Question

Which sieve elements do Angiosperms have?

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

Answer 1

Angiosperms have phloem tissue composed of sieve-tube elements and companion cells, where sieve-tube elements transport sugars and companion cells provide metabolic support.

Step-by-step explanation:

The sieve elements that Angiosperms have are sieve-tube elements and companion cells. In the phloem tissue, a series of sieve-tube cells are arranged end to end to form a long sieve tube, which is responsible for transporting organic substances such as sugars and amino acids. The sugars move from one sieve-tube cell to the next through sieve plates with perforations found at the cell junctions. While sieve-tube cells have reduced cell components and are missing a nucleus at maturity, companion cells are closely associated with them, containing more ribosomes and mitochondria and providing essential metabolic support and energy. These companion cells are connected to the sieve-tube elements through lateral sieve areas.