Tissue Class 9 Science Chapter 6 Extra Questions

Class 9 Science Chapter 6 Extra Questions are available here. These extra questions are prepared by the subject experts.

Tissue Class 9 Science Chapter 6 Extra Questions

Question 1: What distinguishes unicellular organisms from multicellular organisms in terms of cellular functions?

Answer: Unicellular organisms rely on a single cell to perform all basic functions such as movement, intake of food, gaseous exchange, and excretion. In contrast, multicellular organisms have millions of cells, with most cells specialized to carry out specific functions.

Question 2: How do multicellular organisms demonstrate division of labour among cells?

Answer: Multicellular organisms exhibit division of labour by grouping specialized cells together to perform specific functions efficiently. For example, in humans, muscle cells contract for movement, nerve cells transmit messages, and blood transports oxygen, food, hormones, and waste.

Question 3: What is a tissue in multicellular organisms?

Answer: A tissue is a cluster of cells that are similar in structure and function, organized to achieve maximum efficiency in performing a specific function. Blood, phloem, and muscle are examples of tissues in multicellular organisms.

Question 4: How do plants and animals differ in terms of structure and movement?

Answer: Plants are stationary and have a large quantity of supportive tissue to remain upright, often consisting of dead cells. In contrast, animals move around in search of food, mates, and shelter, consuming more energy compared to plants.

Question 5: What is a key difference in the type of tissues between plants and animals?

Answer: Plants predominantly have supportive tissues with dead cells, while animals mostly possess tissues composed of living cells.

Question 6: Do plants and animals perform similar functions despite their structural differences?

Answer: No, plants and animals do not perform similar functions. Plants, being stationary, focus on support and nutrient transport within their structures. Animals, being mobile, prioritize activities such as hunting, mating, and shelter-seeking, requiring more energy and active tissue function.

Question 7: How does growth differ between plants and animals?

Answer: Growth in plants is limited to specific regions where certain tissues continuously divide throughout their life. This results in the classification of plant tissues into growing (meristematic) and permanent tissues. In contrast, cell growth in animals is more uniform, without distinct regions of dividing and non-dividing tissues.

Question 8: What are meristematic tissues in plants?

Answer: Meristematic tissues in plants refer to regions where cell division occurs continuously throughout the plant’s life, enabling growth and development.

Question 9: Why is there no demarcation of dividing and non-dividing regions in animals?

Answer: In animals, cell growth tends to be more uniform throughout their bodies, without specialized regions where cell division is restricted or concentrated.

Question 10: How does the structural organization of organs and organ systems differ between complex animals and plants?

Answer: Complex animals exhibit a more specialized and localized structural organization of organs and organ systems compared to even very complex plants. This difference reflects their distinct modes of life, particularly in feeding methods and adaptation for sedentary (plants) versus active locomotion (animals).

Question 11: What contributes to the differences in organ system design between plants and animals?

Answer: Plants are adapted for a sedentary existence, requiring specialized structures for support and nutrient absorption. Animals, with their active locomotion, have organ systems specialized for movement, hunting, and other active behaviors.

Question 12: How does the concept of tissues relate to complex animal and plant bodies?

Answer: The concept of tissues becomes significant in understanding the specialized structural and functional organization within complex animal and plant bodies, highlighting how cells organize into tissues to perform specific functions efficiently.

Question 13: Where does growth occur in plants, and why is it limited to certain regions?

Answer: Growth in plants occurs only in specific regions where meristematic tissue, responsible for cell division, is located. This tissue is restricted to these points, known as meristems.

Question 14: What are the types of meristematic tissues based on their location?

Answer: Meristematic tissues in plants are classified into apical (at the tips of roots and shoots), lateral (in the cambium layers of stems and roots), and intercalary (at the base of leaves and internodes) based on their location within the plant.

Question 15: How do cells produced by meristem change as they mature?

Answer: Initially, cells produced by meristem are similar to the meristem cells themselves. However, as these cells grow and mature, their characteristics gradually change, and they differentiate into components of other tissues within the plant.

Question 16: What is the function of apical meristem in plants?

Answer: Apical meristem is located at the growing tips of stems and roots, responsible for increasing the length of the stem and root.

Question 17: How does lateral meristem (cambium) contribute to plant growth?

Answer: Lateral meristem, found in the cambium layer, increases the girth or thickness of the stem or root.

Question 18: Why do cells of meristematic tissue lack vacuoles?

Answer: Cells of meristematic tissue lack vacuoles because vacuoles typically store water, nutrients, and waste products, which might hinder the high metabolic activity and rapid cell division required in meristematic cells.

Question 19: What are a few layers beneath the epidermis generally composed of?
Answer: Generally simple permanent tissue.

Question 20: What is the most common type of simple permanent tissue?
Answer: Parenchyma.

Question 21: How are parenchyma cells characterized?
Answer: They consist of relatively unspecialised cells with thin cell walls, and they are living cells.

Question 22: What is the typical arrangement of cells in parenchyma tissue?
Answer: They are usually loosely arranged, with large intercellular spaces.

Question 23: What is the primary function of parenchyma tissue?
Answer: It generally stores food.

Question 24: What is parenchyma called when it contains chlorophyll and performs photosynthesis?
Answer: Chlorenchyma.

Question 25: What is the function of large air cavities in parenchyma in aquatic plants?
Answer: They help the plants float.

Question 26: What is parenchyma with large air cavities called?
Answer: Aerenchyma.

Question 27: What permanent tissue provides flexibility in plants and allows bending without breaking?
Answer: Collenchyma.

Question 28: Where can collenchyma tissue be found in plants?
Answer: In leaf stalks below the epidermis.

Question 29: What are the characteristics of collenchyma cells?
Answer: They are living, elongated, and irregularly thickened at the corners with very little intercellular space.

Question 30: What additional function does collenchyma provide besides flexibility?
Answer: It provides mechanical support.

Question 31: What is the type of permanent tissue that makes the plant hard and stiff?
Answer: Sclerenchyma.

Question 32: What is an example of a plant part made of sclerenchymatous tissue?
Answer: The husk of a coconut.

Question 33: What are the characteristics of sclerenchyma cells?
Answer: The cells are dead, long, and narrow with thickened walls due to lignin, often having no internal space inside the cell.

Question 34: Where is sclerenchyma tissue present in plants?
Answer: In stems, around vascular bundles, in the veins of leaves, and in the hard covering of seeds and nuts.

Question 35: What function does sclerenchyma tissue provide to plant parts?
Answer: It provides strength to the plant parts.

Question 36: What is the outermost layer of cells in a plant called?
Answer: Epidermis.

Question 37: How is the epidermis usually structured?
Answer: It is usually made of a single layer of cells.

Question 38: Why might the epidermis be thicker in some plants?
Answer: In plants living in very dry habitats, the epidermis may be thicker to protect against water loss.

Question 39: What does the epidermis cover in a plant?
Answer: The entire surface of the plant.

Question 40: What is the function of the waxy, water-resistant layer secreted by epidermal cells on the aerial parts of the plant?
Answer: It aids in protection against loss of water, mechanical injury, and invasion by parasitic fungi.

Question 41: How are the cells of the epidermal tissue arranged and why?
Answer: They form a continuous layer without intercellular spaces to play a protective role.

Question 42: What is the shape and wall structure of most epidermal cells?
Answer: Most epidermal cells are relatively flat, with outer and side walls often thicker than the inner wall.

Question 43: What are the small pores in the epidermis of the leaf called?
Answer: Stomata.

Question 44: What cells enclose the stomata?
Answer: Two kidney-shaped cells called guard cells.

Question 45: What are the functions of stomata?
Answer: They are necessary for exchanging gases with the atmosphere and for transpiration (loss of water in the form of water vapour).

Question 46: What feature do epidermal cells of the roots commonly have?
Answer: They commonly bear long hair-like parts that greatly increase the total absorptive surface area for water absorption.

Question 47: Why might the epidermis of some plants, like desert plants, have a thick waxy coating of cutin?
Answer: To provide a waterproof quality to help retain water in dry environments.

Question 48: What happens to the outer protective tissue of plants as they grow older?
Answer: It undergoes certain changes.

Question 49: What forms the layers of cells that constitute the cork?
Answer: A strip of secondary meristem located in the cortex.

Question 50: What are the characteristics of cork cells?
Answer: Cork cells are dead, compactly arranged without intercellular spaces, and have suberin in their walls.

Question 51: What is the function of suberin in the walls of cork cells?
Answer: Suberin makes the cork cells impervious to gases and water.

Question 52: What are simple permanent tissues?
Answer: Tissues made of one type of cells that look like each other.

Question 53: What is another type of permanent tissue besides simple permanent tissue?
Answer: Complex tissue.

Question 54: What characterizes complex tissues?
Answer: They are made of more than one type of cells that coordinate to perform a common function.

Question 55: What are examples of complex tissues?
Answer: Xylem and phloem.

Question 56: What function do xylem and phloem perform?
Answer: They are conducting tissues and constitute a vascular bundle.

Question 57: Why is vascular tissue important for complex plants?
Answer: It is a distinctive feature that has made possible their survival in the terrestrial environment.

Question 58: What components make up the xylem?
Answer: Tracheids, vessels, xylem parenchyma, and xylem fibres.

Question 59: What are the characteristics of tracheids and vessels in the xylem?
Answer: They have thick walls, and many are dead cells when mature. They are tubular structures.

Question 60: What is the function of tracheids and vessels in the xylem?
Answer: They transport water and minerals vertically.

Question 61: What is the function of xylem parenchyma?
Answer: The parenchyma stores food.

Question 62: What is the main function of xylem fibres?
Answer: They are mainly supportive in function.

Question 63: What components make up the phloem?
Answer: Sieve cells, sieve tubes, companion cells, phloem fibres, and phloem parenchyma.

Question 64: What are the characteristics of sieve tubes?
Answer: Sieve tubes are tubular cells with perforated walls.

Question 65: What is the function of phloem?
Answer: Phloem transports food from leaves to other parts of the plant.

Question 66: Which phloem cells are living?
Answer: All phloem cells except phloem fibres are living cells.

Question 67: What body movement can we feel when we breathe?
Answer: The movement of our chest.

Question 68: What specialized cells are responsible for the movement of body parts?
Answer: Muscle cells.

Question 69: How do muscle cells facilitate movement?
Answer: The contraction and relaxation of muscle cells result in movement.

Question 70: What happens to the oxygen we inhale during breathing?
Answer: It is absorbed in the lungs and then transported to all the body cells through blood.

Question 71: Why do cells need oxygen?
Answer: The functions of mitochondria, which require oxygen for energy production, provide a clue to this question.

Question 72: What substances does blood carry to all cells?
Answer: Blood carries oxygen and food to all cells.

Question 73: What does blood collect from all parts of the body?
Answer: Blood collects wastes from all parts of the body.

Question 74: Where are the collected wastes carried for disposal?
Answer: The collected wastes are carried to the liver and kidney for disposal.

Question 75: What are blood and muscles examples of?
Answer: They are examples of tissues found in our body.

Question 76: On what basis can we think of different types of animal tissues?
Answer: On the basis of the functions they perform.

Question 77: What are the different types of animal tissues mentioned?
Answer: Epithelial tissue, connective tissue, muscular tissue, and nervous tissue.

Question 78: What type of tissue is blood?
Answer: Blood is a type of connective tissue.

Question 79: What type of tissue do muscles form?
Answer: Muscles form muscular tissue.

Question 80: What are the covering or protective tissues in the animal body called?
Answer: Epithelial tissues.

Question 81: What does epithelium cover?
Answer: Epithelium covers most organs and cavities within the body and forms a barrier to keep different body systems separate.

Question 82: What are some examples of body parts made of epithelial tissue?
Answer: The skin, the lining of the mouth, the lining of blood vessels, lung alveoli, and kidney tubules.

Question 83: How are epithelial tissue cells arranged?
Answer: Epithelial tissue cells are tightly packed and form a continuous sheet with only a small amount of cementing material between them and almost no intercellular spaces.

Question 84: What must anything entering or leaving the body cross?
Answer: Anything entering or leaving the body must cross at least one layer of epithelium.

Question 85: What role does the permeability of epithelial cells play?
Answer: The permeability of epithelial cells plays an important role in regulating the exchange of materials between the body and the external environment and between different parts of the body.

Question 86: What usually separates all types of epithelium from the underlying tissue?
Answer: An extracellular fibrous basement membrane.

Question 87: How do different epithelia show differing structures?
Answer: They correlate with their unique functions.

Question 88: What is an example of a simple flat epithelium and where is it found?
Answer: Simple squamous epithelium, found in cells lining blood vessels or lung alveoli.

Question 89: How are simple squamous epithelial cells described?
Answer: They are extremely thin and flat, forming a delicate lining.

Question 90: Where else is squamous epithelium found besides blood vessels and lung alveoli?
Answer: It is found in the oesophagus, lining of the mouth, and the skin.

Question 91: How is the epithelium of the skin structured, and why?
Answer: Skin epithelial cells are arranged in many layers to prevent wear and tear, making it stratified squamous epithelium.

Question 92: Where are tall epithelial cells present and what is their function?
Answer: Tall epithelial cells are present where absorption and secretion occur, such as in the inner lining of the intestine. They facilitate movement across the epithelial barrier.

Question 93: What is columnar epithelium?
Answer: Columnar epithelium is epithelial tissue that is tall and pillar-like in shape.

Question 94: What additional feature does columnar epithelial tissue in the respiratory tract have?
Answer 3: It has cilia, which are hair-like projections on the outer surfaces of epithelial cells.

Question 95: What is the function of cilia in the respiratory tract epithelium?
Answer 4: The movement of cilia pushes mucus forward to clear it.

Question 96: What is the specific term for epithelium with cilia in the respiratory tract?
Answer 5: It is called ciliated columnar epithelium.

Question 97: Where does cuboidal epithelium form the lining?
Answer 1: Cuboidal epithelium forms the lining of kidney tubules and ducts of salivary glands.

Question 98: What is the shape of cells in cuboidal epithelium?
Answer 2: Cube-shaped cells.

Question 99: What function does cuboidal epithelium provide in kidney tubules and salivary glands?
Answer 3: It provides mechanical support.

Question 100: How do epithelial cells acquire additional specialization?
Answer 4: Epithelial cells can acquire additional specialization as gland cells, which can secrete substances at the epithelial surface.

Question 101: How is glandular epithelium formed?
Answer 5: Sometimes a portion of the epithelial tissue folds inward, forming a multicellular glandular structure.

Question 102: What type of tissue is blood categorized as?
Answer: Blood is categorized as a type of connective tissue.

Question 103: Why is blood called ‘connective’ tissue?
Answer: It is called connective tissue because it connects different parts of the body and transports substances between them.

Question 104: How are the cells of connective tissue arranged?
Answer: The cells of connective tissue are loosely spaced and embedded in an intercellular matrix.

Question 105: What is the nature of the matrix in connective tissue?
Answer: The matrix may be jelly-like, fluid, dense, or rigid, depending on the function of the particular connective tissue.

Question 106: What is the fluid matrix of blood called?
Answer: Plasma.

Question 107: What components are suspended in the plasma?
Answer: Red blood corpuscles (RBCs), white blood corpuscles (WBCs), and platelets.

Question 108: What substances does plasma contain?
Answer: Plasma contains proteins, salts, and hormones.

Question 109: What is the function of blood in the body?
Answer: Blood flows and transports gases, digested food, hormones, and waste materials to different parts of the body.

Question 110: What is bone classified as?
Answer: Bone is classified as a connective tissue.

Question 111: What functions does bone serve in the body?
Answer: Bone forms the framework that supports the body, anchors muscles, and supports the main organs of the body.

Question 112: What are the properties of bone tissue?
Answer: Bone tissue is strong and nonflexible.

Question 113: What advantage do these properties provide for bone functions?
Answer: The strength and nonflexibility of bone tissue provide support and protection to the body’s structure and organs.

Question 114: What is the matrix of bone composed of?
Answer: The matrix of bone is composed of calcium and phosphorus compounds.

Question 115: What type of connective tissue connects two bones to each other?
Answer: Ligament.

Question 116: How would you describe the characteristics of ligaments?
Answer: Ligaments are very elastic and have considerable strength. They contain very little matrix.

Question 117: What is the function of ligaments?
Answer: Ligaments connect bones with bones.

Question 118: What connects muscles to bones in the body?
Answer: Tendons.

Question 119: How are tendons described in terms of their properties?
Answer: Tendons are fibrous tissue with great strength but limited flexibility.

Question 120: What type of connective tissue is cartilage?
Answer: Cartilage is another type of connective tissue.

Question 121: How are the cells in cartilage arranged?
Answer: Cartilage has widely spaced cells.

Question 122: What is the matrix of cartilage composed of?
Answer: The solid matrix of cartilage is composed of proteins and sugars.

Question 123: Where is cartilage found in the body?
Answer: Cartilage is found in joints to smoothen bone surfaces, as well as in the nose, ear, trachea, and larynx.

Question 124: How are cartilage and bone different in terms of flexibility?
Answer: Cartilage can be folded (as seen in the ears), while bones in the arms cannot be bent, highlighting the difference in their flexibility and structure.

Question 125: Where is areolar connective tissue found in the body?
Answer: Areolar connective tissue is found between the skin and muscles, around blood vessels and nerves, in the bone marrow, and it fills the space inside organs.

Question 126: What functions does areolar connective tissue perform?
Answer: It supports internal organs and helps in the repair of tissues.

Question 127: Where is fat-storing adipose tissue found in our body?
Answer: Adipose tissue is found below the skin and between internal organs.

Question 128: What fills the cells of adipose tissue?
Answer: The cells of adipose tissue are filled with fat globules.

Question 129: Besides storing fats, what additional function does adipose tissue perform?
Answer: Adipose tissue acts as an insulator.

Question 130: What does muscular tissue consist of?
Answer: Muscular tissue consists of elongated cells, also known as muscle fibres.

Question 131: What is the function of muscular tissue?
Answer: Muscular tissue is responsible for movement in our body.

Question 132: What special proteins do muscles contain?
Answer: Muscles contain contractile proteins, which contract and relax to cause movement.

Question 133: What are involuntary movements controlled by?
Answer: Involuntary movements, like the movement of food in the alimentary canal or the contraction and relaxation of blood vessels, are controlled by smooth muscles.

Question 134: Where are smooth muscles found in the body?
Answer: Smooth muscles are found in the iris of the eye, in ureters, and in the bronchi of the lungs.

Question 135: How would you describe the shape and nucleus of smooth muscle cells?
Answer: Smooth muscle cells are long with pointed ends (spindle-shaped) and uninucleate (having a single nucleus).

Question 136: Why are smooth muscles also called unstriated muscles?
Answer: Smooth muscles are called unstriated muscles because they do not show the striations (alternate light and dark bands) seen in skeletal muscles under the microscope.

Question 137: What is the specialized function of nervous tissue cells?
Answer: Nervous tissue cells are highly specialized for responding to stimuli and transmitting them rapidly within the body.

Question 138: What parts of the body are composed of nervous tissue?
Answer: The brain, spinal cord, and nerves are composed of nervous tissue.

Question 139: What are the cells of nervous tissue called?
Answer: The cells of nervous tissue are called nerve cells or neurons.

Question 140: What are the main components of a neuron?
Answer: A neuron consists of a cell body with a nucleus and cytoplasm, and it has a single long part called the axon, along with many short, branched parts called dendrites.

Question 141: How long can an individual nerve cell (neuron) be?
Answer: An individual nerve cell (neuron) may be up to a meter long.

Question 142: What makes up a nerve?
Answer: Many nerve fibres bound together by connective tissue make up a nerve.

Question 143: What is the signal called that passes along the nerve fibre?
Answer: The signal is called a nerve impulse.

Question 144: What does a nerve impulse allow us to do?
Answer: Nerve impulses allow us to move our muscles when we want to.

Question 145: Why is the functional combination of nerve and muscle tissue fundamental to most animals?
Answer: This combination enables animals to move rapidly in response to stimuli.