Question

	Translocation
What is transported?
In xylem or phloem?
Direction of flow
Cells involved (note alive or dead, which plant groups have them, function)	Sieve tube elements:
	Companion cells:
Does this process require the plant to expend energy?

Answer 1

What is transported

Xylem - transport of water and some dissolved compunds from the roots to stems and leaves

Phloem - transport of food from photosynthetic parts of the plant like leaves to roots and stems.

Direction of flow

Xylem - unidirectional,  always upward, water from roots reaches the leaves and evaporates.

Phloem - Bidirectional depending on the concentrations of the solutes in the phloem.

Companion cells are present in then phloem of flowering plants and carries out the metabolic activities of the sieve tube elements, without the companion cells the sieve tube elements degenerates and the phloem stops functioning leading to the death of the plant.

Sieve tube elements are involved in transporting necessary molecules across the plant and functions along with companion cells for example the sieve tube elements are involved in transporting carbohydrates to all parts of the plant.

Translocation process needs the plant to expend energy since it is a process involved in transporting materials across the plant and since this is an active process it requires energy.