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Introduction

Introduction

  • All living organisms are made up of cells.
  • They can be unicellular or multicellular.

  • A unicellular organism has a single cell in its body, i.e., a single cell performs all basic life activities. For example: - Amoeba, euglena, bacteria etc

                

Amoeba                        Euglena

Bacteria

  • In multicellular organisms (e.g., a human being) there are millions of cells.
  • Most of these cells are specialised to carry out a few functions efficiently.
  • These cells are organized as tissue, organ and organ system so as form an organism.

  • The different functions are taken up by different groups of cells.
  • This property of distribution of work in different cells, tissue or organ is known as division of labour. For example, in human beings, muscle cells contract and relax to cause movement of a body part, nerve cells or neurons carry messages, blood flows to transport oxygen, food, hormones and waste materials.

Sr. No.

Tissue

Function

1

Muscular

Movement

2

Nervous

Transmits messages

3

Blood

Transports material

 

 

Tissue

  • A group of cells similar in structure that work together to perform a particular function forms a tissue.

Tissues can be of two kinds mainly:       Plant Tissue,       Animal Tissue

  • Plants are autotrophic and stationary whereas animals are heterotrophic and can move from one place to another for various purposes. Hence plants need less energy as compared to animals.
  • Thus, in plants most of the tissues are supportive so as to provide mechanical strength.
  • Also, most of the tissues are dead in plants so it can be said that plants are made up of living as well as non living tissues so as to perform basic metabolic reactions and to provide them strength.
  • While in animals almost all tissues are living as they need a constant supply of energy.

Comparison of plant and animal tissues:

Plant tissues

Animal tissues

  • Tissues are designed on the basis of its stationary habit and autotrophic mode of nutrition.
  • Tissues are designed on the basis of its high mobility habit and heterotrophic mode of nutrition
  • Plants are made up of more dead supportive tissues.
  • Dead tissues are less common.
  • They need less maintenance energy so the ratio of living tissue is low.
  • They need constant supply of energy so most of the tissues in them are living.
  • There is differentiation of tissues into meristematic and permanent on the basis of cell dividing capacity.
  • Cell division capacity is uniform so no such differentiation is observed.
  • Meristematic tissue support the increase in height of the plant as well as primary and secondary growth throughout their life.
  • Animals do not show increase in height after reaching maturity but repairable and secondary growth takes place in a controlled manner.
  • Organization of plant tissue is simple.
  • Organization of tissue in animals is complex with development of organ and organ systems.

 

Plant Tissue

  • Plant tissues are classified on the basis of its cell division capacity and living/ dead nature into meristematic and permanent tissue.

Meristematic tissue:   leaf

Permanent tissue: bark of the tree coconut shell

 

  • They are sub-divided on the basis of its location and composition, i.e., the cells are of same type or different.

 

Meritematic Tissues (Meristems)

Nature:

  • Cells of meristems divide continuously and help in increasing the length and girth of the plant.

 

Characteristics of Meristematic tissues (meristems)

Growth

  • Cells of meristems divide continuously and help in increasing the length and girth of the plant.

Structure

  • The cells of meristematic tissue are similar in structure and have thin cellulose cell walls.

Shape

  • They may be spherical, oval, polygonal or rectangular.

Intercellular space

  • They are compactly arranged and do not contain any intercellular space between them.

Cytoplasm and nucleus

  • Each cell contains dense or abundant cytoplasm and a single large nucleus.

Vacuole

  • These cells contain few vacuoles or no vacuoles at all.

 

Occurrence:

  • Meristematic tissues are growth tissues and are found in those regions of the plant that grow.
  • Sub types of meristematic tissues:- According to their position in the plant, there are three types of meristems. They are:-
    1. Apical
    2. Lateral and
    3. Intercalary

 

Apical meristems:

  • These are situated at the growing tip of stems and roots, i.e., at shoot apex and root apex.
  •  Apical meristems are also found at apices of the leaves.

 

Lateral meristems:

  • These are found beneath the bark (called cork cambium) and in vascular bundles of dicot roots and stems (called cambium).
  • They occur in thin layers.
  • Cambium is the region which is responsible for growth in thickness.

 

Intercalary meristems:

  • They are located at the base of leaves or internode, e.g., stems of grasses and other monocots.

Functions of meristematic tissues:

  • The main function of meristematic tissue is to divide continuously and form new cells.
  • They help in the generation of leaves, branches, flowers etc.
  • They participate in repairing the damaged tissue.

 

Different types of meristems have the following functions:

Apical meristems:

  • It brings about the elongation of the root and stem.
  • It results in increase in the height of the plant, which is called primary growth.

Lateral meristem:

  • It causes the organ (stem or root) to increase in diameter and girth. This is called secondary growth.

 

Intercalary meristem:

  • It produces an increase of length of organ.
  • It maintains the upright position of stem or shoots.

 

Questions

(A)    Fill in the blank :

  1. A group of cells similar in structure that work together to perform a particular function forms a ________.

Ans:  Tissue

  1. Plants shows ________ mode of nutrition while animals shows ________ mode of nutrition.

Ans: autotrophic, heterotrophic

  1. In plants, most of the tissues are ________ so as to provide mechanical strength.

Ans:  supportive

  1. Dead tissues in plants provide ________ while living cells perform ________functions.

Ans: strength, metabolic

  1. In animals, almost all tissues are________ as they need a constant supply of energy.

Ans:  living

  1. The cells of ________ tissue have thin cellulose cell walls.

Ans:  meristematic

  1. ________ meristems brings about the elongation of the root and stem.

Ans:  apical

  1. ________ meristem are found beneath the bark.

Ans:  lateral

  1. ________ meristem causes the organ (stem or root) to increase in diameter and girth.

Ans: lateral

  1. Meristematic Tissues are also called ________.

Ans:  Meristems

  1. The meristematic cells in plants are ________ arranged and do not contain any intercellular space between them.

Ans:  compactly

  1. The ________ cells of plant contain few vacuoles or no vacuoles at all.

Ans:  Meristematic

  1. Meristematic tissues supports ________ of the plants.

Ans:  growth

  1. Primary growth of plant is due to ________ meristem.

Ans:  Apical

  1. Secondary growth of plant is due to ________ meristem.

Ans:  Lateral

  1. ________ meristem produces an increase of length of organ.

Ans:  Intercalary

  1. ________ meristem are located at the base of leaves or internode.

Ans:  Intercalary

  1. ________ tissues are derived from the meristematic tissues.

Ans:  Permanent

  1. ________ is the region which is responsible for growth in thickness.

Ans:  Cambium

  1. The main function of ________ tissue in plant is to continuously form a number of new cells.

Ans:  Mersistematic

  1. Property of rapid cell division and forming a mass of same type of cells is known as ____.

Ans: totipotency

 

(B)    State whether the following statement is true or false. If false then state the correct statement:

  1. Cells of meristems divide continuously and help in increasing the length and girth of the plant.

Ans: True

  1. The cells of meristematic tissue are similar in structure and have thick cellulose cell walls.

Ans: False; The cells of meristematic tissue are similar in structure and have thin cellulose cell walls.

  1. The meristematic cells are compactly arranged and do not contain any intercellular space between them.

Ans:  True

  1. According to their position in the plant, meristems are apical, lateral and intercalary.

Ans: True

  1. Lateral meristems are situated at the growing tip of stems and roots.

Ans:  False, Apical meristems are situated at the growing tip of stems and roots

  1. Apical meristems are found at apices of the leaves.

Ans:  True

  1. Lateral meristems are found beneath the bark and in vascular bundles of dicot roots and stems.

Ans:  True

  1. Intercalary meristems are located at the apex of root and stem.

Ans:  False; Intercalary meristems are located at the base of leaves or internode.

  1. Intercalary meristems cause primary growth.

Ans:  False; Apical meristems cause primary growth.)

  1. The cells of meristematic tissues have prominent vacuoles and a small nucleus.

Ans:  False; The cells of meristematic tissues have prominent nucleus and small vacuoles.

 

(C)     Match the following:

  1.  

 

Column A

 

Column B

1.

Meristematic tissue

A.

Present on shoot apex and root apex

2.

Permanent tissue

B.

Protective and supporting tissue

3.

Apical meristem

C.

Mature cells incapable of cell division

4.

Simple tissue

D.

Cells have totipotency

Ans:  (1 - d), (2 - c), (3 - a), (4 - b).

  1.  

 

Column A

 

Column B

1.

Lateral meristem

A.

Produces an increase of length of organ

2.

Complex tissue

B.

Found beneath the bark

3.

Intercalary meristem

C.

Storage of food

4.

Parenchyma

D.

Made up of more than one type of cells

Ans:  (1 - b), (2 - d), (3 - a), (4 - c).

 

(D)    Multiple choice questions:

  1. Cells of ________ divide continuously and help in increasing the length and girth of the plant.

(a) Collenchyma

(b) Parenchyma 

(c) Sclerenchyma

(d) Meristems

Ans:  (d)

  1. Primary tissues of a plant

(a) add to the length of roots and shoots

(b) add to the diameter of existing roots and shoots

(c) are only in the embryo

(d) are only in the seedling.

Ans:  (a)

  1. The function of cell division is restricted to

(a) meristematic cells 

(b) permanent cells

(c) secretory cells

(d) all of the above

Ans:  (a)

  1. The most abundant matter of the middle lamellae of the plant cells is

(a) calcium                    (b) pectin

(c) cutin                         (d) both a and b

Ans:  (d)

  1. How can you justify the cambium to be a lateral meristem?

(a) It forms lateral branches

(b) Increases height and diameter

(c) Adds to plant girth

(d) Forms lateral appendages.

Ans:  (b)

  1. Meristematic tissues are found in

(a) only stems of the plants 

(b) both roots and stems

(c) all growing tips of the plant body

(d) only roots of the plants.

Ans:  (c)

  1. Most active cell divisions occur in cells of

(a) xylem

(b) phloem

(c) apical meristem

(d) none of the above.

Ans:  (c)

  1. Meristematic cells contain

(a) thin homogenous cell wall

(b) dense cytoplasm

(c) large nuclei

(d) all of the above.

Ans:  (d)

  1. Group of cells with same origin and function is

(a) organ                       (b) simple tissue

(c) any tissue                (d) compound tissue

Ans:  (c)

  1. Girth of the plant increases due to

(a) Apical meristem

(b) Lateral meristem

(c) Intercalary meristem

(d) None

Ans:  (b)

 

(E)     Identify the following type of tissue:

  1. Name the term for a group of cells similar in structure that work together to perform a particular function forms.

Ans: Tissue

  1. Which plant cells have capacity to divide continuously?

Ans:  Meristematic

  1. Mersitematic tissue situated at the growing tip of stems and roots.

Ans:  Apical meristems

  1. Which meristematic tissue is responsible for primary growth of plant body?

Ans:  Apical meristems

  1. Meristematic tissue is responsible for secondary growth of plant body?

Ans:  Lateral meristems

  1. Meristematic tissue is responsible for increase of length of organ.

Ans:  Intercalary meristems

  1. Tissues are derived from the meristematic tissues but their cells have lost the power of division and have attained their definite forms.

Ans:  Permanent Tissues

  1. Which plant cell does not have vacuoles?

Ans:  Meristematic

 

Permanent Tissues

  • These tissues are derived from the meristematic tissues but their cells have lost the power of division and have attained their definite forms. Permanent tissues are classified into two types–
  1. simple
  2. complex.

 

Simple Permanent Tissues

  • These tissues are composed of cells which are structurally and functionally similar.
  • Thus, these tissues are all made of one type of cells.
  • There are different types of simple permanent tissues. They are – parenchyma, collenchyma and sclerenchyma.

 

Parenchyma:

Nature:

  • Shape – polygonal , generally oval or spherical
  • Cell wall – Thin cellulose, cell wall
  • Nucleus-Nucleus present (living cells)
  • Vacuole – Single large vacuole present
  • Intercellular space – Space present

Occurrence:

  • Cortex of roots
  • Ground tissue in stems
  • Mesophyll of leaves
  • Some parts of flower

Mesophyll Tissue of leaves

Function:

  • Stores food
  • Wound healing and origin of adventitious structures
  • Prepare food by photosynthesis if chloroplast present.

Specialized types of parenchyma:

(a)     Chlorenchyma:

  • Parenchymatous cells possessing chloroplast
  • It performs photosynthesis

(b)     Palisade Parenchyma:

  • Type of chlorenchyma with elongated cells.
  • Mainly found in leaves

(c)     Aerenchyma:

  • Star shaped parenchyma with radiating arms, leaving lots of air cavities
  • Found in petiole of banana and in many aquatic plants.
  • Gives buoyancy to the aquatic plants to float on surface of water.

 

Collenchyma:

Nature:

  • Shape – elongated
  • Cell wall – Cell wall unevenly thickened with cellulose in corners.

                   Cell wall rich in hemicelluloses

  • Nucleus – Nucleus present (living cells)
  • Vacuole – small
  • Intercellular space – generally absent or if present it is very little.

 

Occurrence:

  • Below the epidermis in stems.
  • Generally absent in monocot stems and leaves.

Function:

  • It provides mechanical support.
  • It provides elasticity strength and flexibility to the parts where it is present.
  • It helps in bending without breaking of various parts of plants like stem.
  • Prepares food if chloroplast present.

 

Sclerenchyma:

Nature:

  • Shape – Angular, fibres
  • Cell wall – Cell wall evenly thickened due to deposition of lignin.
  • Nucleus – Absent (dead cells)
  • Vacuole – Absent
  • Intercellular space – Absent, tightly compact.

Fibres: Long , narrow, thick and lignified, tapering at both the ends.

Sclerids: Short with very thick walls, irregular and not tapering at the end.

Occurrence:

  • Root, stems, leaves and petioles
  • Hard covering of seeds and nuts

             

Bark and coconut shell

Function:

  • It provides mechanical strength and protection.

Complex Tissue

  • Tissues which are composed of two or more types of cell performing common function are called complex tissues.
  • These are mainly conducting tissues. Also known as vascular tissues.
  • They are of two types: -

(1)     Xylem

(2)     Phloem or bast

Xylem:

 

Nature:

  • Different elements present in xylem are
  1. Tracheids:
  • Elongated cells with tapering ends.
  • Wall contains pits.
  • Meant for transport of water.
  1. Vessels or trachea:
  • Long, tubular, shorter than tracheids
  • Formed by row of cells placed end to end.
  • Transverse walls of these cells are dissolved so they form pipe like structure.
  • Transport the water to various parts of plants.
  1. Xylem fibres:
  • dead and supportive in function
  • present around the tracheids and vessels.
  1. Xylem parenchyma:
  • Living cells with developed nucleus and intercellular spaces.
  • Meant for storage of food
  • Helps in lateral transport of water and minerals.
  • All elements of xylem at maturity consist of dead cells and bound with lignified cell walls, except xylem parenchyma.

Occurrence:

  • In root, stem and leaf of higher plants.
  • They occur together with the phloem and form the vascular bundle.

Function:

  • Tracheids and vessels conduct water and minerals upwards from the roots to the stem and leaves.
  • Older xylem tissue forms the wood and do not take part in conduction but gives mechanical strength to the plant.

 

Phloem:

 

Different elements present in this complex tissue are:

  1. Sieve tubes:
  • Slender, tubular structures.
  • Cells are elongated, thin walled.
  • Walls are perforated with pores and are called as sieve plate.
  • Nucleus absent, still cells are alive.
  • Helps in connections between different cells upwards and downwards both.
  1. Companion cells:
  • Associated with sieve tubes via plasmodesmata.
  • Smaller cells with thin wall.
  • Large nucleus and dense cytoplasm present.
  1. Phloem parenchyma:
  • Living cells, have thin cell wall.
  • Meant for storage and lateral conduction of food material from leaves to sieve tubes.
  1. Phloem fibres:
  • Elongated spindle shaped dead cells with narrow lumen.
  • Cells are thick walled.
  • Provide mechanical strength to the tissue.
  • Have economical value.
  • All elements of phloem tissue consist of living cells, except phloem fibres.

Occurrence:

  • It is found in all parts of plant like roots, stems and leaves.

Function:

  • Transports food prepared by leaves to different parts where it has to be stored or to the energy requiring site.

Protective Tissues

Epidermis:

  • It is usually present in the outermost layer of the plant body such as leaves, flowers, stem and roots.
  • Epidermis is one cell thick and is covered with cuticle.
  • Cuticle is a water proof layer of a waxy substance called cutin which is secreted by epidermal cells.
  • Epidermis in desert plant like cactus is thicker so as to provide protection against external dry conditions.

 

  • In aerial parts like leaves it secretes a waxy water resistant substance so as to provide protection against excess water loss and invasion of pathogenic micro organisms.

 

  • In roots, it exclusively thin and contain hair like projection so to increase the surface area. Thus helps in better absorption of minerals and water in soil.

Root Hair

  • In leaves, epidermal layer is discontinuous forming pores called stomata surrounded by guard cells which help in photosynthesis and transpiration process.

 

  • The main function of epidermis is to protect the plant from desiccation and infection.
  •  In fact cuticle of epidermis helps to reduce water loss by evaporation from the plant surface as well as helping in preventing the entry of pathogens.

 

Stomata

  • Epidermis of a leaf is not continuous at some place due to the presence of small pores, called stomata.
  • Each stoma is bounded by a pair of specialized epidermal cells or two kidney–shaped cells called guard cells.
  •  The concave sides of these guard cells face each other and have a space in between forming stomatal opening.

 

  • All epidermal cells are devoid of chloroplast except guard cells. Thus all epidermal cells appear colorless but guard cells appear green in colour due to the presence of chloroplast.

 

  • They play important role as
    1. The stoma allows gaseous exchange to occur during photosynthesis and respiration.
    2. It also allows the escape of excess water from plants in a process called as transpiration.

 

Questions

(A)    Fill in the blanks:

  1. ________ tissues are derived from the meristematic tissues.

Ans:  Permanent

  1. Parenchyma serves as ________ storage tissue.

Ans:  Food

  1. If air cavities are present, the parenchyma tissue is called ________.

Ans:  Aerenchyma

  1. _______ tissue is characterized by the deposition of extra cellulose at the corners of the cells.

Ans:  Collenchyma

  1. _________ is a kind of simple permanent plant tissue that contains very less or no intercellular spaces.

Ans:  Collenchyma

  1. Collenchyma tissue provides mechanical ________ and ________ to the part of plant where it is present.

Ans:  support, elasticity

  1. ________ tissue helps in bending of various parts of a plant (leaf, stem) without breaking it.

Ans: Collenchyma

  1. The walls of cells of ________ are greatly thickened with deposition of lignin.

Ans:  Sclerenchyma

  1. The cell wall of plant cell when thickened with lignin is called ________.

Ans:  Lignified

  1. ________ of sclerenchyma are usually pointed at both ends and are clustered into strands.

Ans: Fibres

  1. ________ of sclerenchyma are irregular-shaped.

Ans:  Sclereids

  1. Sclereids are also called as ________.

Ans:  stone cells

  1. ________ gives strength, rigidity, flexibility and elasticity to the plant body.

Ans:  Sclerenchyma

  1. ________ enables plant body to withstand various strains.

Ans:  Sclerenchyma

  1. Lignin is a complex________.

Ans:  polysacchride

  1. The ________ tissues consist of more than one type of cells.

Ans:  Complex

  1. ________ and ________ is a vascular and mechanical tissue.

Ans:  Xylem, Phloem

 

  1. All xylem elements are dead except ________.

Ans:  parenchyma

  1. _____ of xylem are very long tube–like structures formed by a row of cells placed end to end.

Ans:  Vessels

  1. ________ of xylem are elongated cells with tapering ends.

Ans:  Trachieds

  1. ________and ________ helps in upward conduction water in plants.

Ans:  Trachieds and vessels

  1. Xylem parenchyma stores food and helps in lateral conduction of________.

Ans:  Water

  1. The main function of ________ is to carry water and mineral salts upward from the root to different parts of shoots.

Ans:  Xylem

  1. End walls of ________ are perforated by numerous pores and are called sieve plates.

Ans:  Sieve tube

  1. Phloem tissue helps in transport of ________ from leaves to different parts of the plants.

Ans: food

  1. The ________ is the upper layer in a plant tissue.

Ans:  epidermis

  1. The stomatal openings are present in lower __________of leaves.

Ans:  epidermis

  1. Stomata are surrounded by ____________.

Ans:  guard cells

  1. The waxy layer above the epidermis is called _________­­­­­­­­­­­­­­­­­­­­­­­­­­­­and it is made up of_________.

Ans: cuticle, cutin

  1. The main function of epidermis is to protect the plant from _________and _________

Ans: dessication, infection

 

(B)    State whether the following statement is true or false. If false then state the correct statement:

  1. Permanent tissues are derived from the meristematic tissues.

Ans:  True

  1. Intercellular spaces are abundant in parenchymatous tissue.

Ans:  True

  1. The main function of collenchyma is to store and assimilate food.

Ans:  False, The main function of parenchyma is to store and assimilate food.

  1. If chloroplast is present, the parenchyma tissue is called collenchyma.

Ans:  False, parenchyma containing chlorophyll is known as chlorenchyma.

  1. In hydrophytes (aquatic plants) such as Hydrilla, large air cavities are present in parenchyma to give buoyancy to the plants.

Ans:  True

  1. Parenchyma with air cavities is called aerenchyma.

Ans:  True

  1. Parenchyma is characterized by the deposition of extra cellulose at the corners of the cells.

Ans:  False, collenchyma is characterized by the deposition of extra cellulose at the corners of the cells.

  1. Collenchyma is a mechanical tissue.

Ans:  True

  1. The walls of cells of sclerenchyma are greatly thickened due to deposition of cellulose.

Ans:  False, the walls of cells of sclerenchyma are greatly thickened due to deposition of lignin.

  1. Sclereids also called grit cells.

Ans:  True

  1. The sclerenchyma is mainly mechanical and protective in function.

Ans:  True

  1. Simple tissues transport water, mineral salts (nutrients) and food material to various parts of plant body.

Ans:  False, Complex tissues transport water, mineral salts (nutrients) and food material to various parts of plant body.

  1. The main function of xylem is to carry water and mineral salts upward from the root to different parts of shoots.

Ans:  True

  1. Walls of sieve tubes are perforated.

Ans:  True

  1. A single large vacuole is present in the cells of sclerenchyma tissues.

Ans:  False, Vacoules are either absent or small in the cells of sclerenchyma tissue

  1. The upper layer in a plant tissue is epidermis.

Ans:  True

  1. Stomata are surrounded by mast cells.

Ans:  False, Stomata are surrounded by guard cells.

  1. Transpiration occurs through stomata.

Ans:  True

 

(C)     Multiple choice questions:

  1. Which of the following tissues is composed of mainly dead cells?

(a) Phloem                    (b) Epidermis

(c) Xylem                       (d) Endodermis

Ans:  (c)

  1. Lignin is a component of the secondary cell walls of

(a) epidermis                (b) collenchyma

(c) sclerenchyma          (d) parenchyma.

Ans:  (c)

  1. Most of the metabolism of a plant is carried out by

(a) parenchyma            (b) collenchyma

(c) sclerenchyma          (d) all of the above

Ans:  (a)

  1. The most common type of ground tissue is

(a) epidermis                (b) collenchyma

(c) sclerenchyma          (d) parenchyma.

Ans:  (d)

  1. Thickenings of collenchyma are due to

(a) lignin                        (b) pectin

(c) cellulose                   (d) suberin.

Ans:  (c)

  1. A mature sieve tube is different from a vessel in

(a) lacking a functional nucleus    

(b) absence of lignin in walls

(c) being dead

(d) lacking cytoplasm.

Ans:  (a)

  1. Simple tissues are

(a) parenchyma, xylem and collenchyma

(b) parenchyma, collenchyma and sclerenchyma

(c) parenchyma,xylem and sclerenchyma

(d) parenchyma, xylem and phloem.

Ans:  (b)

  1. Which of the following is not true about ‘sclereids’?

(a) These are also called stone cells

(b) These form sclerenchyma fibres

(c) These are groups of non living cells

(d) These are found in nut shells, guava pulp, pear.

Ans:  (b)

  1. Aerenchyma is a kind of:

(a) parenchyma            (b) collenchyma

(c) sclerenchyma          (d) xylem

Ans:  (a)

  1. chlorenchyma is formed by

(a) parenchyma            (b) collenchyma

(c) sclerenchyma          (d) xylem

Ans:  (a)

  1. Generally, plant cell wall is made up of:

(a) cellulose and pectin

(b) only cellulose

(c) chitin

(d) murein

Ans:  (b)

  1. Lignified cell wall is the characteristic feature of

(a) phloem cells            (b) epidermal cells

(c) cambial cells           (d) xylem cells.

Ans:  (d)

  1. The strength and rigidity of a cell wall is due to the substance known as

(a) suberin                    (b) cellulose

(c) lignin                        (d) pectin.

Ans:  (b)

  1. The phloem in the plants does the function of

(a) Providing support

(b) Mineral movement

(c) Conduction of food

(d) Conduction of water

Ans:  (c)

  1. Lignified elongated dead cells are

(a) parenchyma            (b) collenchyma

(c) sclerenchyma          (d) none above

Ans:  (c)

  1. Sieve tube cell is

(a) multinucleated       (b) dead cell

(c) nucleated                (d) enucleated

Ans:  (d)

  1. Parenchyma has

(a) intercellular spaces and uniform thickening

(b) deposition on corners

(c) deposition on angles

(d) deposition in form of bands

Ans:  (a)

  1. Chloroplast containing cell is

(a) collenchyma           (c) sclerenchyma

(c) Aerenchyma            (d) chlorenchyma

Ans:  (d)

  1. Husk of coconut is made up of

(a) Sclerenchyma         (b) Collenchyma

(c) Parenchyma            (d) None

Ans:  (a)

  1. Which of the following contains dead cells?

(a) Meristematic tissue

(b) Xylem

(c) Parenchyma

(d) Collenchyma

Ans:  (b)

  1. Which is not a function of epidermis

(a) Protection from adverse condition  

(b) Gaseous exchange

(c) Conduction of water

(d) Transpiration

Ans:  (c)

  1. Flexibility in plants is due to

(a) Collenchyma           (b) Sclerenchyma

(c) Parenchyma            (d) Chlorenchyma

Ans:  (a)

 

(D)    Identify the following type of tissue:

  1. Cell wall unevenly thickened with cellulose corners.

Ans:  Collenchyma

  1. Occurs below epidermis in stems.

Ans:  Collenchyma

  1. It has thin, cellulose cell wall.

Ans:  Parenchyma

  1. Tissue that conducts food.

Ans:  phloem

  1. Conducts water and minerals from the root to the leaves.

Ans:  Xylem

  1. A tissue that provides buoyancy in aquatic plants.

Ans:  aerenchyma

  1. Parenchyma that helps in photosynthesis.

Ans:  chlorenchyma

  1. Tissue that forms hard shell of coconut.

Ans:  sclerenchyma

  1. Part of xylem tissue that provides mechanical strength to plants.

Ans:  xylem fibers

  1. The only dead part of phloem complex tissue.

Ans:  phloem fibers

  1. Waterproof layer present on the outer wall of epidermal cells.

Ans:  Cuticle

  1. Tissues concerned with the transportation of food, water and minerals.

Ans:  Vascular

  1. Name main conducting element of phloem.

Ans:  Sieve tube

  1. Name the element of xylem which is elongated with tapering end.

Ans:  Tracheids

  1. The perforated end walls of sieve tube?

Ans:  Sieve plate

  1. Which living cell of phloem does not contain nucleus at maturity?

Ans:  Sieve tube

 

Animal Tissues

  • The animal tissues are classified as
    1. Epithelial tissue
    2. Muscle or muscular tissue
    3. Connective tissue and
    4. Nervous tissue

S.No.

Tissue

Function

1

Epithelial tissue

Protection

2

Muscular tissue

Movement

 

3

Connective tissue

Support

4

Nervous tissue

Transmission

 

 

 

Epithelial Tissue (Epithelium):

Nature:

  • Epithelial tissue is the simplest tissue. It is the protective tissue of the animal body. The cells of this tissue are tightly packed and it forms a continuous sheet.
  • It covers most organs and cavities within the body.
  • It also forms a barrier to keep different body systems separate.
  • The skin and lining of buccal cavity blood vessels, alveoli (or lungs) and kidney tubules are made of epithelial tissue.
  • Epithelial tissue may be simple, i.e., composed of a single layer of cells, or stratified. i.e., made up of several layers of cells.

 

Types of epithelial tissue:

  1. Squamous epithelium;
  2. Cuboidal epithelium;
  3. Columnar epithelium;
  4. Glandular epithelium;
  5. Ciliated epithelium

 

 

Squamous Epithelium:

Nature:

  • It is made up of thin, flat, irregular-shaped cells which fit together like floor tiles to form a compact tissue.

Occurrence:

  • It forms the delicate lining of cavities nose, blood vessels.

Function:

  1. It protects the underlying parts of body from mechanical injury.
  2. It also forms a selectively permeable surface through which filtration occurs.

Cuboidal Epithelium:

Nature:

  • It consists of cube-like cells which are square in section.

Occurrence:

  • It is found in kidney tubules, thyroid vesicles and in glands (e.g., salivary glands, sweat glands.

Functions:

  • It helps in absorption, excretion and secretion. It also provides mechanical support.

 

Columnar Epithelium:

Nature:

  • It consists of cells which are taller than broad (i.e., pillar-like). The nuclei are towards the base.

Occurrence:

  •  It forms lining of stomach, small intestine and colon.

Function:

  • Main functions include absorption and secretion.

Glandular Epithelium:

  • The columnar epithelium is often modified to form glands which secrete chemicals.

Ciliated Epithelium:

Nature:

  • Certain Cuboidal or columnar cells have a free border which bears thread-like cytoplasmic outgrowths, called cilia.

Occurrence:

  • The ciliated columnar epithelium lines the trachea, bronchi kidney tubules and oviducts.

 

Function:

  • The rhythmic, concerted beating of the cilia moves solid particles in one direction through the ducts.

 

 

 

Muscle Tissues (or Muscular Tissues)

  • Muscle cells are elongated and large-sized, so they are also called muscle fibres. On the basis of their location, structure and function, there are following three types of muscle fibres: striated (Skeletal), unstriated (smooth) and cardiac muscles.

 

Striated Muscles:

Nature:

  • These muscles are also known as striped, skeletal or voluntary muscles.
  • Entire muscle fibres show alternate dark and light stripes, they are called striped muscles are responsible for body movements, they are called skeletal muscles.
  • These muscles work according to our will also called voluntary muscles.
  • The striated muscle fibres (cells) are long or elongated, cylindrical and unbranched.
  • Its nuclei are peripheral in position.

 

Occurrence:

  • Striated muscles occur in muscles of limbs body wall, face, neck, etc.

Functions:

  • Striated muscles are powerful and undergo rapid contraction. These muscles can be tired and need rest.
  •  Striated muscles provide the force for locomotion and all other voluntary movements of the body.

Smooth Muscles:

Nature

  • These are also known as unstriated, visceral or involuntary muscles.
  • Smooth muscles occur as bundles or sheets of elongated fusiform or spindle-shaped (pointed at both ends) cells or fibres.
  • These are held together by loose connective tissue. They possess a single centrally located nucleus.

Occurrence:

  • Smooth muscles are found in the walls of the hollow (tubular) visceral organs in the wall of alimentary canal internal organs, ducts of glands, urinogenital ducts and blood vessels.

Functions:

  • Smooth muscles do not work according to our will.

 

Cardiac Muscles:

Nature

  • Cardiac muscles show characteristics of both smooth and striated muscles.
  • Cardiac muscles are composed of branched fibres, the branches join to form a network.
  •  Cardiac muscles have stripes or light and dark bands. These muscle fibres show densely strained cross–bands intercalated discs.
  • They possess numerous mitochondria thus fulfill their high need of energy.

Occurrence:

  • The cardiac muscles occur in the heart.

Functions:

  • Cardiac muscles contract and relax rapidly, rhythmic contraction and relaxation of the heart muscles help to pump and distribute blood to various parts of body.

 

Questions

(A)    Fill in the blanks:

  1. Tissues together form an ________.

Ans:  Organ

  1. Lining of blood vessels is made up of _______ epithelial tissue.

Ans:  squamous

  1. Epithelial cells with cilia are found in _________of our body.

Ans:  Respiratory tract

  1. Squamous epithelium is also known as ________.

Ans:  pavement epithelium

  1. The main function of squamous epithelial tissue is to provide________ to underlying organs from mechanical injury.

Ans:  protection

  1. The outer thin membrane of muscle cell is known as _______.

Ans:  sarcolemma

  1. _________ is the simplest kind of animal tissue.

Ans:  epithelial

  1. __________epithelium consists of cube-like cells.

Ans:  Cuboidal

  1. ________epithelium consists of tall or pillar like cells.

Ans:  Columnar

  1. The columnar epithelium is often modified to form _______ which secrete chemicals.

Ans:  glands

  1. Striated muscles are also known as ___________ muscles.

Ans:  skeletal

  1. If cuboidal or columnar cells of epithelial tissue bear cilia on their free surface than it is known as ___________ epithelial tissue.

Ans:  ciliated

  1. The rhythmic beating of___________ helps in moving solid particles in one direction through the ducts.

Ans:  cilia

  1. _________ epithelium consists of columnar cells modified to secrete chemicals.

Ans:  Glandular

  1. _________muscles do not work according to our will.

Ans:  involuntary

  1. Muscles that work according to our own will is known as ___________ muscles.

Ans:  voluntary

  1. _______ muscles are confined to heart walls, pulmonary veins and superior vena cava.

Ans:  cardiac

  1. _______ muscles are found in the walls of the hollow (tubular) visceral organs.

Ans:  Smooth

  1. Cardiac muscles show characteristics of both ______ and ______ muscles.

Ans:  smooth, striated

  1. Muscle tissue generally helps in _______ of the body.

Ans:  movement

 

 

(B)    State whether the following statement is true or false. If false then state the correct statement:

  1. Cuboidal epithelium is found in the inner lining of cheek.

Ans:  True

  1. Skeletal muscles are called involuntary muscles and smooth muscles are called voluntary muscles.

Ans:  False, Skeletal muscles are voluntary muscles and smooth muscles are called involuntary muscles.

  1. Epithelial tissues are also commonly termed as ‘packaging tissue ‘ in animals.

Ans: False, Epithelial tissues are also commonly termed as ‘pavement tissue ‘ in animals.

  1. Epithelial tissue is protective tissue in animal body.

Ans:  True

 

  1. The lining of blood vessels, long alveoli and kidney tubules are all made up of epithelial tissue.

Ans:  True

  1. Epithelial cells have a lot of permeable layer.

Ans:  True

  1. Epithelial layer does not allow regulation of materials between body and external environment.

Ans: False, Epithelial layer allow regulation of materials between body and external environment.

  1. Cardiac muscles possess numerous mitochondria thus fulfill their high need of energy.

Ans:  true

  1. The striated muscle cells branched, while cardiac muscle cells are unbranched.

Ans:  false, striated muscle cells unbranched, while cardiac muscle cells are branched

  1. Intercalated disc are present in smooth muscles.

Ans:  false, Intercalated disc are present in cardiac muscles

 

(C)     Multiple choice Questions:

  1. Large intercellular spaces are present in

(a) Epithelial tissue

(b) Connective tissue

(c) Muscular tissue

(d) Nervous tissue

Ans:  (b)

  1. Choose the wrong statement from the following

(a) The nature of matrix differs according to the function of the tissue.

(b) Epithelial tissue have intercellular spaces between them.

(c) Fats are stored below the skin and in between the internal organs.

(d) Cells of striated muscles are multinucleate and unbranched.

Ans:  (b)

  1. Muscles contain special proteins called

(a) Tubulins

(b) Contractile proteins

(c) Carrier proteins

(d) Globulins

Ans:  (b)

  1. Intercalated disc is present in

(a) Cardiac muscles

(b) Straited muscles

(c) Smooth muscles

(d) Both (a) & (b)

Ans:  (a)

  1. Intestine absorbs the digested food materials. What type of epithelial cells is responsible for that?

(a) Stratified squamous epithelium

(b) Columnar epithelium

(c) Spindle fibres

(d) Cuboidal epithelium

Ans:  (b)

  1. While doing work and running, you move your organs like hands, legs etc. Which among the following is correct?

(a) Smooth muscles contract and pull the ligament to move the bones

(b) Smooth muscles contract and pull the tendons to move the bones

(c) Skeletal muscles contract and pull the ligaments to move the bones

(d) Skeletal muscles contract and pull the tendons to move the bones

Ans:  (c)

  1. Which muscle act involuntarily?

(i) Striated muscles

(ii) Smooth muscles

(iii) Cardiac muscles

(iv) Skeletal muscles

(a) (i) & (ii)                    (b) (ii) & (iii)

(c) (iii) & (iv)                  (d) (i) & (iv)

Ans:  (b)

  1. Contractile proteins are found in

(a) Bones                       (b) Blood

(c) Muscles                   (d) Cartilage

Ans:  (c)

  1. Voluntary muscles are found in

(a) Alimentary canal

(b) Limbs

(c) Iris of the eye

(d) Bronchi of lungs

Ans:  (b)

  1. The muscular tissue which function throughout the life continuously without fatigue

(a) Skeletal muscle

(b) Cardiac muscle

(c) Smooth muscle

(d) Voluntary muscle

Ans:  (b)

  1. The muscular tissue of urinary bladder has

(a) Striated          (b) Unstriated               (c) Ligament                 (d) Tendon

Ans:  (b)

  1. Striated muscles are

(a) Multinucleate and unbranched

(b) Uninucleate and spindle-shaped

(c) Uninucleate and branched

(d) Multinucleate and branched

Ans:  (a)

 

(D)    Identify the following:

  1. One of simplest animal tissue forming protective layer.

Ans:  Epithelial

  1. Tissue with protoplasmic projections on cells.

Ans:  Ciliated epithelium

  1. Tissue with cells in forms of fibres.

Ans:  Muscle

  1. Specialized heart muscles.

Ans:  Cardiac

  1. Muscles that attaches to bones and helps in movement of body.

Ans:  smooth muscles

  1. Zig-zag thickenings in cardiac muscles.

Ans:  Intercalated disc

  1. Tissue that forms inner lining of our mouth.

Ans:  Stratified epithelium

Connective Tissue

  • The cells of connective tissue are living, separated from each other (i.e., loosely spaced) and are very less in number.
  •  Homogeneous, gel-like intercellular substance called medium or matrix forms the main bulk of the connective tissue.
  • The main functions of connective tissue are binding, supporting, and packing together different organs of the body.


Loose regular Connective Tissue:

(a)     Areolar tissue:

Nature:

  • It is a loose and cellular connective tissue. Its matrix consists of two kinds of fibres.
    1. White collagen fibres.
    2. Yellow elastic fibres or elastin.

Occurrence:

  • It is found around muscles, blood vessels and nerves.

Functions:

  1. It acts as a supporting and packing tissue between organs lying in the body cavity.
  2. It helps in repair of tissues after an injury.
  3. It also helps in combating foreign toxins.
  4. It fixes skin to underlying muscles.

(b)     Adipose Tissue:

Nature:

  • Adipose tissue is basically an aggregation of fat cells or adipocytes. Each fat cell is round or oval and contains a large droplet of fat that almost fills it.

Occurrence:

  • The adipose tissue is abundant below the skin, between the internal organs.

Functions:

  1. It serves as a fat reservoir.
  2. It keeps visceral organs in position. It forms shock-absorbing cushions around kidneys and eye balls.
  3. It act as an insulator

Dense Regular Connective Tissue:

  • It is a fibrous connective tissue. Dense regular connective tissue is the principal component of tendons and ligaments.
    1. Tendons:
  • Tendons join skeletal muscles to bones. It has great strength but its flexibility is limited.

 

 

  1. Ligaments:
  • They are elastic structures which connect bones to bones. A ligament is highly elastic bones.

 

Skeletal Tissue:

  • The skeletal tissue or supporting tissue includes cartilage and bone

 

  1. Cartilage:

Nature:

  • The cartilage is a specialized connective tissue.
  • Matrix is composed of proteins and calcium salts.
  • Its matrix is produced and maintained by the chondrocytes.

       

Occurrence:

  • Cartilage is located in the ear pinna, nose tip, epiglottis, ring of trachea.

Functions:

  • It provides support and flexibility to the body parts. It smoothens surface at joints.

 

  1. Bone:

Nature:

  • Bone is a very strong and non-flexible tissue.
  • Its matrix is very hard and rigid which is made up of proteins like osteonectin, osteocalcin and salts of calcium and magnesium generally carbonates and phosphates.
  • These minerals provide hardness to the bone and they are arranged in the form of concentric rings called lamellae.
  • Bone cells, called osteoblasts or osteocytes are present between the lamellae in fluid-filled spaces called lacunae.
  • All lacunae communicate with each other by network of fine canals, called canaliculi.

                            

Functions:

  1. It provides shape to the body.
  2. It provides skeletal support to body.
  3. It protects vital body organs such as brain, lungs, etc.
  4. It serves as storage site of calcium and phosphate.
  5. It anchors the muscles.

Fluid Connective Tissue:

  • Fluid connective links the different parts of body. It includes blood and lymph.
  1. Blood:
  • Blood is a fluid connective tissue. In this tissue cells move in a fluid or liquid matrix blood plasma. Plasma contains cells called blood corpuscles or cells. These blood corpuscles are:
    1. Red blood corpuscles, (RBCs) or erythrocytes;
    2. White blood cells, (WBCs) or leucocytes;
    3. Platelets

 

Occurrence:

  • Blood occurs in blood vessels called arteries, veins and capillaries which are connected together to form the circulatory system.

 

Functions:

  1. Blood transports nutrients, hormones and vitamins to the tissues and transports excretory products from the tissues to the liver and kidney.
  2. The red blood corpuscles (RBCs) carry oxygen to the tissues for the oxidation of food stuff.
  3. The white blood cells (WBCs) fight disease either by engulfing and destroying foreign bodies or by producing antitoxins and antibodies that neutralise the harmful effects of germs.
  4. Blood platelets disintegrate at the site of injury and help in the clothing of blood.

 

  1. Lymph:

Nature:

  • Lymph is a colourless fluid that has filtered out of the blood capillaries. It is part of blood, its composition is similar to that of blood except that red blood corpuscles and some blood proteins are absent in it.

Functions:

  1. Lymph transports the nutrients (oxygen, glucose) that may have filtered out of the blood capillaries back into the heart to the re-circulated in the body.

(ii)     Being loaded with WBCs such as lymphocytes, the lymph protects the body against infection.

 

Nervous Tissues

Nature:

  • A tissue which is specialized to transmit message in our body is nervous tissue. Brain, spinal, cord and nerves are all composed of nervous tissue. Nervous tissue cells called nerve cells or neurons. Neurons have the ability to receive stimuli outside the body and conduct to different parts of the body. The impulse travels from one neuron to another neuron.

 

Neuron has three parts:

  1. The cyton or cell body which contains a central nucleus and cytoplasm with characteristic deeply stained Nissl’s granules.
  2. The dendrons which are short process arising from the cyton and further branching into dendrites.
  3. The axon which is a single, long cylindrical process of uniform diameter.

Functions:

  • The dendrites receive impulses and the axon takes impulses away from the cell body.

 

Questions

(A)    Fill in the blanks:

  1. ___________tissue forms protective sheath and packing material around various organs.

Ans: connective

  1.  ________ tissue is the most widely distributed connective tissue in animals.

Ans:  Areolar

  1. _________ fibres provide flexibility and strength whereas ________ fibres provide elasticity.

Ans:  Collagen, elastic

  1. Dense regular connective tissue is the principal component of ________ and _________.

Ans: tendon, ligament

  1. The _________connects skeletal muscles with the bones.

Ans:  tendon

  1. The ___________serve to bind bones together.

Ans:  ligament

  1. ___________is primarily a fat storing tissue.

Ans:  adipose

  1. ________tissue serves as an insulator to prevent the loss of heat from body.

Ans:  Adipose

  1. __________is a hard but flexible skeletal tissue consisting of living cells embedded in a matrix.

Ans: Cartilage

  1. __________ is very strong and non-flexible vertebrate connective tissue.

Ans:  Bone

  1. A compact bone consists of living bone cells, called _________.

Ans:  Osteoblasts

  1. Hardness of bone is due to _______ and ________ compounds present in bones.

Ans:  calcium, phosphorous

  1. Fluid tissue is also known as____________.

Ans:  vascular tissue

  1. ________ is the most important fluid connective tissue.

Ans:  blood

  1. __________ and _________ are important components of blood.

Ans:  Plasma, cells

  1. __________ and _________ are the types of fluid connective tissue.

Ans:  blood, lymph

  1. _________ tissue is present in brain, spinal cord and sense organs.

Ans:  Nervous

  1. The main cell body of a neuron is also called as ________.

Ans:  cyton

  1. The short much-branched and tapering projections arising from the nerve cell body are _________.

Ans:  dendrites

  1. The __________ is long cylindrical process arising from the main cell body of neuron.

Ans:  axon

 

(B)    State whether the following statement is true or false. If false then state the correct statement:

  1. Blood vessels are present in cartilage tissue.

Ans:  False, Blood vessels are absent in cartilage tissue.

  1. The areolar connective tissue joins skin to muscles and supports internal organs.

Ans:  True

  1. Leucocytes help in clotting blood.

Ans:  False, Thrombocytes help in blood clotting.

  1. Blood and lymph are fluid connective tissues found in animals.

Ans:  True

  1. Both ligaments and tendons belong to dense regular connective tissue which consists of ordered and densely packed fibres and cells.

Ans:  True

  1. Neurons are the structural and functional units of nervous tissue.

Ans:  True

  1. Hump of camel and blubber of whale has rich adipose tissue for storing fats.

Ans:  True

  1. Nervous tissue are found in nerves only.

Ans:  False, Nervous tissue are found in nerves, brain and spinal cord.

 

(C)     Multiple Choice Questions:

  1. Bone and cartilage belong to which tissue?

(a) Nervous tissue

(b) Epithelial tissue

(c) Muscular tissue

(d) Connective tissue

Ans:  (d)

  1. Areolar connective tissue is found

(a) Around blood vessels and nerves

(b) Between skin and muscles

 (c) In the bone marrow

(d) All of the above

Ans:   (d)

  1. A person met with an accident in which two long bones of hand were dislocated. Which among the following may be possible?

(a) Tendon break

(b) Break of skeletal tissue

(c) Ligament break

(d) Areolar tissue break

Ans:  (c)

  1. Select the incorrect sentence

(a) Blood has matrix containing proteins, salts and hormones

(b) Two bones are connected with ligament

(c) Tendons are non-fibrous tissue and fragile

(d) Cartilage is a form of connective tissue

Ans:  (c)

  1. Cartilage is not found in

(a) Nose                        (b) Ear

(c) Kidney                      (d) Larynx

Ans:  (c)

  1. Fats are stored in human body as

(a) Cuboidal epithelium

(b) Adipose tissue

(c) Bones

(d) Cartilage

Ans:  (b)

  1. Bone matrix is rich in

(a) Fluoride and calcium

(b) Calcium and phosphorus

(c) Calcium and potassium

(d) Phosphurus and potassium

Ans:  (b)

  1. Nervous tissue is not found in

(a) Brain                        (b) Spinal Cord

(c) Tendons                   (d) Nerves

Ans:  (c)

  1. Nerve cells do not contain

(a) Axon                         (b) Nerve endings

(c) Tendons                   (d) Dendrites

Ans:  (c)

  1. Which of the following helps in repair of tissue and fills up the space inside the organ?

(a) Tendon                     (b) Adipose tissue

(c) Areolar                     (d) cartilage

Ans:  (c)

  1. Choose the wrong statement

(a) Epithelial tissues have intercellular spaces between them

(b) Fats are stored below the skin and in between the internal organs

(c) The nature of matrix differs according to the function of the tissue

(d) Cells of striated muscles are multinucleate and unbranched

Ans:  (a)

  1. Dendrites are found in

(a) Striated muscle

(b) Cardiac muscle

(c) unstriated muscle

(d) Neuron

Ans:  (d)

  1. The cell body of a nerve cell contains a nucleus and cytoplasm and is called the

(a) Cyton                        (b) Axon

(c) Dendron                  (d) None

Ans: (a)

  1. Spinal cord and brain are made up of

(a) Muscular tissue      (b) Vascular tissue

(c) Nervous tissue        (d) Skeletal tissue

Ans:  (c)

  1. Which one of the following is not a function of a bone?

(a) Bones provide a frame to keep the body supported.

(b) By virtue of the smooth surface, bones provide a sliding area which reduces friction and facilitates movement.

(c) Bones act as reserves of minerals

(d) Bones produce blood cells.

Ans:  (b)

 

(D)    Identify the following Tissue:

  1. Fundamental type of connective tissue.

Ans:  Areolar

  1. Tissue that connect muscles to bones.

Ans:  Tendon

  1. Connective tissue present between two bones.

Ans:  Ligaments

  1. Hard tissue found in external ear.

Ans:  Cartilage

  1. Hard porous non-flexible skeletal tissue.

Ans:  Bone

  1. Structural & functional unit of nervous system.

Ans:  Neurons

  1. Long extension from cyton.

Ans:  Axon

  1. A fluid similar to blood which has WBCs but no RBCs.

Ans:  Lymph

  1. Tissue filled with fat.

Ans:  Adipose

  1. Cells embedded in loose matrix of cartilage.

Ans:  chondrocytes