CBSE Class 9 Science Tissues Assignment Set 02

1. Tissue is a group of cells having similar origin, structure& function. Study of tissues is called Histology
2. In unicellular organism (Amoeba) single cell performs all basic functions, whereas in multi-cellular organisms (Plants and Animals) shows division of labor as Plant tissue & Animal tissues.
3. Plant tissues are two types: Meristems & Permanent tissues.
4. Meristems: The Meristems are the tissues having the power of cell division. It is found on those region of the plant which grows.
5. Types of Meristems;

1. The Apical meristems – It is present at the growing tip of the stem and roots and increases the length.
2. The lateral meristems - present at the lateral side of stem anf root (cambium) and increases the girth.
3. The intercalary meristems - present at internodes or base of the leaves and increases the length between the nodes.

Permanent tissues: Two types such as Simple permanent tissues & Complex permanent tissues.

a) Simple permanent tissues: subdivided as

(i): Parenchyma: Tissues provide the support to plants.They are loosly packed and has large intracellular space.

• Parenchyma with chlorophyll which performs photosynthesis is called as chlorenchyma.
• The parenchyma with large air spaces to give buoyancy is called as aerenchyma .Parenchyma also stores food and water.

(ii) Collenchyma: Tissue provides mechanical support, thickened at the corners, have very little intercellular space. It allows easy bending of various parts of a plants without
breaking

(iii) Sclerenchyma: Tissue makes the plant hard and stiff, thickened due to lignin and no intercellular space. Cells of this tissue are dead and commonly seen in the husk of coconut.

(iv) Guard cells& Epidermal tissue: the tissue aids in protection and exchange of gases. Guard cells kidney shaped in dicots, dumb bell shaped in monocots to guard the stomata. The epidermal tissues of roots aid in absorption of water and minerals. The epidermal tissues in desert plants have a thick waxy coating of Cutin with waterproof quality. The epidermal tissues form the several layer thick Cork or the Bark of the tree.

b) Complex permanent tissues: The complex tissues are made of more than one type of cells. All these cells coordinate to perform a common function.

They are subdivided as;

Xylem: It consists of tracheids, vessels, xylem parenchyma and xylem fibers. The cells have thick walls,

Function - aids in conduction of water and minerals.

Phloem: It consists of sieve tubes, companion cells, phloem parenchyma, and phloem fibers.

Function - Phloem transports food material to other parts of the plants.

6. Animal tissues: Sub divided as epithelial tissue, connective tissue, muscular tissue and nervous tissue.

i. Epithelial tissue: It is a protective covering forming a continuous sheet. Simple epithelium is the one which is extremely thin in one layer, whereas stratified epithelium are arranged in pattern of layers.

Depending on shape and function they are classified as:

a) Squamous epithelium in the lining of mouth and esophagus.
b) Cuboidal epithelium in the lining of kidney tubules and salivary glands.
c) Columnar epithelium in the intestine &Columnar epithelium with cilia in the lining of respiratory tract.
d) Glandular epithelium in the Glands aids in a special function as gland cells, which can secrete at the epithelial surface.

ii) Connective Tissue: Five Types, such as;

a) Blood: The Blood is a fluid connective tissue. Blood plasma has RBCs (Red Blood Cells) WBCs (White Blood Cells) and platelets. Blood plasma contains proteins, salts and hormones. Blood flows and transports gases, digested food, hormones and waste materials.

b) Bone: The bone is a connective tissue with hard matrix, composed of calcium and phosphorus. A bone is connected by another bone with another connective tissue called ligaments. A bone is connected by muscle with another connective tissue called tendon.

c) Cartilage: The cartilage is a connective tissue with solid matrix composed of proteins and sugars. It is commonly seen in nose, ear, trachea, and larynx.

d) Areolar Connective Tissue: It is found between the skin and muscles, around the blood vessels. It supports internal organs and aids in repair of tissues.

e)Adipose Connective Tissue: It is filled with fat globules for the storage of fat. It acts as insulator.

Muscular tissues: They have special contractile proteins responsible for movements. Three types, such as;

Striated muscles/skeletal muscles/voluntary muscles :

They are cylindrical, un-branched and multinucleated.They have dark bands and light bands.

Unstriated muscles/smooth muscles/involuntary muscles:
They are commonly called as Smooth muscles, having no striations (dark bands/ light bands are absent). Commonly found alimentary canal, uterus, Iris of an Eye. They are spindle shaped. Involuntary in nature

Cardiac Muscles: They are commonly called as Heart muscles, cylindrical, branched and uni-nucleate. Involuntary in nature

Nervous Tissue: The tissue responds to stimuli. The brain, spinal cord and nerves are composed of nervous tissue or neurons. A neuron consists of Cell Body, cytoplasm, Nucleus, Dendrite, Axon, nerve ending. The neuron impulse allow us to move our muscles when we want to respond to stimuli.

Exam Questions NCERT Class 9 Science Chapter 6 Tissue

Question. Explain the structure of parenchyma. What are its major modifications?
Ans : Parenchyma : It is the basic or fundamental tissue found in plants. Cells of this tissue are thin walled, circular or polygonal. They are living with a nucleus and a vacuole. Intercellular spaces are present between the cells of this tissue. Two modifications of parenchyma are chlorenchyma and aerenchyma.
(a) Chlorenchyma : Sometimes cells of the parenchyma contain chlorophyll and perform photosynthesis. This kind of parenchyma is known as chlorenchyma.
(b) Aerenchyma : In aquatic plants, parenchyma contains big air spaces in between them. Such a parenchyma tissue is known as aerenchyma.

Question. What is xylem? Explain its structure. Which one of its component is very important and why?
Ans : Xylem is a complex plant tissue which transports water and dissolved minerals from roots to all other plant parts. Structure : Xylem consists of four kinds of cells (also known as elements). Tracheids : A tracheid is an elongated, hollow cell with its both ends tapering. The walls of these cells are thick by the deposition of lignin. At certain spots lignin is not present. These spots are termed as pits. The tracheids are dead cells. Vessels : These are tube-like structures formed by a number of cells placed end to end with their transverse walls dissolved. The side walls of these tubes also have deposition of lignin. The thickening of the walls show various kinds of patterns. They are also dead cells. Xylem Parenchyma : They are prenchymatous, thin walled, living cells. They help in lateral conduction of water and sap. They also store food. Xylem Fibres : They are lignified dead fibres which provide mechanical support to plant. The most important element of xylem is vessel because most of the water and minerals are carried upward through this component of xylem.

Question. Write the various functions of all types of epithelial tissues?
Ans : Epithelial tissues help in protection, absorption, excretion, exchange of respiratory gases and secretion.

Question. Explain connective tissue along with its types.
Ans : Connective tissue consists various types of cells which perform the same function. These are of three types :
(i) Proper connective tissue
(ii) Fluid tissue
(iii) Skeletal tissue
Proper connective tissue : These are of four types–
Areolar and ligament connective tissue : It is present between muscles and skin and in the bone marrow. It is also present around nerves and blood vessels. They fill the space inside the organ. They also provide strength to internal organs and helps in repair of tissues.
Adipose tissue : It is found below the skin and also between internal organs. It stores fat and due to this fat storage, it behaves as an insulator.
Tendon : It is fibrous, strong and flexible and joins muscles with bone.
Ligament : It is elastic and strong and joins bone with bone.
Fluid tissue consists of :
Blood : It is a liquid tissue called plasma which has RBCs, WBCs, plasma and blood platelets. It helps to transport substances like gases, hormones, digested food and waste material. Lymph : It transports digested fat and white blood cells in plasma.
Skeletal tissue is made up of :
Bone : It is a hard tissue which helps in the movement and support of our body.
Cartilage : It softens the bone surface at joints. It is found in our ear, nose, trachea and larynx.

Question. Where is chlorenchyma tissue present?
Ans : It is present in the centre of stems and roots. If it has chlorophyll then it is called chlorenchyma. It is present in green leaves.

Question. What are three main categories of connective tissue?
Ans : Categories of connective tissue are : Connective tissue proper : There is a matrix in which generally two types of (white and yellow) fibres are present. In between these fibres some connective tissue cells are present. Example of this kind of connective tissues are aerolar tissue and adipose tissue. Skeletal tissue : This type of tissues form the skeleton of an organism. It is of two types : Cartilage and bone. a. Cartilage has solid matrix called chondrin, in which fibres and cells known as chondrocytes are present. Usually cells are present in clusters of 2-3 cells in small spaces called lacunae. Cartilage is found in the regions of pinna, nose, trachea and larynx. b. In bones, matrix is formed of a protein called ossein impregnated with phosphate and carbonates of calcium and magnesium. Fluid tissue : Blood and lymph are examples of fluid connective tissues. These are specialized connective tissues. It consists of liquid matrix with no fibres. In liquid matrix called plasma corpuscles remain suspended. Blood transports food material, gases and other substances to the various parts of the body.

Question. Write the main functions of collenchyma?
Ans : The main functions of collenchyma are to provide mechanical support, tensile strength, elasticity and flexibility to stem, leaf stalks and leaves.

Question. What is basement membrane?
Ans : It is very thin non-cellular membrane on which cells of epithelial tissue rest. It also separates the epithelial tissue from the underlying tissues.

Question. Describe the structure of phloem.
Ans : Structure of phloem : The main conducting part of the phloem is sieve tube which is formed of elongated cylindrical cells arranged in vertical rows. The walls between the cells have many minute pores through which food material can pass from one cell to the next. The porous walls between the cells is termed as sieve plate. Each sieve tube member is supported by a long parenchymatous cell called companion cell which helps the sieve tubes in the conduction of food material. Phloem also contains phloem fibres, which provide support. Another component of phloem is parenchyma cells which stores food.

Question. What is the use of tissues in multicellular organisms?
Ans : Tissue provides structural and mechanical strength as well as to allow division of labour in multicellular organisms.

Question. Describe the structure of cartilage and bone.
Ans : Cartilage : It is a solid but semi-rigid and flexible connective tissue. It has large bluntly angular cartilage cells called chondrocytes. They occur in clusters of 2 and 3 in small spaces (lacunae) scattered in the matrix. Cartilage smoothens bone surfaces at joints and is also present in the nose, ear, trachea and larynx. Bone : Bone is a solid, rigid and strong connective tissue. Its matrix become hard due to the deposition of salts of calcium and phosphorous. Osteocytes or bone cells are present in irregular spaces lacunae in the matrix, interconnected by fine canals called canaliculi. In this tissue, matrix deposits in concentric rings around narrow longitudinal cavities called haversian canals. These canals carries blood vessels and nerves.

Click on link below to download CBSE Class 9 Science Tissues Assignment Set B

Question 1. Give atleast two locations where cartilaginous connective tissue is present in our body.
Answer: Cartilaginous connective tissue (cartilage) is found in the tip of the nose, outer ear pinna, trachea (windpipe), bronchi, and at the joints of bones.
In simple words: Cartilage is a flexible connective tissue found in body parts that need to bend and support weight, like the nose and ears.

Exam Tip: Memorize at least two clear examples such as the ear pinna and the tip of the nose for full credit.

Question 2. What are the other names of striated muscles?
Answer: Striated muscles are also known as skeletal muscles or voluntary muscles.
In simple words: They are called skeletal because they are attached to bones, and voluntary because we can control their movement consciously.

Exam Tip: Always mention both skeletal muscles and voluntary muscles to show thorough understanding.

Question 3. What is middle lamella?
Answer: The middle lamella is a calcium and magnesium pectate layer that cements or glues adjacent plant cells together.
In simple words: It acts like an intercellular glue holding neighboring plant cell walls together.

Exam Tip: Mentioning its chemical composition (calcium pectate) guarantees full marks.

Question 4. Name the meristematic tissue, which increases the thickness of plants.
Answer: Lateral meristem (such as cambium) increases the thickness or girth of plants.
In simple words: Lateral meristems make plant stems and roots grow wider.

Exam Tip: Distinguish clearly between apical meristem (length) and lateral meristem (thickness/girth).

Question 5. Which tissue makes up the husk of coconut?
Answer: Sclerenchymatous tissue makes up the husk of a coconut.
In simple words: The tough, fibrous husk is made of dead, thick-walled sclerenchyma cells.

Exam Tip: Specify that it is dead sclerenchyma tissue containing lignin.

Question 6. Write two functions of stomata?
Answer: (1) Exchange of gases (oxygen and carbon dioxide) during respiration and photosynthesis.
(2) Transpiration (loss of water vapor in the form of water) which helps in the upward movement of water and minerals.
In simple words: Stomata are tiny pores that let plants breathe and release excess water.

Exam Tip: Clearly list two distinct functions: gas exchange and transpiration.

Question 7. How does a neuron look like?
Answer: A neuron consists of a central cell body (cyton) containing a nucleus and cytoplasm, from which hair-like extensions called dendrites arise, and a long, single tail-like fiber called the axon.
In simple words: A neuron looks like a star-shaped cell body with branching fingers (dendrites) and a long tail (axon).

Exam Tip: Mention cyton, dendrites, and axon to secure full credit.

Question 8. Where is apical meristem found?
Answer: Apical meristem is found at the growing tips of stems and roots (apex of roots and shoots).
In simple words: It is located right at the very tips where plants grow longer.

Exam Tip: State both root apex and shoot apex.

Question 9. Name types of simple plant tissues.
Answer: The three main types of simple permanent plant tissues are Parenchyma, Collenchyma, and Sclerenchyma.
In simple words: Simple tissues are made of only one type of cell performing similar functions.

Question 10. Write a brief note on muscle tissue?
Answer: Muscle tissue consists of elongated cells called muscle fibers, which are responsible for movement in the body. They contain special contractile proteins called actin and myosin that slide past each other to cause contraction and relaxation. Muscle tissue is classified into three types: striated (skeletal), unstriated (smooth), and cardiac muscles.
In simple words: Muscle tissue is made of special fiber cells that contract and relax to move body parts.

Exam Tip: Mention contractile proteins and the three main categories to earn full marks.

Question 11. What is phloem parenchyma?
Answer: Phloem parenchyma are living, elongated parenchymatous cells associated with the phloem tissue. Their main function is the storage of food materials (like starch, fats, and resins) and lateral conduction of food.
In simple words: These are living storage cells found inside the food-conducting phloem tissue.

Exam Tip: Emphasize that they are living cells specialized for food storage.

Question 12. Draw a diagram of a neuron.
Answer:
Steps to draw:
1. Draw a central star-shaped or polygonal cell body (cyton) with a nucleus.
2. Draw short, branching projections (dendrites) emerging from the cell body.
3. Draw a long cylindrical process (axon) extending from the cell body, covered with myelin sheaths.
4. End the axon with branched nerve endings (axon terminals).
In simple words: A labeled diagram showing cell body, dendrites, axon, and nerve terminals.

Exam Tip: Always label the nucleus, cell body, dendrites, and axon clearly.

Question 13. Name the following.
a) Tissue that forms the inner lining of our mouth.
b) Tissue that connects muscle to bone in human.
c) Tissue that transports food in plants.
d) Tissue that stores fat in our body.
Answer:
a) Squamous epithelium
b) Tendon
c) Phloem
d) Adipose tissue
In simple words: (a) Squamous lining, (b) Tendon connects muscle to bone, (c) Phloem carries food, (d) Adipose stores fat.

Exam Tip: Be precise with terminology (e.g., use tendon, not ligament for muscle-to-bone connection).

Question 14. What is the composition of blood?
Answer: Blood is a fluid connective tissue composed of a fluid matrix called plasma (about 55%) and formed elements or blood cells (about 45%). The blood cells include Red Blood Cells (erythrocytes), White Blood Cells (leucocytes), and Blood Platelets (thrombocytes).
In simple words: Blood is made of liquid plasma carrying red cells, white cells, and platelets.

Exam Tip: Mention plasma and the three types of blood cells for complete marks.

Question 15. How many types of tissues are found in animals?
Answer: Animal tissues are broadly classified into four main types:
(1) Epithelial tissue
(2) Connective tissue
(3) Muscular tissue
(4) Nervous tissue
In simple words: Animals have four basic tissue types covering surfaces, connecting parts, enabling movement, and transmitting signals.

Question 16. What are the functions of areolar tissue?
Answer: (1) It acts as a supporting and packing tissue between organs inside the body cavity.
(2) It helps in the repair of tissues after injury.
(3) It fixes skin to underlying muscles.
In simple words: Areolar tissue fills space inside organs and helps repair damaged tissues.

Exam Tip: Remember that areolar tissue is found between skin and muscles, around blood vessels and nerves.

Question 17. How many types of elements together makeup the xylem tissue? Name them.
Answer: Xylem is made up of four types of elements:
(1) Tracheids
(2) Vessels (Tracheae)
(3) Xylem parenchyma
(4) Xylem fibers (sclerenchyma)
In simple words: Xylem consists of four components that help transport water and provide structural support.

Exam Tip: List all four elements correctly and note that only xylem parenchyma is living among them.

Question 18. What are the constituents of phloem?
Answer: Phloem is composed of four constituents:
(1) Sieve tubes
(2) Companion cells
(3) Phloem parenchyma
(4) Phloem fibers (bast fibers)
In simple words: Phloem consists of four cell types responsible for transporting food in plants.

Question 19. Name the fluid connective tissue in humans. What are its various constituents?
Answer: The fluid connective tissue in humans is blood. Its constituents are plasma (fluid matrix) and blood cells (RBCs, WBCs, and platelets).
In simple words: Blood is our fluid tissue, made of liquid plasma and floating blood cells.

Exam Tip: State both plasma and blood cells clearly.

Question 20. "Multi-cellular organisms show division of labour." Comment.
Answer: In multicellular organisms, different groups of cells specialize to perform specific, distinct functions efficiently. For example, muscle cells contract for movement, nerve cells transmit impulses, and red blood cells transport oxygen. This specialization and sharing of workload among different cells and tissues is known as division of labour.
In simple words: Just like different workers have different jobs in a factory, different cells in a multicellular body perform specific tasks.

Exam Tip: Use the term "cell specialization" to explain division of labour effectively.

Question 21. How does the cork act as a protective tissue?
Answer: Cork cells are dead and compactly arranged without intercellular spaces. Their cell walls are impregnated with a chemical substance called suberin, which makes them impervious to gases and water, protecting the plant against mechanical injury, infection, and water loss.
In simple words: Cork forms a waterproof, tightly sealed protective outer layer on old trees.

Exam Tip: Always mention "suberin" as the chemical responsible for making cork waterproof.

Question 22. State two points of differences between bone and cartilage.
Answer:
(1) Bones are hard, rigid, and non-flexible, whereas cartilage is soft, elastic, and flexible.
(2) Bone matrix is rich in calcium and phosphorus compounds, whereas cartilage matrix contains proteins and sugars.
In simple words: Bones are hard and stiff with calcium, while cartilage is flexible and rubbery.

Question 23. Complete the table:
Answer:
Top box: Parenchyma Cells
Left middle box: Simple permanent tissue
Right middle box: Complex permanent tissue
Lower boxes under Simple: Parenchyma, Collenchyma, Sclerenchyma
Lower boxes under Complex: Xylem, Phloem
In simple words: Plant tissues branch into simple (parenchyma, collenchyma, sclerenchyma) and complex (xylem, phloem) categories.

Exam Tip: Practice plant tissue classification flowcharts regularly.

Question 24. Distinguish between xylem tissue and phloem tissue.
Answer:
 

In simple words: Xylem carries water upward, while phloem carries food in both directions.

Exam Tip: Always include the direction of transport (unidirectional vs. bidirectional) as a key difference.

Question 25. What is cork? Mention its uses.
Answer: Cork is a protective secondary tissue formed by the cork cambium in older woody plants/trees, consisting of dead cells filled with suberin.
Uses:
(1) Used as bottle stoppers.
(2) Used for insulation and in shock absorbers due to its lightweight and compressible nature.
In simple words: Cork is the protective outer bark used for bottle caps and insulation.

Exam Tip: Mention both its botanical definition and practical industrial uses.

Question 26. What are the functions of bone, cartilage and ligament?
Answer:
(1) Bone: Provides skeletal framework, supports body weight, anchors muscles, and protects vital internal organs.
(2) Cartilage: Provides support and flexibility to body parts (like nose, ear, joints) and smooths bone surfaces at joints.
(3) Ligament: Connects bone to bone, providing stability to joints.
In simple words: Bones support the body, cartilage gives flexible support, and ligaments tie bones together.

Exam Tip: Remember: Ligaments connect bone to bone, while tendons connect muscle to bone.

Question 27. Give three features of cardiac muscles.
Answer:
(1) They are involuntary muscles found exclusively in the heart walls.
(2) They are striated (striped) and branched cells that fuse together.
(3) They rhythmically contract and relax throughout life without getting fatigued.
In simple words: Heart muscles are involuntary, branched, striated, and never get tired.

Exam Tip: Emphasize that they never fatigue, unlike skeletal muscles.

Question 28. What is the utility of the tissues in multi-cellular organisms?
Answer: Tissues provide structural strength, mechanical support, and division of labour in multicellular organisms. By dividing tasks among specialized tissues, organs function efficiently, enabling complex organisms to survive and perform vital life processes.
In simple words: Tissues divide work so that different body parts can function efficiently.

Exam Tip: Use key terms like "division of labour" and "efficiency".

Question 29. What is the role of epidermis in plants?
Answer: (1) It provides protection against mechanical injury, fungal infection, and water loss.
(2) Stomata present in the epidermis allow gaseous exchange and transpiration.
(3) Root epidermis helps in water and mineral absorption.
In simple words: Epidermis is the outermost protective skin of the plant.

Exam Tip: Mention protection, stomatal gas exchange, and absorption.

Question 30. (i) Name the living component common to both the complex permanent tissues found in plants. What is its function?
(ii) State any two ways in which these tissues differ functionally from each other.
Answer:
(i) The living component common to both xylem and phloem is parenchyma (Xylem parenchyma and Phloem parenchyma). Its function is the storage of food and lateral conduction.
(ii) Functional differences:
1. Xylem transports water and dissolved minerals from roots to leaves, whereas phloem transports synthesized organic food from leaves to other plant parts.
2. Transport in xylem is unidirectional, whereas transport in phloem is bidirectional.
In simple words: (i) Parenchyma stores food. (ii) Xylem moves water upward, while phloem moves food both ways.

Exam Tip: Clearly address both parts of the question to secure full marks.

Question 31. Identify the type of tissue in the following and state one function of each:
(i) Skin
(ii) Heart muscles
(iii) Lining of Kidney tubule
Answer:
(i) Skin: Stratified squamous epithelial tissue - protects underlying body parts against mechanical damage and germs.
(ii) Heart muscles: Cardiac muscle tissue - pumps blood rhythmically throughout the body.
(iii) Lining of Kidney tubule: Cuboidal epithelial tissue - provides mechanical support and helps in reabsorption of useful materials.
In simple words: (i) Skin protects, (ii) Heart muscle pumps blood, (iii) Kidney tubule epithelium aids reabsorption.

Exam Tip: Specify the exact epithelial subtype (e.g., stratified squamous or cuboidal) for full marks.

Question 32. (i) "Epidermal cells are protective in nature". Justify and support your answer with two examples.
(ii) Name the structure that receives impulse in neuron.
Answer:
(i) Epidermal cells form the outermost continuous layer of plants and secrete a waxy, water-resistant layer (cuticle) that prevents water loss and entry of pathogens. Examples: (1) Cuticle layer on desert plants to prevent transpiration; (2) Cork cells on old stems acting as a thick protective bark.
(ii) Dendrites receive nerve impulses.
In simple words: (i) Epidermis protects against water loss and germs (e.g., cuticle and cork). (ii) Dendrites receive nerve signals.

Exam Tip: Always mention the cuticle and cork when discussing epidermal protection.

Question 33. What are the functions of connective tissue?
Answer: Connective tissues bind, support, and pack together other tissues and organs of the body. Their main functions include:
(1) Binding: Tendons connect muscles to bones, and ligaments connect bone to bone.
(2) Support: Bones and cartilage form the skeletal framework supporting the body.
(3) Transportation: Blood transports oxygen, nutrients, hormones, and wastes.
(4) Protection: Bones protect delicate internal organs like the brain and heart; adipose tissue acts as a shock absorber.
(5) Defense: White blood cells fight infections.
In simple words: Connective tissue connects body parts, supports the skeleton, transports fluids, and protects organs.

Exam Tip: Categorize functions into binding, support, transport, and protection for a well-structured 5-mark answer.

Question 34. What are the differences between striated, unstriated and cardiac muscles?
Answer:
 

In simple words: Striated muscles move limbs voluntarily; unstriated muscles control internal organs involuntarily; cardiac muscles pump the heart rhythmically.

Exam Tip: Presenting differences in a tabular format is the best way to secure full marks in 5-mark comparative questions.

Question 35. Differentiate between:
(a) Simple tissue and complex tissue
(b) Parenchyma, collenchyma and sclerenchyma
Answer:
(a) Simple tissue vs Complex tissue:
- Simple tissues are made of only one type of cell that performs a uniform function (e.g., parenchyma).
- Complex tissues are made of more than one type of cell working together to perform a common function (e.g., xylem and phloem).
(b) Parenchyma, Collenchyma, and Sclerenchyma:
- Parenchyma: Living cells with thin cell walls; provides storage and photosynthesis.
- Collenchyma: Living cells with unevenly thickened corners (pectin/cellulose); provides mechanical support and flexibility.
- Sclerenchyma: Dead cells with thick lignified walls; provides extreme hardness and rigidity.
In simple words: (a) Simple tissues have one cell type; complex tissues have multiple cell types. (b) Parenchyma is thin and soft, collenchyma is flexible, sclerenchyma is dead and hard.

Question 36. (i) Name the plant tissue found in the husk of a coconut.
(ii) Identify the chemical that is responsible for its stiffness.
(iii) Give three ways in which it differs from parenchymatous cells.
Answer:
(i) Sclerenchyma tissue.
(ii) Lignin.
(iii) Differences from parenchyma:
1. Sclerenchyma cells are dead at maturity, whereas parenchyma cells are living.
2. Sclerenchyma cell walls are extremely thick due to lignin deposition, whereas parenchyma walls are thin and made of cellulose.
3. Sclerenchyma provides mechanical rigidity and strength, whereas parenchyma stores food and water.
In simple words: (i) Sclerenchyma. (ii) Lignin. (iii) Sclerenchyma cells are dead, thick-walled, and rigid, unlike living, thin-walled parenchyma.

Exam Tip: Mention lignin and dead cell nature for guaranteed marks.

Question 37. Give one term for the following:
(i) Structure that takes impulses away from a neuron.
(ii) Meristematic tissue that increases the girth in plants.
(iii) Space found between the cells of the connective tissue.
(iv) Small pores found on the epidermis of a plant leaf.
(v) Protective covering of various organs in animals.
Answer:
(i) Axon
(ii) Lateral meristem
(iii) Matrix / Intercellular space
(iv) Stomata
(v) Epithelial tissue
In simple words: (i) Axon, (ii) Lateral meristem, (iii) Matrix, (iv) Stomata, (v) Epithelium.

Exam Tip: One-word answers must be exact and scientifically accurate.

Question 38. Answer each of the following in one word or one sentence:
(i) What makes the bone matrix hard?
(ii) Which tissue is responsible for moving our hands up and down?
(iii) Name the part of phloem that is nucleated.
(iv) Give another term for striated muscles.
(v) Name the only living cell of xylem.
Answer:
(i) Calcium and phosphorus compounds.
(ii) Striated muscle tissue (skeletal muscle).
(iii) Companion cell.
(iv) Skeletal muscles (or voluntary muscles).
(v) Xylem parenchyma.
In simple words: (i) Calcium/phosphorus, (ii) Striated muscle, (iii) Companion cell, (iv) Skeletal muscle, (v) Xylem parenchyma.

Exam Tip: Keep answers crisp and strictly within one word or sentence as requested.

Most Important Questions

Question 1. What is meristem?
Answer: Meristem is a plant tissue consisting of actively dividing cells responsible for plant growth.
In simple words: Meristem is the growth tissue containing cells that constantly divide to make the plant grow.

Exam Tip: Highlight "actively dividing cells" in your definition.

Question 2. What is tissue?
Answer: A tissue is a group of cells having similar structure and origin that work together to perform a specific function.
In simple words: A tissue is a team of similar cells working together to do a particular job.

Exam Tip: Mention both similar structure and common function.

Question 3. Name the two types of elements found in phloem.
Answer: Sieve tubes and companion cells (or phloem parenchyma and phloem fibers).
In simple words: Main phloem elements include sieve tubes and companion cells.

Question 4. Name two specialized kinds of parenchyma.
Answer: Chlorenchyma and aerenchyma.
In simple words: Chlorenchyma (does photosynthesis) and aerenchyma (stores air in aquatic plants).

Exam Tip: Chlorenchyma contains chlorophyll; aerenchyma provides buoyancy in aquatic plants.

Question 5. Name the main components of xylem. Which out of them is most suitable for carrying water?
Answer: Main components: Tracheids, vessels, xylem parenchyma, and xylem fibers. Vessels and tracheids are most suitable for carrying water due to their tube-like, hollow structure.
In simple words: Xylem components are tracheids, vessels, parenchyma, and fibers, with vessels/tracheids carrying water.

Exam Tip: Specify vessels and tracheids as the primary water-conducting channels.

Question 6. What is permanent tissue?
Answer: Permanent tissues are plant tissues formed by meristematic tissues that have lost their ability to divide and have attained a permanent shape, size, and function.
In simple words: Permanent tissues are mature plant cells that have stopped dividing and taken on specific roles.

Exam Tip: Mention that they originate from meristematic tissue and have lost the capacity for division.

Question 7. Name the term for the cells having shape and size like parenchyma cells but can do photosynthesis.
Answer: Chlorenchyma.
In simple words: Parenchyma cells containing chlorophyll that perform photosynthesis are called chlorenchyma.

Exam Tip: Do not confuse chlorenchyma with collenchyma.

Question 8. What is the difference between apical, lateral and intercalary meristem?
Answer:
- Apical meristem: Found at root and shoot tips; increases plant length.
- Lateral meristem: Found along the sides of stems/roots; increases girth/thickness.
- Intercalary meristem: Found at internodes or leaf bases; increases length of organs like leaves and stems.
In simple words: Apical increases height, lateral increases thickness, and intercalary grows internodes/leaves.

Exam Tip: Clearly state the location and specific growth function for each meristem.

Question 9. Why tissues are important in multicellular organisms?
Answer: Tissues ensure division of labour, allowing different cell groups to specialize in specific functions, thereby increasing the efficiency and survival of multicellular organisms.
In simple words: Tissues divide work so complex organisms can function efficiently.

Question 10. What is the function of collenchyma in plants?
Answer: Collenchyma provides mechanical support, tensile strength, and flexibility to plant parts (like young stems and leaf stalks), allowing them to bend easily without breaking.
In simple words: Collenchyma gives flexible support to young plant parts so they don't break in the wind.

Exam Tip: Emphasize both mechanical support and flexibility.

Question 11. Which tissue makes the plant hard and stiff and what is the unique property of this tissue?
Answer: Sclerenchyma tissue makes the plant hard and stiff. Its unique property is that its cells are dead at maturity with heavily lignified, thick cell walls.
In simple words: Sclerenchyma provides rigidity because its cells are dead and filled with woody lignin.

Question 12. What is the function of epidermis in plants?
Answer: The epidermis protects the plant against water loss, mechanical injury, and pathogen invasion, and facilitates gaseous exchange through stomata.
In simple words: Epidermis acts as a protective outer skin preventing water loss and germ entry.

Exam Tip: List protection, prevention of water loss, and gas exchange.

Question 13. Which structures of the plant are responsible for exchange of gases and where are these located?
Answer: Stomata are responsible for the exchange of gases, and they are located in the epidermis of leaves and young green stems.
In simple words: Stomata are tiny breathing pores located on the surface of leaves.

Exam Tip: Specify stomata and their epidermal leaf location.

Question 14. What are the properties of xylem tracheids and vessels?
Answer: Tracheids and vessels are tubular, dead cells with thick lignified walls that form continuous channels for upward water and mineral transport.
In simple words: They are hollow, dead, tube-like pipes that transport water efficiently from roots to leaves.

Exam Tip: Mention that they are dead, tubular, and have lignified walls.

Question 15. What is the function of phloem?
Answer: Phloem transports manufactured organic food (sugars) from the leaves to storage organs and growing regions of the plant.
In simple words: Phloem transports food produced in leaves to all parts of the plant.

Exam Tip: State clearly that phloem transports food.

Question 16. Give two examples of lateral meristem.
Answer: Cork cambium and vascular cambium.
In simple words: Vascular cambium and cork cambium are lateral meristems that increase stem thickness.

Exam Tip: Name vascular cambium and cork cambium.

Question 17. What are the components of phloem?
Answer: Sieve tubes, companion cells, phloem parenchyma, and phloem fibers.
In simple words: Sieve tubes, companion cells, phloem parenchyma, and phloem fibers make up the phloem.

Question 18. What is the function of xylem parenchyma and xylem fibres?
Answer: Xylem parenchyma stores food and helps in lateral conduction of water. Xylem fibers provide mechanical strength and support to the plant.
In simple words: Parenchyma stores food, while fibers provide structural strength.

Exam Tip: Distinguish between the storage role of parenchyma and the supporting role of fibers.

Question 19. What is the unique property of sieve tubes?
Answer: Sieve tubes are living tubular cells perforated with porous sieve plates at their end walls, and they lack a nucleus at maturity.
In simple words: Sieve tubes are food-conducting tubes with perforated end walls and no nucleus.

Exam Tip: Mention sieve plates and absence of a nucleus in mature sieve tube elements.

Question 20. Name the four types of animal tissues.
Answer: Epithelial tissue, connective tissue, muscular tissue, and nervous tissue.
In simple words: The four fundamental animal tissues are epithelial, connective, muscular, and nervous.

Exam Tip: List all four animal tissue types accurately.

Question 21. Where is cuboidal epithelium located?
Answer: Cuboidal epithelium is located in kidney tubules, salivary gland ducts, and thyroid gland follicles.
In simple words: It is found lining kidney tubules and gland ducts.

Exam Tip: Kidney tubules and gland ducts are the standard examples to quote.

Question 22. What is the function of ligament?
Answer: Ligaments connect bone to bone, providing elasticity, stability, and strength to joints.
In simple words: Ligaments tie bones together at joints.

Exam Tip: Remember: Ligament = Bone to Bone.

Question 23. Mention two special properties of nervous tissue.
Answer: (1) Excitability (ability to respond to stimuli) and (2) Conductivity (ability to transmit electrical impulses rapidly across the body).
In simple words: Nervous tissue can sense stimuli and transmit electrical signals quickly.

Exam Tip: Use the scientific terms excitability and conductivity.

Question 24. Name the tissue in which the matrix is not produced by the cells present in it.
Answer: Blood (fluid connective tissue, where plasma is not secreted by blood cells).
In simple words: Blood cells do not secrete their liquid matrix (plasma).

Exam Tip: Blood is the classic exception where matrix proteins are produced by the liver, not the circulating blood cells.

Question 25. What is the function of blood?
Answer: Blood transports oxygen, carbon dioxide, nutrients, hormones, and waste products, and helps in body defense and temperature regulation.
In simple words: Blood transports gases and nutrients throughout the body and fights disease.

Exam Tip: Mention transport of gases/nutrients and defense against infections.

Question 26. What are the different types of epithelial tissue?
Answer: Squamous epithelium, cuboidal epithelium, columnar epithelium, ciliated epithelium, and glandular epithelium.
In simple words: Epithelial tissues include squamous, cuboidal, columnar, ciliated, and glandular types.

Exam Tip: List the primary structural forms of epithelial tissue.

Question 27. Which tissue is responsible for the transportation of the substances by lining blood vessels or lung alveoli?
Answer: Simple squamous epithelium.
In simple words: Simple squamous epithelium forms delicate linings for easy substance transport.

Exam Tip: Specify "simple squamous epithelium" for precise scoring.

Question 28. What is the function of columnar epithelium in respiratory tract?
Answer: Columnar epithelium (often ciliated) in the respiratory tract helps in moving mucus and trapped dust particles upward out of the respiratory tract.
In simple words: Its cilia beat rhythmically to push mucus and dust out of our airways.

Exam Tip: Mention ciliated columnar epithelium and mucus clearance.

Question 29. Why are glandular epithelial tissues important?
Answer: Glandular epithelial tissues specialize in secreting useful substances such as sweat, saliva, mucus, and digestive enzymes.
In simple words: They form glands that secrete important fluids like sweat and hormones.

Question 30. Write the function of areolar tissue.
Answer: Areolar tissue supports internal organs, repairs injured tissues, and acts as a packing tissue between organs.
In simple words: It fills space between organs and helps repair damaged tissues.

Exam Tip: Mention packing and tissue repair.

Question 31. What is the property of cartilage?
Answer: Cartilage is a smooth, elastic, and flexible connective tissue that cushions joints and provides flexible support.
In simple words: Cartilage is rubbery, flexible, and cushions bone joints.

Exam Tip: Highlight flexibility and smooth joint cushioning.

Question 32. Which tissue stores fats in our body?
Answer: Adipose tissue.
In simple words: Adipose tissue is fat-storing tissue found beneath the skin.

Exam Tip: Adipose tissue also acts as an insulator against heat loss.

Question 33. Which tissue is responsible for the movement of the body?
Answer: Muscular tissue.
In simple words: Muscular tissue contracts and relaxes to move body parts.

Exam Tip: State muscular tissue clearly.

Question 34. Write the properties of voluntary muscles.
Answer: Voluntary muscles (skeletal muscles) are striated, multinucleated, cylinder-shaped, attached to bones, and under our conscious control.
In simple words: They are striped muscles that we can move whenever we want.

Exam Tip: Mention striations, multinucleated condition, and conscious control.

Question 35. Where are involuntary muscles located and what are their fuctions?
Answer: Involuntary muscles (smooth muscles) are located in the walls of internal organs like the stomach, intestine, blood vessels, and bronchi. Their function is to regulate involuntary movements such as peristalsis in the alimentary canal.
In simple words: They control automatic movements in internal organs like the stomach and blood vessels.

Exam Tip: Mention internal organ walls and automatic functions like peristalsis.

Question 36. Why cardiac muscles are unique?
Answer: Cardiac muscles are unique because they are involuntary striated muscles that contract and relax rhythmically throughout a person's life without ever getting fatigued.
In simple words: They are unique because they beat continuously for a lifetime without getting tired.

Exam Tip: Highlight their non-fatiguing, rhythmic contraction.

Question 37. Where is nervous tissue located?
Answer: Nervous tissue is located in the brain, spinal cord, and nerves.
In simple words: It is found in the brain, spinal cord, and network of nerves.

Question 38. What are neurons?
Answer: Neurons are the structural and functional units of nervous tissue specialized for receiving and transmitting nerve impulses.
In simple words: Neurons are specialized nerve cells that carry electrical signals through the body.

Exam Tip: Define them as the functional units of nervous tissue.

Question 39. What is the chief function of columnar tissue in the digestive system?
Answer: The chief function of columnar epithelium in the digestive tract is absorption of digested nutrients and secretion of digestive juices and mucus.
In simple words: It absorbs digested food nutrients in the stomach and intestines.

Exam Tip: Mention absorption of nutrients and secretion.