Question

When sieve-tube members line up end to end, forming a long series, they produce structures called ______ _________ (2 blanks)

Answer 1

Phloem tissue is composed of sieve-tube cells arranged end to end to form a long sieve tube. These cells transport organic substances such as sugars and amino acids. Companion cells provide metabolic support to the sieve-tube cells.

Step-by-step explanation:

Phloem tissue is composed of sieve-tube cells, companion cells, phloem parenchyma, and phloem fibers. A series of sieve-tube cells (also called sieve-tube elements) are arranged end to end to make up a long sieve tube, which transports organic substances such as sugars and amino acids.

The sugars flow from one sieve-tube cell to the next through perforated sieve plates, which are found at the end junctions between two cells. Companion cells are found alongside the sieve-tube cells, providing them with metabolic support.