Question

Transport of food material in higher plants takes place through
A. Sieve elements
B. Companion cells
C. Transfusion cells
D. Tracheids

Answer 1

Hint: Plants make food by a process called photosynthesis in the leaves of plants. This food then needs to be transported to various parts such as roots, stems, branches, etc; so that the normal functions of the plants can be performed normally and efficiently. Let us now understand the roles of various elements given in the question to find the correct answer.

Complete answer:
Let us first know about the cells given in options-
Sieve elements- Food made during photosynthesis by the plant leaves are transported to other parts of the plants by a conducting tube called phloem. Sieve elements are the specialised kind of cells which are important for the phloem to function properly. They are the major conducting cells present in phloem which help in transport of molecules across long distance.
Companion cells- These cells are also found within the phloem and are closely associated with the sieve tube elements. They are believed to have a regulatory role in the adjacent sieve element activity. They are also believed to have function in loading and unloading sugar into the sieve elements.
Transfusion cells- These are the tissues which are found around the vascular bundles in gymnosperms’ leaves. They are believed to help in the transportation of materials between vascular bundles and mesophyll.
Tracheids- They are elongated cells present in the xylem of vascular plants. They have their function in the transport of mineral salts and water.

From the above discussion, the correct answer is (A)- Sieve elements.

Note:
It is noteworthy to remember that the sieve tubes are long, pointed and narrow tubes present in the phloem of angiosperms whereas, companion cells serve to regulate the activity of the sieve tubes to which they are attached.
The functional basis of sieve elements in the transport of necessary macromolecules and carbohydrates can be applied in agriculture for the purpose to observe the ways in which resources are distributed to various parts of plants.