Tissues Notes

Tissues, class 9 Notes

A tissue is a group of similar cells that work together to perform a specific function. The cells in a tissue have a common origin, similar structure, and are organized to carry out particular tasks in the body. Our tissues play an important role in the division of labor because different tissues perform different functions. This specialization increases efficiency. Tissues provide support and framework to the body and organs. Since similar type of cells work together, the functioning becomes faster and more organized.

Classification of tissues

Tissues are majorly classified as plant tissues and animal tissues. The table below illustrates the detailed classification of tissues.

Tissue Type		Sub-types	Characteristics	Function
Plant Tissues
Meristematic Tissue	· Apical · Lateral · Intercalary		Cells are small, undifferentiated, and capable of division.	Responsible for growth (increase in length, girth, and formation of new organs).
Permanent Tissue	· Simple · Complex		Cells are differentiated and cannot divide.	Perform specific functions like photosynthesis, storage, and transport.
Simple Tissue	· Parenchyma · Collenchyma · Sclerenchyma		Consists of one type of cell.	Parenchyma: Photosynthesis, storage; Collenchyma: Support; Sclerenchyma: Strength and support.
Complex Tissue	· Xylem · Phloem		Made up of more than one type of cell.	Xylem: Transports water and minerals; Phloem: Transports food and nutrients.
Animal Tissues
Epithelial Tissue	· Squamous epithelium · Cuboidal epithelium · Columnar epithelium · Ciliated epithelium		Cells are closely packed with little intercellular space.	Protection, secretion, absorption, and filtration.
Connective Tissue	· Loose connective tissues · Dense connective tissues · Cartilage · Bone tissue · Blood tissue		Cells are scattered in an extracellular matrix.	Support, binding, and transport of nutrients.
Muscle Tissue	· Skeletal muscles · Smooth muscles · Cardiac muscles		Cells are elongated and contractile.	Movement and locomotion (skeletal), involuntary movement (smooth), contraction of the heart (cardiac).
Nervous Tissue	· Neurons · Neuroglia		Cells are specialized for receiving and transmitting signals.	Control and coordination of body functions through electrical impulses.

PLANT TISSUES

Meristematic Tissue (Growth Tissue)

Meristematic tissues are a group of actively dividing (mitotically active) cells in plants. These tissues are responsible for the growth of the plant in length, thickness, and the formation of new organs like leaves, flowers, and branches.

Characteristics of Meristematic Tissue:

Feature	Description
Cell Shape	Small, cube-shaped, or rectangular cells
Cell Wall	Thin cell walls made of cellulose
Vacuoles	Absent or very small (as cells are actively dividing)
Cytoplasm	Dense and abundant
Nucleus	Large and prominent
Intercellular Spaces	Absent (cells are tightly packed)
Function	Responsible for plant growth by continuous cell division

Location and Types of Meristematic Tissues:

Meristematic tissues are classified based on their location in the plant:

1. Apical Meristem

Location: Found at the tips of roots and shoots.
Function: Causes primary growth (increase in length).
Example: Root tips growing deeper into the soil, shoot tips growing upward.

2. Intercalary Meristem

Location: Found at internodes or base of leaves, especially in grasses.
Function: Helps in the regrowth of parts (like after grazing or cutting).
Example: Regrowth in grasses and sugarcane.

3. Lateral Meristem

Location: Found along the sides of stems and roots (in vascular bundles).
Function: Causes secondary growth (increase in girth/thickness).
Examples:
- Vascular cambium – produces secondary xylem and phloem.
- Cork cambium – forms protective bark.

Functions of Meristematic Tissue:

Function	Details
Growth	Responsible for both primary (length) and secondary (thickness) growth.
Formation of New Organs	Generates new leaves, buds, flowers, and branches.
Healing and Regeneration	Helps in the repair of injured parts.
Cell Differentiation Source	Gives rise to permanent tissues through the process of differentiation.

Type	Location	Function	Example
Apical	Root and shoot tips	Increases plant length	Root/shoot elongation
Intercalary	Base of leaves/internodes	Growth in regions like grasses	Grass regrowth
Lateral	Sides of stem/roots	Increases thickness (girth)	Formation of bark, wood

Permanent Tissue

Permanent tissues are mature, specialized plant tissues formed from meristematic tissues. These cells lose their ability to divide and become differentiated to perform specific functions such as support, transport, storage, and protection.

Characteristics of Permanent Tissue:

Feature	Details
Cell Division	Cells do not divide (non-meristematic)
Cell Structure	Cells are differentiated with specific shapes and sizes
Vacuoles	Present and often large
Intercellular Spaces	May be present (varies with tissue type)
Function	Support, storage, transport, photosynthesis, protection
Origin	Derived from meristematic tissue after maturation

Types of Permanent Tissue

Permanent tissues are classified into two main types:

Type	Subtypes	Based on
1. Simple Permanent	Parenchyma, Collenchyma, Sclerenchyma	One type of cell
2. Complex Permanent	Xylem, Phloem	More than one type of cell

1. Simple Permanent Tissue

Made of only one type of cell, performing similar functions.

a. Parenchyma

Structure:
- Living, thin-walled, unspecialized cells.
- Large intercellular spaces.
Function:
- Storage of food and water.
- Photosynthesis (when containing chloroplasts – called chlorenchyma).
- Buoyancy in aquatic plants (when air-filled – called aerenchyma).
Location: Soft parts like pith, cortex, mesophyll of leaves.

b. Collenchyma

Structure:
- Living cells with thickened corners (cellulose/pectin).
- Elongated cells, no large intercellular spaces.
Function:
- Provides flexible support to growing parts.
- Allows bending without breaking.
Location: Leaf stalks, below epidermis of stems.

c. Sclerenchyma

Structure:
- Dead cells with very thick, lignified walls.
- No intercellular space; narrow lumen.
Function:
- Provides rigidity and strength.
- Protects the plant body.
Location: Husk of seeds, shells of nuts, fibers.

2. Complex Permanent Tissue

Made of more than one type of cell, working together for a common function — mainly transport.

a. Xylem (Water-Conducting Tissue)

Function: Transports water and minerals from roots to the rest of the plant.
Components:
- Tracheids: Long, dead cells with tapered ends.
- Vessels: Tubular, wide, dead cells forming continuous water channels.
- Xylem parenchyma: Living cells for food storage.
- Xylem fibres: Dead, for support.
Direction of flow:Unidirectional (roots to leaves)

b. Phloem (Food-Conducting Tissue)

Function: Transports food (sugars) from leaves to all parts of the plant.
Components:
- Sieve tubes: Living, tube-like, with sieve plates.
- Companion cells: Nucleated cells that help sieve tubes.
- Phloem parenchyma: Living cells for storage.
- Phloem fibres: Only dead part of phloem, provides support.
Direction of flow:Bidirectional (up and down)

Summary Table of Permanent Tissues

Type	Subtype	Cell Type	Function	Special Feature
Simple	Parenchyma	Living	Storage, photosynthesis	May become chlorenchyma or aerenchyma
Collenchyma	Living	Flexible support	Thickened cell corners
Sclerenchyma	Dead	Rigidity and strength	Thick, lignified walls
Complex	Xylem	Mostly dead	Water transport	Vessels and tracheids help conduction
Phloem	Mostly living	Food transport	Sieve tubes and companion cells work together

Difference Between Simple and Complex Permanent Tissue

Feature	Simple Permanent Tissue	Complex Permanent Tissue
Cell type	One type of cell	Multiple types of cells
Function	Support, storage, photosynthesis	Transport of water and food
Examples	Parenchyma, Collenchyma, Sclerenchyma	Xylem and Phloem

Protective Tissue in Plants

Protective tissues are specialized permanent tissues in plants that form the outer covering of plant organs. Their primary function is to protect the plant from mechanical injury, water loss, infection, and extreme environmental conditions.

Features of Protective Tissue:

Feature	Details
Cell Division	Cells are mature and non-dividing
Cell Structure	Cells are closely packed with thick cell walls
Function	Protection from injuries, pathogens, dehydration, and temperature
Composition	Mostly dead or highly thickened cells
Intercellular Spaces	Absent or very minimal

Types of Protective Tissue in Plants include epidermis and cork(phellem)

1. Epidermis

Found in the outer layer of leaves, stems, roots, flowers, and fruits. It is made of single-layered, flat, and tightly packed cells. Usually without chloroplasts (except in guard cells). They are covered with a waxy coating called cuticle (especially in aerial parts) with no intercellular spaces. They may contain stomata (in leaves) for gas exchange.

Functions of epidermis

Function	Explanation
Protection	Prevents mechanical injury and invasion by microorganisms.
Water conservation	Cuticle prevents excessive water loss through evaporation.
Gas exchange	Stomata regulate the entry and exit of gases like CO2 and O2.
Absorption (roots)	Root hairs (extensions of epidermal cells) help absorb water and minerals.

Specialized epidermal cells are Guard cells and root hair. Guard cells are kidney-shaped cells that regulate opening and closing of stomata while the root hair absorb water and minerals from the soil.

2?. Cork (Phellem)

Found in older stems and roots, forming the outermost protective layer (bark).It is made of dead cells. Walls are thickened with a waxy substance called suberin, which is impermeable to water and gases. There is no intercellular space.

Function	Explanation
Prevents water loss	Suberin blocks water evaporation.
Protects internal tissues	From injury, heat, cold, and microbial attacks.
Replaces epidermis	In mature stems when the plant increases in girth due to secondary growth.

Difference Between Epidermis and Cork

Feature	Epidermis	Cork (Phellem)
Cell type	Living cells	Dead cells
Location	Outer layer of young plant parts	Outer layer of mature stems/roots
Permeability	Semi-permeable (has stomata)	Impermeable (suberized walls)
Function	Protection and gas exchange	Protection and prevention of water loss

Difference Between Meristematic and Permanent Tissue:

Feature	Meristematic Tissue	Permanent Tissue
Cell Division	Actively divides	Cells do not divide
Vacuoles	Absent or small in size	Large ,and well developed vacuoles
Function	Help in the growth	They support, storage, transport, etc.
Cell Wall	Thin and uniform	May be thickened or lignified
Location	Found in the root tip, shoot tip, and nodes	Found throughout the plant

Animal Tissues

The animal cells are grouped together to form animal tissues. These tissues vary in their structure, function, and origin. Animal tissues are classified into four basic types: epithelial, connective, muscular, and nervous tissues.

Epithelial Tissues

Epithelial tissues form the protective covering and inner lining of the body and organs. These were the first tissues to evolve during evolution and are formed during embryonic development. They originate from all three germ layers — ectoderm, mesoderm, and endoderm.

Characteristics of Epithelial Tissues

Important features of epithelial tissues include:

They can be single-layered (simple) or multi-layered (stratified).
They have high regenerative capacity.
Cells are tightly packed and joined by special junctions like tight junctions, gap junctions, desmosomes, and adherens junctions.
Their plasma membrane may have specializations such as cilia, flagella, and microvilli.

Classification of Epithelial Tissues

Type	Structure	Location	Function
Simple Squamous Epithelium	- Single thin layer of flat, disc-like cells - Centrally placed flat nucleus - Rest on a basement membrane	- Air sacs (alveoli) of lungs - Lining of heart and blood vessels (endothelium) - Bowman's capsule in kidneys - Lining of body cavities (mesothelium)	- Facilitates diffusion of gases and nutrients - Allows filtration in kidneys - Provides smooth lining to reduce friction
Simple Cuboidal Epithelium	- Single layer of cube-shaped cells - Centrally placed round nucleus - May contain microvilli for absorption	- Kidney tubules - Ducts of salivary and thyroid glands - Ovary surface - Pancreatic ducts	- Absorption and secretion - Supports glandular secretion - Maintains structural integrity of ducts
Simple Columnar Epithelium	- Single layer of tall, rectangular cells - Nucleus at the base - May have goblet cells for mucus secretion - Sometimes ciliated or with microvilli	- Lining of stomach, small intestine, and colon - Gallbladder - Uterus and uterine tubes	- Absorption of nutrients - Secretion of digestive enzymes and mucus - Protection and transport (in uterus)
Ciliated Columnar Epithelium	- Columnar cells with fine cilia on the free surface - Nucleus at basal region - May include goblet cells	- Lining of respiratory tract (trachea, bronchi) - Fallopian tubes - Ventricles of the brain	- Cilia beat rhythmically to move particles - Removes mucus and dust from respiratory tract - Propels ova in female reproductive system
Transitional Epithelium (Urothelium)	- Several layers of cells - Surface cells are dome-shaped when relaxed, flattened when stretched - Highly elastic	- Urinary bladder - Ureters - Part of urethra	- Allows expansion and recoil of urinary organs - Prevents leakage during stretching - Acts as a barrier to urine toxins
Glandular Epithelium	- Specialized epithelial cells for secretion - May be unicellular (e.g., goblet cells) or multicellular (e.g., salivary glands) - Classified into exocrine and endocrine glands	- Sweat glands - Salivary glands - Pancreas (both endocrine & exocrine) - Thyroid gland - Goblet cells in intestinal lining	- Secretes enzymes, hormones, sweat, saliva, mucus - Exocrine: via ducts - Endocrine: directly into blood

Connective Tissues

Connective tissue is one of the four primary tissue types in animals (the others are epithelial, muscle, and nervous). It connects, supports, binds, or separates other tissues and organs. These tissues are abundant, widely distributed, and characterized by cells embedded in an extracellular matrix (ECM).

General Features of Connective Tissues

Feature	Description
Origin	Derived from mesoderm (middle embryonic germ layer)
Matrix	Large amount of intercellular matrix (fluid, semi-solid, or solid)
Vascularity	Mostly highly vascular (except cartilage, which is avascular)
Cells Present	Fibroblasts, adipocytes, mast cells, plasma cells, macrophages, and WBCs
Fibers	Collagen (strength), Elastic (flexibility), Reticular (support)

Classification of Connective Tissues

Connective Tissue Proper

Loose Connective Tissue

Structure: Loose arrangement of fibers and cells in semi-fluid ground substance.

Type	Structure	Location	Function
Areolar Tissue	Contains fibroblasts, macrophages, mast cells; loosely packed	Beneath skin, around blood vessels, between organs	Binds organs, holds tissue fluids, supports epithelium
Adipose Tissue	Fat-filled cells (adipocytes), richly vascular	Under skin, around kidneys, heart, eyeballs	Stores energy, insulates body, cushions organs

Dense Connective Tissue

Structure: Densely packed collagen fibers with fewer cells.

Type	Structure	Location	Function
Dense Regular	Fibers arranged in parallel (strong in one direction)	Tendons (muscle to bone), ligaments (bone to bone)	Strength and resistance to tension
Dense Irregular	Irregular fiber arrangement	Dermis of skin, organ capsules	Withstands tension in many directions

Supportive Connective Tissue

Cartilage

Structure: Chondrocytes in lacunae, flexible matrix, avascular, covered by perichondrium

Type	Structure	Location	Function
Hyaline Cartilage	Glossy, bluish-white matrix; few fibers	Nose tip, trachea, ends of long bones, fetal skeleton	Supports, reduces friction, smooth surface
Elastic Cartilage	Visible elastic fibers	External ear, epiglottis	Provides flexibility and shape
Fibrocartilage	Abundant collagen; no perichondrium	Intervertebral discs, pubic symphysis, knee joints	Shock absorption, tensile strength

Bone (Osseous Tissue)

Structure: Osteocytes in lacunae arranged in osteons; matrix mineralized (Ca, P); highly vascular

Type	Structure	Location	Function
Compact Bone	Dense, solid, has osteons	Shaft of long bones	Strength and support
Spongy Bone	Porous, trabecular, contains red marrow	Ends of long bones, vertebrae	Blood cell production (hematopoiesis), lightweight support

Fluid Connective Tissue

Blood

Structure: Liquid matrix (plasma) with RBCs, WBCs, and platelets
Location: Circulates throughout the body via blood vessels
Functions:

Transport of gases, nutrients, hormones, waste
Protection via immune response (WBCs)
Clotting (platelets)

Component	Function
Red Blood Cells (RBCs)	Carry oxygen using hemoglobin
White Blood Cells (WBCs)	Provide immunity
Platelets	Blood clotting
Plasma	Transports nutrients, hormones, waste

Lymph

Structure: Colorless fluid containing lymphocytes
Location: Lymphatic vessels
Functions:

Drains excess tissue fluid
Transports fats (especially from intestines)
Provides immunity

Comparison Table of Connective Tissues

Type	Matrix	Vascularity	Example	Special Features
Areolar	Loose, gel-like	Highly vascular	Under epithelium	Fills spaces, connects tissues
Adipose	Sparse fibers	Highly vascular	Fat layer (subcutaneous)	Energy storage, insulation
Dense Regular	Collagen, parallel	Poorly vascular	Tendons, ligaments	Tensile strength
Cartilage	Firm but flexible	Avascular	Trachea, ears	Smooth, supportive
Bone	Rigid, mineralized	Highly vascular	Skeleton	Strongest tissue
Blood	Fluid (plasma)	Vascular	Blood vessels	Transport & defense
Lymph	Watery	Flows in lymphatic system	Lymphatic vessels	Immunity, drainage

Muscle Tissue

Muscle tissue is a specialized tissue responsible for producing movement through contraction. It contains contractile proteins — actin and myosin — which enable contraction and relaxation.

Key Features of Muscle Tissue

Feature	Description
Origin	Mesodermal (from mesoderm layer in the embryo)
Main Function	Movement of body parts and internal organs
Key Proteins	Actin and Myosin
Special Properties	Excitability, Contractility, Extensibility, Elasticity

Functions of Muscle Tissue

Function	Explanation
Movement	Skeletal muscles move bones; smooth muscles move food, urine, etc.
Circulation	Cardiac muscle pumps blood; smooth muscles regulate vessel diameter
Posture Maintenance	Skeletal muscles help in standing and sitting
Thermogenesis	Muscular activity generates heat to maintain body temperature
Peristalsis	Smooth muscles help move contents through digestive tract

Types of Muscle Tissue

Type	Structure	Location	Control	Function
1. Skeletal (Striated) Muscle	- Long, cylindrical, unbranched cells - Multinucleated with peripheral nuclei - Striations present - Fast contraction	- Attached to bones - Diaphragm - Tongue	Voluntary	- Body movement - Posture maintenance - Heat generation
2. Cardiac Muscle	- Branched, cylindrical fibers - Uninucleated, central nucleus - Striated - Intercalated discs present - Intermediate speed of contraction	Walls of the heart (myocardium)	Involuntary	- Pumps blood throughout body - Rhythmic contractions (heartbeat)
3. Smooth (Unstriated) Muscle	- Spindle-shaped cells - Single central nucleus - No striations - Slow, sustained contractions	- Internal organs: stomach, intestine, bladder, uterus, blood vessels	Involuntary	- Peristalsis - Regulates blood flow - Uterine contractions

Comparison Table of Muscles

Feature	Skeletal Muscle	Cardiac Muscle	Smooth Muscle
Shape	Long, cylindrical	Branched, cylindrical	Spindle-shaped
Nucleus	Multinucleated, peripheral	Uninucleated, central	Uninucleated, central
Striations	Present	Present	Absent
Control	Voluntary	Involuntary	Involuntary
Speed of Contraction	Fast	Moderate	Slow
Fatigue	Fatigues quickly	Does not fatigue	Does not fatigue
Location	Bones, diaphragm	Heart	Internal organs
Special Features	Quick response, high power	Intercalated discs, rhythmic	Sustained contraction

Important Terms

Striations: Alternating dark and light bands caused by arrangement of actin and myosin (seen in skeletal and cardiac muscle).
Intercalated Discs: Unique junctions in cardiac muscle allowing rapid electrical signal transmission.
Voluntary vs. Involuntary: Skeletal muscles are under conscious control; cardiac and smooth are not.
Fatigue: Skeletal muscles fatigue quickly due to lactic acid buildup; cardiac and smooth do not fatigue easily.

Nervous Tissue

The nervous tissue, containing densely packed cells called neurons, is present in the brain, spinal cord, and nerves. Neurons are specialized for the conduction of nerve impulses. They receive stimuli from within or outside the body and conduct impulses that travel from one neuron to another. This enables voluntary movements and quick responses to stimuli. The functional combination of nervous and muscle tissue is essential for rapid movement in animals.

Structure of a Neuron

Cyton or Cell Body: Contains the nucleus and cytoplasm, with darkly stained Nissl’s granules (ribosomes and rough ER).
Cell Processes:
- Dendrites: Short, branched projections that receive signals and transmit them to the cell body.
- Axon: A single long process that transmits signals away from the cell body to other neurons or effectors. Axons end in terminal branches called telodendria, with synaptic knobs at the ends.

In text question answers

Exercise 6.1

What is a tissue?

Answer: A tissue is defined as a cluster of cells, which are similar in structure and work together to perform a particular function.

What is the utility of tissues in multicellular organisms?

Answer: The use of tissues in multicellular organisms is to provide structural and mechanical strength as well as to allow division of labour.

Exercise 6.2

Name the types of simple tissues.

Answer: The types of simple tissues are as follows:

Parenchyma
Collenchyma
Sclerenchyma

Where is apical meristem found?

Answer: In plants, apical meristem is typically found at:

The tip of the shoot
Root of the plant

Which tissue makes up the husk of a coconut?

Answer: The sclerenchymatous tissue, which is a type of permanent tissue makes up the husk of the coconut. These tissues cause the plant to become stiff and hard. The cells of this tissue are dead and their cell walls are thickened because of the presence of lignin.

What are the constituents of phloem?

Answer: The phloem consists of the following four elements:

Sieve tubes
Companion cells
Phloem parenchyma
Phloem fibres

Exercise 6.3 Page: 77

Name the tissue responsible for movement of our body.

Answer: Two tissues jointly are responsible for the movement of our body, namely:

Muscular tissue
Nervous tissue

What does a neuron look like?

Answer: A neuron is a nerve cell consisting of the cell body with a nucleus and cytoplasm from which a long and thin hair-like structure emerges. Every neuron has one elongated part known as the axon, and several short and small branched structures known as dendrites. A single neuron can even be a meter long

Give three features of cardiac muscles.

Answer: The following are the features of cardiac muscles:

They are cylindrical in shape.
Striated muscle fibers.
They are uninucleated and branched.
These muscles are involuntary in nature.

What are the functions of areolar tissue?

Answer: Areolar tissues are connective tissues found in animals. They are located between the skin and muscles, around blood vessels and nerves, and in the bone marrow. They support internal organs and assist in tissue repair in case of damage. Exercise 4 Page: 78

Define the term ‘tissue’.

Answer: A tissue is defined as a cluster of cells, which are similar in structure and work together to perform a particular function.

How many types of elements together make up the xylem tissue? Name them.

Answer: The xylem tissue is made up of four main elements, namely:

Vessels
Tracheids
Xylem fibres
Xylem parenchyma

How are simple tissues different from complex tissues in plants?

Answer:>

Simple tissues	Complex tissues
Made up of a single type of cell that performs one function	Made up of more than one kind of cell that coordinate to perform one function

Differentiate between parenchyma, collenchyma and sclerenchyma on the basis of their cell wall.

Answer:

Parenchyma	Collenchyma	Sclerenchyma
Cell walls are thin and made up of cellulose	Cell walls are thick at the edges due to pectin	Cell walls are thick due to lignin

What are the functions of the stomata?

Answer: Stomata are pores on the epidermis of leaves. They help in exchange of gases and transpiration.

Show the difference between the three types of muscle fibres diagrammatically.

Answer:

Cardiac muscles: Present in the heart, involuntary, 1 nucleus, branched fibers.
Smooth muscles: Found in lungs and alimentary canal, involuntary, 1 nucleus, spindle-shaped.
Striated muscles: Connected with bones, voluntary, long and cylindrical, multinucleated, unbranched.

What is the specific function of the cardiac muscle?

Answer: Cardiac muscles contract and relax rhythmically to pump blood throughout life. They are involuntary, branched and uninucleated.

Differentiate between striated, un-striated and cardiac muscles on the basis of their structure and site/location in the body.

Answer:

Character	Striated muscles	Un-striated muscles	Cardiac muscles
Shape/Structure	Long, cylindrical, unbranched	Long, tapering, unbranched	Cylindrical, branched
Location in body	Hands, legs, skeletal muscles	Stomach wall, intestines, ureter	Heart
Dark and light bands	Present	Absent	Present but faint

Draw a labelled diagram of a neuron.

Answer: Diagram of a neuron along with the labelling is as follows:

Name the following.

(a) Tissue that forms the inner lining of our mouth.

(b) Tissue that connects muscle to bone in humans.

(c) Tissue that transports food in plants.

(d) Tissue that stores fat in our body.

(e) Connective tissue with a fluid matrix.

(f) Tissue present in the brain.

Answer:

(a) Tissue that forms the inner lining of our mouth – The epithelial tissue, Squamous epithelium.

(b) Tissue that connects muscle to bone in humans – Tendon

(d) Tissue that stores fat in our body – Adipose tissue

(e) Connective tissue with a fluid matrix – Blood, it is a fluid connective tissue

(f) Tissue present in the brain – Nervous tissue

Identify the type of tissue in the following: Skin, bark of tree, bone, lining of kidney tubule, vascular bundle.

Answer:

Skin: Stratified squamous epithelial tissue
Bark of tree: Protective tissue and cork
Bone: Connective tissue
Lining of kidney tubule: Cuboidal epithelial tissue
Vascular bundle: Conducting tissue (xylem and phloem), complex permanent tissue

Name the regions in which parenchyma tissue is present.

Answer:

The pith of stems and roots
In green leaves as chlorenchyma (parenchyma with chlorophyll)
In aquatic plants as aerenchyma (parenchyma with air cavities)

What is the role of epidermis in plants?

Answer: The epidermis in plants forms an uninterrupted and continuous layer that has no intercellular spaces. It provides protection.

How does the cork act as a protective tissue?

Answer: Cork cells are dead. The arrangement of cells is so dense that there is no intercellular space. Deposition of suberin on the walls of the cells makes them impervious to water and gases.

Complete the following chart.

Answer:

Type of Tissue	Location/Function
Parenchyma	Found in stems, roots, leaves; stores food
Collenchyma	Provides flexibility to plant parts
Sclerenchyma	Provides strength and rigidity
Xylem	Conducts water and minerals
Phloem	Transports food

Multiple Choice Questions

The cells of cork are dead and have a chemical in their walls that makes them impervious to gases and water. The chemical is: (a) Lignin (b) Suberin (c) Cutin (d) Wax Answer: (b) Suberin
The flexibility in plants is due to a tissue called: (a) Chlorenchyma (b) Parenchyma (c) Sclerenchyma (d) Collenchyma
Answer: (d) Collenchyma
The tissue present in the lining of kidney tubules and ducts of salivary glands is: (a) Squamous epithelium (b) Glandular epithelium (c) Cuboidal epithelium (d) Columnar epithelium
Answer: (c) Cuboidal epithelium
The connective tissue that connects muscle to bone is called: (a) Ligament (b) Tendon (c) Cartilage (d) Areolar
Answer: (b) Tendon
The tissue that helps in the movement of our body is: (a) Muscular tissue (b) Skeletal tissue (c) Nervous tissue (d) All of the above
Answer: (a) Muscular tissue
Monocyte, basophil, eosinophil, and neutrophil are examples of: (a) Red blood cells (b) White blood cells (c) Areolar tissue (d) Compact bone
Answer: (b) White blood cells
The spindle-shaped cells, uninucleated and unbranched, are present in: (a) Striated muscles (b) Smooth muscles (c) Cardiac muscles (d) Both (a) and (b)
Answer: (b) Smooth muscles
Sieve tubes and companion cells are present in: (a) Xylem (b) Phloem (c) Cork (d) Cambium
Answer: (b) Phloem
The size of the stem increases in width due to: (a) Apical meristem (b) Intercalary meristem (c) Primary meristem (d) Lateral meristem
Answer: (d) Lateral meristem
Blood and lymph are types of: (a) Muscular tissue (b) Epithelial tissue (c) Connective tissue (d) Permanent tissue
Answer: (c) Connective tissue
Cartilage and bone are types of: (a) Muscular tissue (b) Connective tissue (c) Meristematic tissue (d) Epithelial tissue
Answer: (b) Connective tissue
Xylem and phloem are examples of: (a) Epidermal tissue (b) Simple tissue (c) Protective tissue (d) Complex tissue
Answer: (d) Complex tissue
A tissue whose cells are capable of dividing and re-dividing is called: (a) Complex tissue (b) Connective tissue (c) Protective tissue (d) Meristematic tissue
Answer: (d) Meristematic tissue
The tissue that helps in secretion and absorption and is found in the inner lining of the alimentary canal is: (a) Ciliated epithelium (b) Cuboidal epithelium (c) Squamous epithelium (d) Columnar epithelium
Answer: (d) Columnar epithelium