Plant Tissue

Question 1

Define—Tissue

Answer 1

Tissue is a group of similar cells having a common origin and performing a specific function.

Question 2

What are the 2 types of plants tissues?

Answer 2

In plants, there are basically 2 types of tissues—Meristematic and Permanent.

Question 3

Write the characteristic structure of Meristematic tissue.

Answer 3

• Meristematic tissue are composed of cells that have the
  power of dividing.
• The cells are small, spherical, oval or polygonal.
• Inter cellular spaces are absent.
• Each cell contains a large prominent nucleus.
• Protoplasm is abundant. Hence vacuoles are lacking.

Question 4

Explain the types of Meristems.

Answer 4

According to their location in the plant, Meristems are of 3 types :—

Location, Function

1. Apical–At the growing tip of Stems and
   Roots

Brings about the elongation of the Root and
Stem.

2. Lateral– Found beneath the bark Brings about increase in diameter of Stem.
3. Intercalary–Located at the base of the
   internode.

Brings about development of branches.

Question 5

What are Simple permanent tissue?

Answer 5

Simple Permanent Tissue—are the mature cells, formed from meristematic cells after

differentiation-

Question 6

What are the types of Simple permanent tissue?

Answer 6

i) Parenchyma, ii) Collenchyma, iii)Sclerenchyma

Question 7

Write the structure of parenchyma.

Answer 7

Parenchyma— Structure—
* Consists of living cells.
* The cells are isodiametric, generally
spherical.
* The cell wall is thin, made up of cellulose.
* Cytoplasm present with large vacuoles.
* Intercellular spaces present.

Question 8

Write the location and function of
parenchyma.

Answer 8

Location—Found in the Cortex of stem and roots and in mesophyll of leaves.
Function—Stores food for the plant.

Question 9

Write the structure, location and function of Chlorenchyma

Answer 9

If chloroplasts are present in
parenchyma, the tissue is called
Chlorenchyma.
Location–These occur in mesophyll of
leaves.

Function—Performs photosynthesis.

Question 10

Write the structure, location and function of Aerenchyma.

Answer 10

• It is modification of parenchyma cells, containing air spaces
• Location: Found in aquatic plants
• Function: It helps the plant to float in water

Question 11

Write the structure of Collenchyma
Collenchyma— Structure—

Answer 11

• Living cells with nucleus.
• Intercellular spaces are thickened with Pectin.
• Cell wall, made up of cellulose.

Question 12

Write the location and function of Collenchyma.

Answer 12

• Location—Found in the cortex of dicot stems, in the leaf stalk.
  (Absent in monocot stems, roots and leaves.)
• Function—Gives mechanical support and flexibility to the plant part, when specially found in creepers .

Question 13

Write the structure of Sclerenchyma.

Answer 13

Structure—
* Consists of dead cells.
* Cell walls are thickened with lignin.
* Intercellular spaces are absent.

Question 14

Write the location and function of Sclerenchyma.

Answer 14

Location— Found in the stems, veins of leaves, hard coverings of nuts and seeds.

Function— Gives mechanical strength and rigidity to the plant part.

Question 15

What are the 2 types of Sclerenchyma?

Answer 15

Sclerenchyma is of 2 types.
i) Sclerenchyma fibres— Made up of long, elongated narrow cells with
tapering ends. Eg—Coconut fibres, hemp, jute fibres, etc.

ii) Sclereids / Stone cells— Found in the pulp of certain fruits like Pears, Sapota, Guava, etc.

Question 16

What are the complex permanent tissue? Or Conducting tissue?

Answer 16

The complex permanent tissues are those which have different structures, but same function i.e. they
are the vascular tissues (Conducting tissues) which provides passage for the water and dissolved
materials to move up and down the plant.

Question 17

Explain the different elements of xylem.

Answer 17

The Xylem Tissue is composed of 4 elements—- Tracheids, Vessels, Xylem Parenchyma and Xylem
Fibres.
a) Tracheids—A tracheid is an elongated cell with tapering end walls, thickened with lignin.
b) Vessels—Are cylindrical tube-like structures formed by row of cells, placed end to end.
c) Xylem Parenchyma—Parenchyma cells associated with Xylem.
d) Xylem Fibres–Sclerenchyma fibres associated with Xylem.

Question 18

Give the location and function of Xylem

Answer 18

Location— Found in the vascular bundle of stems, roots and leaves. (They occur together with
Phloem to form the Vascular Bundle)

Function—Conducts water and minerals from the roots to all parts of the plants (especially to leaves,
in upward direction)

Question 19

Explain the elements of Phloem.

Answer 19

Structure—Phloem consists of 4 elements—Sieve Tubes,
Companion Cells, Phloem Parenchyma and Phloem Fibres.
a) Sieve Tubes—Elements made up of thin walled
elongated cells, placed end to end forming tube like
structures.
b) Companion Cells— Found next to the Sieve tube,
containing dense cytoplasm.
c) Phloem Parenchyma— Parenchyma cells associated
with Phloem.
d) Phloem Fibres—Sclerenchyma fibres associated with
Phloem.

Question 20

Give the location and function of Phloem..

Answer 20

Location—Found in the vascular bundle of stem, roots and leaves.

Function— Conducts prepared food from leaves to all parts of the plant.