Plant Nutrition (Plant Physiology)

The maximum amount of water is absorbed by root hairs. These are outermost layer of zone of cell maturation. Root hairs are thin, elongated extensions of epidermal cells, which are the outermost layer of the root.

Their primary function is to increase the surface area available for water and mineral uptake from the soil. Water absorption by root hairs occurs through osmosis, where water moves from a region of high concentration (the soil) to a region of lower concentration (the root hair cell).

The numerous root hairs and their thin walls provide a large surface area for water and nutrient uptake, allowing plants to efficiently absorb water from the soil.

Root hairs are primarily found in the root hair zone, which is located behind the root tip and is the region of the root where water absorption is most efficient.

Guard cells regulate the size of the stomatal opening. Exchange of gases with atmosphere and transpiration take place through stomata and guard cells play an important role in the working of stomata. Hence, all three statements are correct.

The closing and opening of the stomata rely on the pressure that is caused by the water’s osmotic flow in the guard cells. The change in the guard cell's turgor pressure causes the stomata to open and close.

Due to increased transpiration pull during the day, water is absorbed by the roots and transferred through the xylem to various areas of the plant causing the guard cell to swell and become turgid.

The stomatal pore is open as a result. The guard cell shrinks and becomes stiff at night because the roots absorb less water. Consequently, stomatal pores close. So the correct option is (c).

Water reaches great heights in trees because of suction pull caused by transpiration. The loss of water vapour from the plant cools the plant down when the weather is very hot, and water from the stem and roots moves upward as it is 'pulled' into the leaves.

On the other hand, plants absorb water and minerals from the soil via their roots but water does not move upward due to absorption. Similarly, water escapes the tree through evaporation. Hence, option (c) is the correct answer.

When the bark of a tree cut in circular form near the base of its stem, flow of nutrients (photosynthetic food from green leaves) stops towards the roots because phloem which is the transporting tissue for food is absent. In this way roots of the plant gets no energy. so the plant gradually dries up or dies.

The movement of water and minerals through the xylem is primarily driven by transpiration, the evaporation of water from leaves.

This creates a negative pressure (or "suction") that pulls water upwards from the roots through the xylem vessels. This process is vital for the plant's ability to carry out photosynthesis, transport nutrients to all parts of the plant, and maintain overall plant health.