Question

Describe the structure of a phloem tissue

Answer 1

Phloem tissue consists of conducting cells, generally called sieve elements, parenchyma cells, including both specialized companion cells or albuminous cells and unspecialized cells and supportive cells, such as fibres and sclereids.

Answer 2

ANSWER.....


☆☆ PHLOEM ☆☆

---- Phloem consists of sieve tube elements, companion cells, phloem fibres, phloem parenchyma.

------ Phloem Transport the food material from leaves to various parts of the plant.



¤¤ Sieve Tube Elements.
▪ Long tube like structures arranged longitudinally.
▪ Associated with companion cells.
▪ End walls are performed to form sieve plates.
▪ Functions of sieve tube are controlled by the nucleus of companion cells.


¤¤ Companion Cells
▪ Specialised parenchyma cells associated with sieve tube elements.
▪ Connected with the sieve tube elements by pit fields present between their common longitudinal walls.
▪ They help to maintain pressure gradient in sieve tubes.


¤¤ Phloem Parenchyma
▪ Made up of elongated, tapering cylindrical cells with dense cytoplasm and nucleus.
▪ Cell wall made up of cellulose with the pits through which plasmodesmatal connections exist between cells.
▪ Store food material.


¤¤ Phloem Fibres [ Bast Fibres ]

▪ They are sclerechymatous; absent in primary phloem but present in secondary phloem.
▪ They are elongated, unbranched pointed, needle like apices with thick cell walls.

## Protophloem :- First formed phloem with narrow sieve tubes.

## Metaphloem :- Later formed phloem with bigger sieve tubes.