HORTICULTURE

Detailed explanation-1: -The phloem is composed of three types of cells – the conducting cells, the parenchyma cells and the supportive cells. The conducting cells, also called sieve elements, are composed of columns of sieve tube cells that have perforations in their lateral walls and that helps in the conduction of food throughout the plant.

Detailed explanation-2: -Sieve tube elements, parenchyma, sclerenchyma (bast fibres) and companion cells are components of phloem.

Detailed explanation-3: -It has four elements, namely, companion cells, sieve tubes, phloem parenchyma, and phloem fibres.