Scale leaves are present in Potato

Scale leaves are a type of specialized leaves found in plants. They are modified leaves that have evolved to perform specific functions other than photosynthesis. Scale leaves are typically small, thin, and often translucent or colorless. They are usually found on the stems or rhizomes of plants and serve various purposes such as protection, storage, and reproduction.

Scale leaves in Potato
Potato plants (Solanum tuberosum) are known for their underground tubers, which are actually modified stems. However, above the ground, potato plants also have scale leaves. These scale leaves are found on the underground stems known as stolons. Stolons are horizontal stems that grow along the surface of the soil and produce tubers.

The scale leaves on potato stolons are small, thin, and brownish in color. They are closely packed together and protect the developing tubers from light, preventing them from turning green due to exposure to sunlight. These scale leaves also help in reducing water loss and providing insulation to the tubers.

Other options
a) Cactus: Cacti have modified leaves called spines, not scale leaves. Spines help cacti to reduce water loss and protect them from herbivores.

b) Tomato: Tomato plants have compound leaves with multiple leaflets. They do not have scale leaves.

c) Cucumber: Cucumber plants have simple leaves with rough and hairy surfaces. They do not have scale leaves.

Therefore, the correct answer is option D) Potato. Scale leaves are present on the stolons of the potato plant.