CBSE Class 9 Biology Tissues Worksheet Set D

1 Mark Questions

Question. Why is sometimes squamous epithelium called stratified squamous epithelium?
Answer. The squamous epithelium when gets arranged in form of layers then it is known as stratified squamous epithelium.

Question. What type of function is performed by a single cell of amoeba?
Answer. Amoeba being a unicellular organism performs all the vital functions like respiration, metabolism, and other functions like ingestion of food, excretion.

Question. What is the function of guard cell in the stomata?
Answer. The guard cell controls the opening and closing of the stomata which helps in exchange of gases and water vapour in the atmosphere.

Question. What is the function of root hairs?
Answer. The hair like projections present on the roots helps in the increased absorption of water through soil by increasing the surface area for absorption.

Question. Name the branch of biology which deals with the study of tissues.
Answer. Histology

Question. Tissue which forms lining of the mouth is?)
Answer. Squamous epithelium is a simple flat cells forming lining of the mouth.

Question. Name the outermost layer of cells in old plants.
Answer. Cork

Question. Water hyacinth floats on the water by maintaining buoyancy in water. What part of plant body is responsible for this?
Answer. In aquatic plants, there are large cavities present in parenchyma which help these plants to float above the water by maintaining its buoyancy.

Question. A chemical responsible for the stiffness of husk of the coconut. Also name the plant tissue found in the husk.
Answer. Lignin, a chemical substances which gets deposited on the wall of the cell making it stiff. The plant tissue of which husk is made is known as Sclerenchyma tissue.

Question. What is tissue?
Answer. A group of cell performing similar function combines to form a tissue. On a broad basis tissues are divided into two: Animal Tissue and Plant tissue.

Question. Which tissue is commonly known as packing tissue in animals?
Answer. Areolar tissue

2 Mark Questions

Question. A person got wounded, his blood is flowing continuously out of the wound, and blood clot is not formed. Which component of the blood is missing in the blood of the person?
Answer. Blood platelets which are essential for clotting of blood at the site of injury is absent or less in no. In the person’s blood which can cause serious loss of blood from the body and ultimately death.

Question. State the function of
Answer. (a) Aerenchyma
(b) Chlorenchyma
(a) Aerenchyma- Provides buoyancy to aquatic plants as contains large air cavities.
(b) Chlorenchyma – Does Photosynthesis as contains chloroplasts.

Question. How is involuntary action different from voluntary action? Quote an example.
Answer. Voluntary action: the action which is under our will. It is attained with the help of skeletal muscles. Example: movement of the limbs Involuntary action: the action which is not under our will. It is attained with the help of smooth and cardiac muscles. Example: movement in alimentary canal

Question. Why heart is not made of smooth muscles.
Answer. Since heart pump need to regularly pump blood all over the body it needs to work fast. This is not achieved by smooth muscle and so cardiac muscle makes heart to contract and relax.

Question. A Gardner was cutting the the excess plants growing in the garden by mistake he cuts the apical meristem of a plant. What will happen? Will there be any change in the growth of the plant?
Answer. Apical meristem is a type of meristematic tissue found on the tips of roots , shoots, leaves, etc. There basic function is to provide growth to the plant by growing roots and shoots from the tips. There by there would be no or less growth shown by the plant.

Question. Epidermis of plants living in arid regions is thicker than in the usual ones. give reason.
Answer. In hot and dry regions the chances of drying of plant is more as more water is lost through transpiration. to prevent this loss the outer covering of the plants i.e. epidermis is thicker than plants in other region.

Question. Write a short note on the functions of lymph.
Answer. It helps in transportation of nutrients like oxygen, glucose which could be filtered through blood capillaries. It also protects the body against infections.

Question. What are the functions of blood?
Answer. Blood carries oxygen and food to all the body cells and in return takes up the waste matter produced by the cell and carries it to liver and kidney. It carries nutrients, hormones and vitamins to the cells.

Question. Write ‘I’ for involuntary action and ‘v’ for voluntary actions for the following activities:
(a) Pumping of heart
(b) Movement of head
(c) Peristaltic movement
Answer. (a) I
(b) V
(c) I

Question. What are simple permanent tissues? Name its type.
Answer. These are the tissues formed from a single type of cells structurally and performing similar functions.
Types of simple permanent tissues are:
(a) Parenchyma
(b) Collenchyma
(c) Sclerenchyma

3 Mark Questions

Question. Quote the various functions of meristematic tissue?
Answer. – Acts as a parent tissue: Leads to development of other tissue from itself.
-Forms new cells: Sustain growth by forming news cells for the pre – existing ones.
-Continuous production of plant parts: Plant parts like leaves, branches stem, roots, fruits, etc are continuly formed.
– Easy healing of injured parts: Provides healing of injury by forming new cells.

Question. Write a short note on functions of collenchymas tissue.
Answer. Functions:
– Provides mechanical support to plants.
– Provides tensile strength to the plant provided with flexibility to bend its parts easily without breaking.
– Is the chief mechanical tissue for young plants Sclerenchyma

Question. Write some features of cork and where they have application.
Answer. Features:
– Dead cells with no intercellular spaces.
– Contains a chemical substance , suberin which restricts the penetration of gases and water through it.
– Protects plants from injuries, water loss and germs.
Applications
– Commercially used for making products like bottle stoppers, shuttle cork.

Question. Answer in one word.
1. Pigment which is helpful in performing photosynthesis.
2. Packing tissue of plant
3. Process of specialization of meristemetic tissue to a permanent shape, size and function.
4. Meristem present at growing tips of roots
5. Dead element in phloem
Answer. 1. Chlorophyll
2. Parenchyma
3. Differentiation
4. Apical meristem
5. Phloem fibre or bast fibre

Question. What is role of tissues present in multi-cellular organisms?
Answer. The formation of tissues is important in multi-cellular organisms as :
(a) Grouping of cells and performing a single function by the group shows division of labour.
(b) Tissues combine to form organ, organ to organ system and organ systems to organisms.
(c) Due to improved organisation and higher efficacy organisms have high survival rate.

Question. Write the characteristics of Meristematic tissues.
Answer. – Cells are spherical, oval , polygonal or rectangular in shape with thin cellulose cell walls.
– Intercellular spaces absent
– Dense cytoplasm
– Prominent nucleus
– Vacuoles absent

Question. Show the experiment used to study of the stem.
Answer. Procedure:
– Cut the stem into thin slices.
-Stain them with safranin
-Take thin nicely cut slice on the slide
Put a drop of glycerine on the slice and gently cover it with a cover slip. Observe the slice into microscope

Question. What are the types of tissues found in animals?
Answer. On the basis of functions the animal tissues are divided into the following:
– Muscular tissue
– Nervous tissue
– Connective tissue
– Epithelial tissue
– Muscular tissue

Question. What is the basic functions performed by epithelium tissue?
Answer. – protects the underlying organs from injuries, chemical effect and drying up.
– helps in absorption of water and nutrients.
– helps in elimination of waste products
– keeps different organs separate
– some have secretary functions, substances like saliva, mucus ,etc are secreted by some cells.

Question. ‘I can walk, eat or dance according to my will but cannot control functioning of heart and blinking of eyes. ‘ Comment.
Answer. The above actions are performed by muscles of one or other type. Actions can be divided into two Voluntary and involuntary actions which are performed by skeletal or striated muscles and smooth or involuntary muscles.
The actions like walking,eating,dancing which are under control of our will are voluntary actions whereas actions like contraction and relaxatiom of heart and blinking of eyes is not in ones own hand so is an involuntary action.

Question. Raj and Ajay were playing football with their friends, raj suddenly got injured. Ajay with other friends took him to hospital where doctor told them that raj got sprain in leg and should rest for some days. They took him home and regularly visited him to enquire about his situation.
Answer the following questions:
(a) What is sprain?
(b) Is this a serious issue?
(c) What values are shown by raj’s friends?
Answer. (a) At the time of sprain, the ligament , a type of connective tissue gets stressed out.
(b) No, this not a serious issue as with resting the stress of the ligament could be reduced in few days.
(c) Raj’s friends love raj and are very helpful in nature.

5 Mark Questions

Question. State the functions of the following.
Answer. (a) Epidermis
(b) Cork
(a) Epidermis provides protection to all body parts of plant as there structure does not have any intercellular spaces in between the cells. In dry places, epidermis forms a thick covering on the plant to protect the plant from drying due to transpiration. It also protects the plant towards mechanical injury and invasion from foreign organisms.
(b) Cork forms the bark of the tree and is protective in function like epidermis. The walls of cork cells are thickened by a chemical known as suberin. This chemical makes the cells impermeable to water and gases which prevents desiccation, infection and mechanical injury to plant.

Question. state the structure of the following:
(a) Vessels
(b) Tracheids
(c) Sieve tubes
Answer. (a) Vessels:
– Dead cells
Lignified cell walls
Pipe like structure with upper and lower portions absent in the tubes
(b) tracheids:
– Dead cells
long elongated cells with tapering ends
-non-lignified areas present known as pits through which water flows.
(c) Sieve tubes:
– cells are elongated with thin cell walls
– nucleus and other organelles absent
– cytoplasm is continuous due to presence of pores

Question. Show with a help of an experiment show apical meristem causes growth in length of plant.
Answer. Procedure:
1. Take two onions in jar filled with water such that the onions are slightly dipped in water.
2. After five days observe the growth of the roots.
3. Cut the tips of roots of onion placed in jar 2.
4. After few days observe the growth of roots in both the jars.
Observation:
1. Jar 1 shows root elongation
2. Jar 2 do not show further growth in the roots
Inference:
Since the tips of roots in jar 2 were cut therefore no growth was shown. Therefore the tissues present at the tips i.e. apical meristem is responsible for growth of the plant.

Question. A short note on Types of epidermis.
A) Aerial epidermis
B) Root epidermis
Answer. (A) Aerial epidermis is the epidermis making an outer covering of the aerial parts of plant. Epidermis sometimes secrete waxy substance called cutin which makes a water proof layer around the plant.
Function: Helps in preventing plants from desiccation and foreign invasion. Stomata are present on epidermal cells for exchange of gases with atmosphere and loss of water in atmosphere. In desert plants, the epidermis and cutin is thick preventing greater water loss from the plant surface.
(B) Root epidermis the epidermis present on the surface of root making its outer covering.
Function: This also helps in absorption of water. This epidermis has some hairy projection which increases water absorption by increasing the surface area for absorption.

Question. Which tissue gives flexibility in plants?

Answer: Collenchyma.

Question. Where is parenchyma tissue present?

Answer: Parenchyma tissue is present below the epidermis.

Question. What is the structure of a neuron?

Answer: Building block of a nervous tissue is a neuron. It has a thread-like structure with axon and cell body.

Question. Mention the types of simple and complex tissues.

Answer: Simple : (i) Sclerenchyma, (ii) Parenchyma,
(iii) Collenchyma
Complex : (i) Phloem (ii) Xylem

Question. Where can we find apical meristem?

Answer: It is found in the growing tips of roots and stem.The length of roots and stem is increased due to the presence of apical meristem.

Question. Name the tissue which is responsible for the movement of our body?

Answer: A combination of following two tissues is responsible for the movement of our body :
(i) Muscular tissue
(ii) Nervous tissue

Question. Which tissue is present in the husk of a coconut?

Answer: Sclerenchyma.

Question. What do you mean by aerenchyma?

Answer: Aerenchyma is the cell with large air-filled cavities of parenchyma. It helps aquatic plants to float.

Question. Name the two types of tissues.

Answer: (i) Animal tissues
(ii) Plant tissues

Question. What will happen if ligaments are over stretched?

Answer: Sprain will occur.

Question. What will happen if apical meristem is damaged?

Answer: Growth of plant in length will stop.

Question. Define differentiation.

Answer: The process of taking up permanent size, shape and function of cell is called differentiation.

Question. Why does the growth of plants occur only in certain specific regions?

Answer: Growth of plants occurs only in certain specific region because the meristematic tissue is located only at these points.

Question. Name the connective tissue that is found between skin and muscles.

Answer: Areolar connective tissue fills the space between skin and muscles.

Question. Name the tissues which are present in the plants at the nodes.

Answer: Intercalary tissues.

Question. What is basement membrane?

Answer: 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.What are areolar tissues’ junctions?
Answer. Areolar tissues are connective tissue found in animals. We can find them between skin and muscles, around blood vessels and nerves, in bone marrow. These tissues fill the space inside the organs. They support internal organs and help to repair tissues.

QuestionWhat are the four important types of tissues found in animal?
Answer. The four animal tissues are :
(i) Epithelial tissues,
(ii) Connective tissues,
(iii) Muscular tissues, and
(iv) Nervous tissue.

Question.What is the main function of vascular tissue in plants?
Answer. Vascular tissue transport :
(i) Water and dissolved minerals from roots to various parts of the plant (xylem).
(ii) Prepare food material from leaves to different plant parts (phloem).

Question.Why do meristematic cells lack vacuoles?
Answer. Meristematic cells divide frequently to give rise to new cells. So, they need dense cytoplasm and soft cell wall.Vacuoles cause hindrance in cell division as they are full to cell sap and provide turgidity and rigidity to the cell.

Question.What is epithelial tissue?
Answer. Epithelial tissue : Epithelial tissue forms covering of entire surface of the body and lines the internal organs, because of this epithelial tissue is called protective tissue. It also forms a barrier to keep different body system separate. In this tissue, cells are closely associated and arranged on a very thin extracellular fibrous basement membrane. Epithelial tissue may be composed of one (simple epithelium) or more layers of cells (compound epithelium).

Question.What are muscular tissue? What is their function?
Answer. This is a specialised tissue which is composed of contractile, fibre-like cell. This tissue is responsible for movement in our body.
Function : The movement of the body or limbs is brought about by contraction and relaxation of contractile proteins present in muscle cells.

Question.What are the three types of muscle fibres (muscle cells)?
Answer. These are three types of muscle fibres :
1. Striated muscle (skeletal muscle or voluntary muscle),
2. Unstriated muscle (smooth muscle or involuntary muscle),
3. Cardiac muscle.

Question.What are protective tissues?
Answer. All parts of plants, e.g. leaves, flowers, stem, and root are covered by a single outermost protective layer called epidermis. It consists of rectangular, closely fitted relatively flat cells which lack intercellular spaces. Usually it is one cell thick and is covered with cutin. Epidermis protects internal tissues of the plant.
In old dicot plants, epidermis is replaced by secondary meristem which cuts cells toward outerside. Cork cells do not have intercellular spaces and are dead cells.
The walls of cork cells are heavily thickened due to the position of suberin. Presence of suberin makes the cells impervious to gases and water and thus prevents evaporation of water.

Question.Explain how the bark of a tree is formed. How does it act as a protective tissue?
Answer. As trees grow old, a strip of secondary meristem replaces the epidermis of the stem. Cell on the outside are cut off this layer. This forms the several layer thick cork or the bark of the tree.Bark is a mass of dead tissue lying in the peripheral region of the plant body as a hard dry covering. Its function is protection. It protects the inner tissues against the attack of fungi and insects, against loss of water by evaporation, etc.

Question.What is a cardiac muscle? Mention its features too.
Answer. Cardiac muscle is an extremely specialized tissue developed to pump blood throughout the body.
Features :
(i) Cylindrical in shape
(ii) Branched and single celled
(iii) Striated muscle fibres
(iv) Involuntary in nature

Question.Complete the sentences.
(i) _____ conducts minerals and water.
(ii) _____ conducts food in higher plants.
(iii) Blood is a _____ type of tissue.
(iv) Bone has _____ cells.
(v) Cartilage has _____ cells.
(vi) The connective tissue where fibres are not present is _____.
Answer.
(i) Xylem
(ii) Phloem
(iii) connective
(iv) osteocyte
(v) chondrocyte
(vi) blood

Question.Name the following tissues.
(i) Which tissue covers the external surface in animals?
(ii) Which tissue stores fat in animals?
(iii) Which tissue joins bone to bone?
(iv) Which tissue divides and re-divides and responsible for growth in plants?
Answer.
(i) Epithelial tissue
(ii) Adipose tissue
(iii) Ligament
(iv) Meristematic tissue

Question.Write the characteristics of collenchyma.
Answer. The cells in this type of tissue are living, elongated and thickened with cellulose at the corners. There is very little intercellular space. This tissue provides flexibility and mechanical support to plants. This tissue is found in hypodermis of stems and leaf stalks.

Question.Describe the structure of sclerenchyma. Write its major functions.
Answer. Sclerenchyma is the chief mechanical tissue of plants.The cells of this tissue are usually long, narrow and pointed at both ends. Due to deposition of lignin their walls are often very highly thickened hence the lumen or cell cavity is nearly obliterated. They are usually provided with simple pits which may be oblique or straight. It provides strength to the plant parts.

Question.Describe the structure of phloem.
Answer. 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.Describe the structure of cartilage and bone.
Answer. 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.

Question.What are the two main components of blood? Why is blood considered a type of connective tissue?
Answer.
(i) Blood has two main components :
(a) Fluid (liquid) matrix called plasma.
(b) Suspended red blood cells (RBCs), white blood cells (WBCs) and platelets.
(ii) Blood is considered as connective tissue because :
(a) It has the same origin as the other connective tissues.
(b) It flows to different parts of the body and thus connects different parts of the body with one another to exchange materials and gases.

Question.What is xylem? Explain its structure. Which one of its component is very important and why?
Answer. 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.What are three main categories of connective tissue?
Answer. 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.Explain the structure of a fluid connective tissue.
Ans : Blood is a fluid connective tissue. Blood consists of :
1. Blood plasma, 2. Blood cells.
1. Blood plasma : It is the fluid matrix which contains 85 to 95% water, 7% different types of proteins,0.9% of salts, about 0.1% glucose and a very small amount of hormones, wastes, etc. In the plasma,blood corpuscles (cells) are suspended.
2. Blood cells : Three kinds of blood cells are found suspended in the blood plasma.
These are : (i) Red blood corpuscles (Erythrocytes) or RBCs (ii) White blood corpuscles (leucocytes or WBCs and (iii) Blood platelets.
(i) Red blood corpuscles (Erythrocytes) or RBCs : The red blood corpuscles are biconcave, disc-like cells which are devoid of nucleus.
They contain a substance called haemoglobin because of this they appear red in colour. The most important function of the RBCs is the transport of oxygen and carbon dioxide.
(ii) White blood corpuscles (Leucocytes) or WBCs : These cells are comparatively large in size, colourless and irregular in appearance.
They are devoid of haemoglobin. They protect our body from diseases by destroying germs.
(iii) Blood platelets : These are small, 2-4 m in diameter. They are without nucleus. Their main function is to liberate some substances which helps in blood clotting.

Question.Give one function of each of the following :
(a) Stomata, (b) Root nodules, (c) Cardiac muscle fibres.
Answer.
(a) Exchange of gases in plants.
(b) Root nodules are found in leguminous plants. They harbour bacteria which can fix free atmospheric nitrogen into nitrates and nitrites which plants like pulses can use for protein synthesis.
(c) Cardiac muscles show rhythmic contraction and relaxation throughout life. Because of this heart can pump the blood.