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

Companion cells are specialized parenchyma cells found in the phloem of flowering plants. They are living and nucleated, and they play a crucial role in the maintenance and function of sieve tube elements, aiding in the transport of substances.

The last produced secondary xylem remains located near the cambium ring. This is because the cambium ring is the region where new xylem and phloem cells are continuously produced in a plant. As the plant grows, older xylem cells are pushed towards the interior, while newer secondary xylem cells stay close to the cambium ring.

In a monocotyledenous stem, the vascular bundles are not arranged in a circle but are usually scattered throughout the ground tissue. There is no clearly defined pith as there is in many dicotyledonous species. As in the dicots the xylem of the bundles is pre-orientated toward the middles of the stem. Maize is a monocot. So, the vascular bundles in maize stem are scattered in ground tissue. 

In roots, the xylem is typically exarch, which means the protoxylem is located at the periphery and the metaxylem is towards the center. This is a characteristic arrangement in roots, facilitating the efficient transport of water and nutrients from the soil.

To match the organs with their correct types of vascular bundles, we need to understand the structure of the vascular bundles in these plants:

• Maize stem has a conjoint and closed vascular bundle.
• Cucurbita stem has a bicollateral and open vascular bundle.
• Sunflower stem has a conjoint and open vascular bundle.
• Maize root has a radial vascular bundle.

Therefore, the correct match is (p-3) (q-1) (r-4) (s-2).