Botany MCQs for NEET — Practice Questions with Answers

Collenchyma is typically absent in roots. Collenchyma cells provide support and are usually found in the stems and leaves of dicot plants, but they are not commonly found in roots. Roots mainly contain parenchyma, sclerenchyma, and various types of meristematic tissues.

Collenchyma tissue is absent in monocots. Monocot plants generally have a simpler vascular structure and do not have the thickened, flexible cell walls of collenchyma which are essential for support in dicots.

Sclerenchyma is the simple permanent tissue formed of dead cells. These cells have thick lignified walls and function primarily to provide structural support to the plant.

The apical meristem is a region of actively dividing cells at the tips of roots and shoots in plants. These cells are responsible for primary growth, which increases the length of the plant. This allows the plant to grow taller and roots to extend further into the soil.

Phloem fibres, also known as bast fibres, are the dead elements in the phloem tissue. They provide structural support to the plant and do not participate in the transport of nutrients, unlike sieve cells and companion cells, which are living elements.

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.