps in minimizing photorespiration, a wasteful process that occurs in other types of photosynthetic plants.
• Examples of C4 plants include corn, sugarcane, and certain types of grasses.

Due to these unique structural features, C4 plants are exceptionally efficient in environments where other plants struggle, particularly in arid regions.

Photosynthesis

Photosynthesis is the process by which green plants, algae, and some bacteria convert light energy into chemical energy, mainly in the form of glucose. It's a crucial process for life on Earth as it is the foundation of the food chain.

• Photosynthesis occurs mainly in the chloroplasts of plant cells where it uses sunlight, carbon dioxide, and water.
• The process releases oxygen as a byproduct, which is vital for most life forms on Earth.
• Photosynthesis can be split into two stages: the light-dependent reactions and the Calvin cycle.

The light-dependent reactions take place in the thylakoid membranes and generate ATP and NADPH, which are then used in the Calvin cycle.
In C4 and CAM plants, adaptations exist to increase efficiency in photosynthesis under specific environmental conditions.

Plant Anatomy

Plant anatomy focuses on the structure of plant parts such as roots, stems, and leaves, providing insight into how plants grow and function. One critical component of plant anatomy relating to photosynthesis is the vascular system, which includes xylem and phloem tissues.

• Xylem transports water and minerals absorbed from the roots to the rest of the plant, which is essential for photosynthesis.
• Phloem distributes the sugars and other metabolic products downward from the leaves.

Kranz anatomy is an important feature in C4 plant structures. This aspect of plant anatomy specifically involves the organization of leaf veins, where the special arrangement of bundle-sheath cells plays a crucial role in promoting efficient carbon fixation.
Overall, understanding plant anatomy helps in grasping how plants sustain themselves and adapt to varying environmental conditions.