Question

Which of the following is the main function of companion cells?

• A. Provide support through turgidity
• B. Controls the activities of sieve tube element
• C. Controls the movement of solutes in the sieve element
• D. Exchange of gases (CO${}_2$ and O${}_2$)

Answer 1

Answer: (B), (C)

The correct options are
B Controls the activities of sieve tube element
C Controls the movement of solutes in the sieve element

Companion cells, fibres, and parenchyma are the main parts of the phloem. It is a vascular tissue necessary for the transport of sugars, proteins, and mRNAs from the source to sink in plants.

The sieve-tube elements lack the nucleus at the maturity, so they are connected by companion cells to derive the nutrient as support.

Thus, the correct options B and C.