Tissue : Meristematic & Simple Permanent
( For class IX)
Q1 What is tissue?
A tissue can be defined as a group of cells having common origin, structure and function.
Q2 Types of tissue?
Tissues are of two types – (i) Meristematic tissue and (ii) Permanent tissue.
Q3 Meristematic tissue?
Meristematic tissues are a group of young living cells that remain in a state of continuous division to form new and newer cells.
Animals don't have Meristematic tissue.
Q4 Properties of Meristematic tissue?
(i) The cells of meristem are isodiametric in shape.
(ii) They are tightly packed with negligible intercellular spaces.
(iii) All cells of meristem are living.
(iv) The cell wall is thin and composed of cellulose only.
(v) Cells have large nuclei.
(vi) Generally vacuoles are absent, if present are very small and scattered.
(vii) Plastid and mitochondria underdeveloped.
(viii) They are located in the growing regions only.
Q5 Classify meristems on the basis of position.
According to position Meristematic tissues are of three types:
(i) Apical Meristem :- When meristematic tissues occupy apical position like shoot apex, root apex or leaf apex, they are termed as Apical Meristem.
Function : By the activity of the apical meristems the plant body grows in length.
(ii) Intercalary Meristem :- The meristems located at the base of internode and have permanent tissue below and above are called Intercalary Meristem . It remains widely separated from apical meristems .
Function: The derivatives of Intercalary Meristem differentiate into permanent tissues , as a result stem internode elongates.
(iii) Lateral Meristem :- The meristems located parallel to the long axis of root and shoot of Dicotyledons and Gymnosperms are called Lateral Meristems .
Function:- These tissues increase the girth of the plant body.
Q6 Permanent tissues ?
The fully differentiated mature cells which cannot divide further are called Permanent tissues.
Q7 Types of Permanent tissues?
Two types:
(I) Simple Permanent tissues and
(II) Complex Permanent tissues
Q8 Simple Permanent tissues?
The tissues, which are composed of one type of fully differentiated non-dividing cells, are called Simple Permanent tissues.
Q9 Types of Simple Permanent tissues?
Three types:
Parenchyma
Collenchyma and
Sclerenchyma
Q10 Parenchyma?
Fig: Parenchyma cells
The plant tissues composed of only one type of non- dividing living cells with live nucleate protoplast and thin cellulosic cell wall are called parenchyma.
Properties/ Characteristics:
(i)All cells are living.
(ii) Cells are generally oval, polygonal and spherical in shape .
(iii) Intercellular spaces present.
(iv)The cell wall is thick or thin, made up of cellulose only.
Types :
(i) Normal type:
In this type, cells are isodiametric and present in the epidermis, cortex, endodermis , pith and ground tissue.
(ii) Chlorenchyma:
These are chloroplasts containing parenchyma present in green parts of a plant. There are two types of such tissues in leaves :-
Palisade parenchyma: Elongated green cells without intercellular spaces.
Spongy parenchyma: Round or oval green cells with intercellular spaces.
Fig: Leaf T.S. showing Chlorenchyma
(iii) Aerenchyma:
Parenchyma with large air cavities to provide buoyancy and to help in gas exchange. Generally present in aquatic plants.
Fig: T.S. of Nymphea petiole showing Aerenchyma.
Functions:
(i) Stores foods and water.
(ii) Parenchyma of epidermis protects inner tissues.
(iii) Chlorenchyma performed photosynthesis.
(iv) Aerenchyma helps buoyancy.
Q10 Collenchyma?
Collenchyma are thick walled and compactly packed( without any intercellular space due to deposition of pectin at corners) living simple permanent tissues with relatively more thick corners.
Properties:
(i) Cellwall is made up of cellulose and pectin.
(ii) Cells are living, elongated and have irregularly thick cell walls at corners.
(iii) Intercellular spaces are filled by the deposit of thickening materials.
Distribution:
(i) Below the epidermis (as hypodermis) in stems of non- woods dicotyledons, leaves and petioles.
(ii) Present in leaf stalks ( below the epidermis).
(iii) Absent in roots , monocotyledonous stems and leaves.
Functions:
(i) Provide plasticity/ flexibility and mechanical strength like bending of tendrils and stems of a climber plant.
(ii) If green, perform photosynthesis.
Fig: A T.S. of stem showing different types of plant tissues.
Q11 Sclerenchyma?
Sclerenchyma is the simple permanent tissue of lignified dead cells with pointed ends and without intercellular spaces. Sclerenchyma are also called fibres.
Properties:
Cell wall materials: cellulose and lignins.
Intercellular spaces absent.
Simple pits present.
Distribution: Occurs in stems as hypodermis, pericycle, above or around the vascular bundles, in the veins of leaves, in xylem and phloem, hard covering of seed and nuts too.
Functions:
(i) Since it is lignified,it provides mechanical strength to plant parts to bear compression, pull, bending ,etc.
Q12 Differences:
Parenchyma | Collenchyma | Sclerenchyma |
Living cells. Cell wall thin Cell wall component : Cellulose only. Intercellular spaces present.
| Living cells. Cell wall thick. Cell wall component: Cellulose and Pectin. Intercellular spaces thickened due to pectin deposition.
| Dead cells. Cell wall thick. Cell wall component: Cellulose and Lignins. Intercellular spaces nil.
|
Q13 Sclerides?
Sclerides are highly thickened and lignified short sclerenchyma present in seed- coat ( Pisum) flesh of hard fruits(Pyrus) and shell , leaves of Camellia , etc.
Q.14 What do you mean by epidermis?
The outermost layer of a plant is generally made up of a single layer of parenchyma and called epidermis.
Q.15 Properties of epidermis?
(i) Generally epidermis is unilayered.
(ii) Most epidermal cells are flat.
(iii) The outer and lateral walls of epidermal cells are thicker than the inner wall.
(iv) Epidermis of dorsal surface of dorsiventral leaf , desert plant ,etc. has waxy coating of cutin to prevent water loss.
(v) In leaf epidermis is punctured by stomata.
Q.16. What is a stoma?
A stoma is a tiny pore present in leaf epidermis. It is enclosed by two Kidney- shaped guard cells.
Q.17. Functions of Stomata?
(i)Stomata are those pores through which exchange of CO2 and O2 take place.
(ii) Transpiration in plants takes place through stomata.
Q18. What is cork?
A cork is a multilayered dead and compactly arranged suberin containing permanent tissue obtained from the activity of a secondary meristem present in the cortex of plants having secondary growth.
Q19 Functions of cork?
Cork prevents entry and exit of water and gases through injured critical cells of dicot plants showing secondary growth.
Q 20 Why is cork impervious to gases and water?
It is due to the presence of suberin.
Q 21 Differentiate stem hair and root hair.
Stem hair:
(i) Stem hair is multicellular .
(ii) It is not a part of an epidermal cell.
Root hair:
(i) Unicellular.
(ii) It is the part of epidermis as the outer wall of an epidermal cell extends as a tube to form a root hair.
MCQ
1.Cambium is
(a) Apical meristem
(b)Intercalary meristem
(c )Lateral meristem
(d) None of the above
2.Apical meristems are located at the
(a) Apex of stem only
(b) Apex of root only
(c ) Both of shoot and root apex
(d) All of the above
3.Cell walls of plant meristems are composed of
(a)Cellulose only
(b) Cellulose and pectin
(c) Cellulose and lignins
(d)Pectin and lignins
4.Chlorenchyma is a kind of
(a)Thin walled living cell
(b)Simple permanent tissue
(c)Chloroplast containing cell
(d)All of the above
5 Bending of tendrils in cucumber is provided by
(a)Parenchyma
(b)Collenchyma
(c )Sclerenchyma
(d)Aerenchyma
6. The plant tissue having dead cells is
(a)Parenchyma
(b)Collenchyma
(c )Sclerenchyma
(d)Chlorenchyma
7.Generally epidermis is
(a)Unilayered
(b)Bilayered
(c) Multilayered
(d)None of the above
8. Cork cells are
(a)Dead and without intercellular space
(b) Dead with intercellular space
(c )Living without intercellular spaces
(d) Living with intercellular spaces
9. A stomata is guarded by
( a)1 cell
(b)2 cells
(c )3 cells
(d)4 cells
10. Lignins is found in
(a)Plant meristems
(b)Parenchyma
(c )Collenchyma
(d)Sclerenchyma
Answers
1 C 2 C 3 A. 4 D. 5 B. 6 C. 7 A. 8 A 9 B 10 D
Tissue : Meristematic & Simple Permanent
( For class IX)
Q1 What is tissue?
A tissue can be defined as a group of cells having common origin, structure and function.
Q2 Types of tissue?
Tissues are of two types – (i) Meristematic tissue and (ii) Permanent tissue.
Q3 Meristematic tissue?
Meristematic tissues are a group of young living cells that remain in a state of continuous division to form new and newer cells.
Animals don't have Meristematic tissue.
Q4 Properties of Meristematic tissue?
(i) The cells of meristem are isodiametric in shape.
(ii) They are tightly packed with negligible intercellular spaces.
(iii) All cells of meristem are living.
(iv) The cell wall is thin and composed of cellulose only.
(v) Cells have large nuclei.
(vi) Generally vacuoles are absent, if present are very small and scattered.
(vii) Plastid and mitochondria underdeveloped.
(viii) They are located in the growing regions only.
Q5 Classify meristems on the basis of position.
According to position Meristematic tissues are of three types:
(i) Apical Meristem :- When meristematic tissues occupy apical position like shoot apex, root apex or leaf apex, they are termed as Apical Meristem.
Function : By the activity of the apical meristems the plant body grows in length.
(ii) Intercalary Meristem :- The meristems located at the base of internode and have permanent tissue below and above are called Intercalary Meristem . It remains widely separated from apical meristems .
Function: The derivatives of Intercalary Meristem differentiate into permanent tissues , as a result stem internode elongates.
(iii) Lateral Meristem :- The meristems located parallel to the long axis of root and shoot of Dicotyledons and Gymnosperms are called Lateral Meristems .
Function:- These tissues increase the girth of the plant body.
Q6 Permanent tissues ?
The fully differentiated mature cells which cannot divide further are called Permanent tissues.
Q7 Types of Permanent tissues?
Two types:
(I) Simple Permanent tissues and
(II) Complex Permanent tissues
Q8 Simple Permanent tissues?
The tissues, which are composed of one type of fully differentiated non-dividing cells, are called Simple Permanent tissues.
Q9 Types of Simple Permanent tissues?
Three types:
Parenchyma
Collenchyma and
Sclerenchyma
Q10 Parenchyma?
The plant tissues composed of only one type of non- dividing living cells with live nucleate protoplast and thin cellulosic cell wall are called parenchyma.
Properties/ Characteristics:
(i)All cells are living.
(ii) Cells are generally oval, polygonal and spherical in shape .
(iii) Intercellular spaces present.
(iv)The cell wall is thick or thin, made up of cellulose only.
Fig: T.S. of a stem showing parenchyma cells.
Types :
(i) Normal type:
In this type, cells are isodiametric and present in the epidermis, cortex, endodermis , pith and ground tissue.
(ii) Chlorenchyma:
These are chloroplasts containing parenchyma present in green parts of a plant. There are two types of such tissues in leaves :-
Palisade parenchyma: Elongated green cells without intercellular spaces.
Spongy parenchyma: Round or oval green cells with intercellular spaces.
Fig: Leaf T.S. showing Chlorenchyma
(iii) Aerenchyma:
Parenchyma with large air cavities to provide buoyancy and to help in gas exchange. Generally present in aquatic plants.
Fig: T.S. of Nymphea petiole showing Aerenchyma.
Functions:
(i) Stores foods and water.
(ii) Parenchyma of epidermis protects inner tissues.
(iii) Chlorenchyma performed photosynthesis.
(iv) Aerenchyma helps buoyancy.
Q10 Collenchyma?
Collenchyma are thick walled and compactly packed( without any intercellular space due to deposition of pectin at corners) living simple permanent tissues with relatively more thick corners.
Properties:
(i) Cellwall is made up of cellulose and pectin.
(ii) Cells are living, elongated and have irregularly thick cell walls at corners.
(iii) Intercellular spaces are filled by the deposit of thickening materials.
Distribution:
(i) Below the epidermis (as hypodermis) in stems of non- woods dicotyledons, leaves and petioles.
(ii) Present in leaf stalks ( below the epidermis).
(iii) Absent in roots , monocotyledonous stems and leaves.
Functions:
(i) Provide plasticity/ flexibility and mechanical strength like bending of tendrils and stems of a climber plant.
(ii) If green, perform photosynthesis.
Fig: A T.S. of stem showing different types of plant tissues.
Q11 Sclerenchyma?
Sclerenchyma is the simple permanent tissue of lignified dead cells with pointed ends and without intercellular spaces. Sclerenchyma are also called fibres.
Properties:
Cell wall materials: cellulose and lignins.
Intercellular spaces absent.
Simple pits present.
Distribution: Occurs in stems as hypodermis, pericycle, above or around the vascular bundles, in the veins of leaves, in xylem and phloem, hard covering of seed and nuts too.
Functions:
(i) Since it is lignified,it provides mechanical strength to plant parts to bear compression, pull, bending ,etc.
Q12 Differences:
Parenchyma
Collenchyma
Sclerenchyma
Living cells.
Cell wall thin
Cell wall component : Cellulose only.
Intercellular spaces present.
Living cells.
Cell wall thick.
Cell wall component: Cellulose and Pectin.
Intercellular spaces thickened due to pectin deposition.
Dead cells.
Cell wall thick.
Cell wall component: Cellulose and Lignins.
Intercellular spaces nil.
Q13 Sclerides?
Sclerides are highly thickened and lignified short sclerenchyma present in seed- coat ( Pisum) flesh of hard fruits(Pyrus) and shell , leaves of Camellia , etc.
Q.14 What do you mean by epidermis?
The outermost layer of a plant is generally made up of a single layer of parenchyma and called epidermis.
Q.15 Properties of epidermis?
(i) Generally epidermis is unilayered.
(ii) Most epidermal cells are flat.
(iii) The outer and lateral walls of epidermal cells are thicker than the inner wall.
(iv) Epidermis of dorsal surface of dorsiventral leaf , desert plant ,etc. has waxy coating of cutin to prevent water loss.
(v) In leaf epidermis is punctured by stomata.
Q.16. What is a stoma?
A stoma is a tiny pore present in leaf epidermis. It is enclosed by two Kidney- shaped guard cells.
Q.17. Functions of Stomata?
(i)Stomata are those pores through which exchange of CO2 and O2 take place.
(ii) Transpiration in plants takes place through stomata.
Q18. What is cork?
A cork is a multilayered dead and compactly arranged suberin containing permanent tissue obtained from the activity of a secondary meristem present in the cortex of plants having secondary growth.
Q19 Functions of cork?
Cork prevents entry and exit of water and gases through injured critical cells of dicot plants showing secondary growth.
Q 20 Why is cork impervious to gases and water?
It is due to the presence of suberin.
Q 21 Differentiate stem hair and root hair.
Stem hair:
(i) Stem hair is multicellular .
(ii) It is not a part of an epidermal cell.
Root hair:
(i) Unicellular.
(ii) It is the part of epidermis as the outer wall of an epidermal cell extends as a tube to form a root hair.
Exercise
MCQ
1.Cambium is
Apical meristem
Intercalary meristem
Lateral meristem
None of the above
2.Apical meristems are located at the
Apex of stem only
Apex of root only
Both of shoot and root apex
All of the above
3.Cell walls of plant meristems are composed of
Cellulose only
Cellulose and pectin
Cellulose and lignins
Pectin and lignins
4.Chlorenchyma is a kind of
Thin walled living cell
Simple permanent tissue
Chloroplast containing cell
All of the above
5 Bending of tendrils in cucumber is provided by
Parenchyma
Collenchyma
Sclerenchyma
Aerenchyma
6. The plant tissue having dead cells is
Parenchyma
Collenchyma
Sclerenchyma
Chlorenchyma
7.Generally epidermis is
Unilayered
Bilayered
Multilayered
None of the above
8. Cork cells are
Dead and without intercellular space
Dead with intercellular space
Living without intercellular spaces
Living with intercellular spaces
9. A stomata is guarded by
1 cell
2 cells
3 cells
4 cells
10. Lignins is found in
Plant meristems
Parenchyma
Collenchyma
Sclerenchyma
Answers
1 C 2 C 3 A. 4 D. 5 B. 6 C. 7 A. 8 A 9 B 10 D
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