Question

WRITE SHORT NOTES ON PHLOEM​

Answer 1

$\textbf{Phloem}$:

It contains tubes but has no mechanical function.

It consists of the following four type of cells :

1. $\textbf{Sieve Tubes }$:

These are slender, tube like structure bounded by thin walled cells.

2. $\textbf{Companion cells }$:

Generally associated with the sieve tubes is a small child containing dense and very active cytoplasm and large elongated nucleus.

3. $\textbf{ Phloem Parenchyma }$

4. $\textbf{Phloem Fibres }$

Answer 2

PHLOEM

Phloem is type of complex permanent tissue which conducts food materials from the leaves to other parts of the plant. This a type of permanent tissue which do not provide any mechanical strength to plant.

Below are some types of phloem :-

• Sieve tubes :-  Sieve tubes are conducting elements which are elongated and are of tube-like structures. The sieve tube cells consist no nucleus and have a large vacuole.

• Companion cells :-  Companion cells are parenchymatous cells which are closely associated with the sieve tube. As these cells have nucleus so it controls metabolic activities of sieve tubes.

• Phloem parenchyma :-  Phloem parenchyma are long and cylindrical cells and have a dense cytoplasm and nucleus. It helps to store the food in it.

• Phloem fibers :- Phloem fibers are sclerenchymatous cells which means they are non-living. As they are made of sclerenchymatous cells then they have thick cell walls and offers mechanical strength.