Plant Anatomy Plant Tissues MCQs for NEET — Botany Questions with Answers

Companion cells regulate the function of sieve tubes in phloem tissue. These cells are closely associated with sieve tube elements and help in the transport of nutrients by maintaining the pressure gradient necessary for the flow of phloem sap.

The central region of the stem and root is known as the medulla or pith. It is a core of parenchyma cells that store nutrients and provide structural support to the plant.

The apical meristem is responsible for the increase in the length of the plant. It is located at the tips of roots and shoots and contributes to primary growth, allowing the plant to extend in height.

In the phloem tissue, the dead elements are the phloem fibers. Unlike sieve cells, sieve tubes, and companion cells, which are living, phloem fibers are sclerenchymatous cells and provide mechanical strength to the tissue. Therefore, they are considered dead at maturity.

Companion cells are specialized parenchyma cells found in the phloem of flowering plants. They are closely associated with sieve tube elements and help regulate the function of sieve tubes. Companion cells assist in the loading and unloading of materials into the sieve tube elements, ensuring the efficient transport of nutrients.

Root hairs are unicellular extensions of root epidermal cells. They greatly increase the surface area of the root, allowing for more efficient absorption of water and nutrients from the soil. Unlike multicellular structures, root hairs are single cells that grow outwards from the root epidermis.

The central region of the stem and root is known as the medulla or pith. The pith is composed of parenchyma cells and is located at the core of the stem or root. It serves as a storage area for nutrients and helps in the transport of water and other substances.

Lenticels are associated with gaseous exchange in plants. They are small, spongy openings in the bark of stems and roots that allow oxygen to enter the plant and carbon dioxide to exit. This process is crucial for respiration and other metabolic activities.

Sieve tube elements are living cells that form part of the phloem tissue in plants, responsible for the transport of nutrients. However, mature sieve tube elements lack a nucleus. Instead, they rely on companion cells to perform necessary cellular functions.