Question

Which sieve elements do Gymnosperms have?

a) Sieve tubes and companion cells
b) Sieve cells only
c) Companion cells only
d) Sieve plates and sieve areas

Answer 1

Gymnosperms have sieve cells only as their phloem tissue, which serves to transport nutrients, but they lack the specialized sieve-tube elements and companion cells found in angiosperms.

Step-by-step explanation:

The sieve elements that gymnosperms have are sieve cells only. Unlike the phloem tissue in angiosperms, which consists of sieve-tube elements and companion cells, gymnosperms lack these structures. Instead, they have sieve cells, which perform a similar function in conducting nutrients throughout the plant. The gymnosperms' phloem tissue does not have the specialized companion cells that are found in angiosperms to assist the sieve-tube elements in metabolic functions and provide them with energy. Neither sieve plates nor sieve areas as seen in angiosperms' sieve-tube cells occur in gymnosperms.