Question

Write the main functions of the stem.

Answer 1

Hint: Stem is a vascular part of the plant. It is mainly made up of epidermis, cortex, bast fibers, phloem and xylem. The stems may even have several nodes, and the distance between two nodes is commonly called internode.

Complete answer:
In a plant, stem is considered as a part of the shoot system. This supportive organ can be found above as in the majority of the cases, whereas it can also be present below the ground. The stem can perform a variety of crucial roles.
The primary function of a stem is to provide support and stature to the plant by grasping leaves, buds, flowers and fruits.
Another important function performed by stem is to connect roots of a plant to the leaves, where plants make their food in presence of chlorophyll and sunlight.
Stems are also meant for the transportation of essential nutrients such as water and minerals that are absorbed by roots from the soil. The nutrients are further passed to leaves and other tissues of the plant for their utilization in different processes. Xylem and phloem are the vascular tissues present in a plant. Thus, xylem carries water and minerals from roots to plant parts such as leaves, buds, and other developing plant organs via stem. However, phloem carries food products required by various plant tissues, parts or organs for their normal metabolic activities or ultimately the survival. Hence, this tissue is specialized for transportation of energy sources from the plant reserves such as leaves to various parts including roots. Stem consists of meristems (consisting of meristematic tissues), which help in regenerating the new living tissues.
In some cases, stems act as food storage parts of plants also, storing plant food in the form of starch. For example – In the case of potatoes, the stem modifies its structure to store excess food manufactured during photosynthesis.

Note:
The length and width of the stem varies greatly depending upon the plant species. A stem can be short as few millimeters, and long up to several feet. Stems can be of three types, namely aerial stem, sub-aerial stem, and underground stem. They can be even woody or herbaceous, thick or tender and single or highly branched as well.