Phloem

Question 1

function of Phloem

Answer 1

Transports food material

usually from leaves to other parts of the plant.

Question 2

Phloem in angiosperms is composed of

Answer 2

Sieve tube elements , companion cells , phloem parenchyma and phloem fibers

Question 3

Gymnosperm

Answer 3

albuminous cells and sieve cells

Question 4

What elements of pholem gymnosperm lack

Answer 4

Sieve cells and companion cells

Question 5

Structure of sieve tube elements

Answer 5

Sieve tube elements are also long , tube like structures , arranged longitudinally and associated with the companion cell

Question 6

Sieve plates

Answer 6

Sieve tube end walls are perforate in sieve like manner to form the sieve plates

Question 7

In gynosperm which one lack nucles

Answer 7

A mature sieve element possesses a peripheral cytoplasm and large vacuole but lacks a nucles.

Question 8

function sieve tubes are controlled by..

Answer 8

Companion cells

Question 9

Companion cells

Answer 9

The companion cells are specialised parenchymatous cells, which are closely associated with sieve tube element .

Question 10

Companion cells and sieve tubes are connected

Answer 10

The sieve tube elements and companion cells are connected by pit fields present between their common longitudinal

Question 11

Function of sieve tubes

Answer 11

The companion cells help in maintaining the pressure gradient in the sieve tubes

Question 11

Phloem parenchyma is made up

Answer 11

Elongated, tapering cylindrical cells which have dense cytoplasm and nucleus

Question 12

Cell wall of Phloem parenchyma

Answer 12

The cell wall composed of cellulose and has pits through which plasmodesmatal connection between cell

Question 13

Phloem Parenchyma function

Answer 13

The companion cells store food material and other substances like resins latex and mucilage.

Question 14

Structure of Phloem fibers

Answer 14

These are much elongated , unbranched and have pointed needle like apices.
The cell wall of phloem fibers are quite thick

Question 14

Phloem parenchyma absent in

Answer 14

most of the monocotyledons cells

Question 15

Phoem fiber

Also known as bast fibers

Answer 15

made up of sclerenchymatous cells

Question 15

Phloem fiber present in

Answer 15

Generally present in secondary phloem and absent in primary phloem

Question 16

At maturity … Phloem fibers

Answer 16

At maturity , these fibers lose their protoplasm and became dead

Question 17

Use of

Phloem fibers

Answer 17

Phloem fibres of jute, flax and hemp are used commercial

Question 18

Protophloem

Answer 18

The first formed primary phloem consists of narrow sieve tubes referred to as protophloem

Question 19

Metaphloem

Answer 19

The later formed phloem has bigger sieve tubes and is reffed to as metaphloem