ORGANISATION IN THE LIVING THINGS

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1 2 ORGANISATION IN THE LIVING THINGS I. Multiple choice questions: Tick ( ) the correct choice. 1. A group of similar cells which perform a particular function is called (a) organism (b) tissue (c) organelle (d) organs Ans. (b) 2. Two organ systems in plants are (a) roots and stem (b) root system and shoot system (c) stem and branches (d) all the above Ans. (b) 3. A level of organisation above the population is (a) organism (b) ecosystem (c) community (d) biosphere Ans. (c) 4. Biosphere consists of (a) atmosphere, lithosphere and hydrosphere (b) atmosphere and hydrosphere (c) ecosystem only (d) abiotic and biotic components 5. Biotic community consists of (a) only animals (b) all organisms (c) only plants (d) organisms and the environment Ans. (b) 6. Trachea is a part of (a) digestive system (b) excretory system (c) respiratory system (d) circulatory system Ans. (c) 7. Bones and cartilages are a part of (a) skeletal system (b) respiratory system (c) muscular system (d) excretory system Biology Class VII 1 Question Bank

2 8. Which of the following is a protective tissue? (a) Muscular tissue (b) Connective tissue (c) Epithelial tissue (d) Nervous tissue Ans. (c) 9. The tissue which forms the internal lining of organs is (a) nervous tissue (b) epithelial tissue (c) connective tissue (d) a muscle Ans. (b) 10. Nervous tissue consists of (a) nerve cells (b) tendons (c) cyton (d) lymph 11. Short branching structures arising from the cell body of a neuron are called (a) axons (b) cyton (c) dendrites (d) lymph Ans. (c) 12. The muscles which take part in breathing movements are (a) involuntary muscles (b) cardiac muscles (c) voluntary muscles (d) all the above 13. Muscles found in heart are (a) voluntary muscles (b) cardiac muscles (c) involuntary muscles (d) all the above Ans. (b) 14. Tissues found in growing regions are (a) meristematic tissues (b) complex tissues (c) simple tissues (d) permanent tissues 15. Meristematic tissues have (a) small, thin-walled cells rich in cytoplasm (b) small, thick-walled cells (c) dead cells (d) cells which can divide for a short period Biology Class VII 2 Question Bank

3 16. Vascular tissues in a plant are (a) xylem and phloem (b) xylem, phloem and epidermis (c) only xylem (d) only phloem 17. A group of living organisms which can breed among themselves belong to the same (a) population (b) community (c) ecosystem (d) class 18. A biotic community consists of (a) only plants (b) only animals (c) plants and animals (d) plants, animals and micro-organisms Ans. (d) 19. The number of individual organisms of a particular species form a (a) population (b) community (c) ecosystem (d) biosphere 20. The cells of cartilage are present in fluid-filled spaces called (a) matrix (b) stroma (c) lacunae (d) vacuoles Ans. (c) 21. White fibrous tissue present in tendons joins (a) bone to a bone (b) bone to a muscle (c) muscle to a muscle (d) all the above Ans. (c) 22. Voluntary muscles are (a) cylindrical and branches (b) cylindrical and unbranched (c) spindle-shaped (d) spherical Ans. (b) 23. Meristematic tissues have (a) continuously dividing cells (b) dead cells (c) cells which divide for a short period (d) cells which do not divide at all Biology Class VII 3 Question Bank

4 II. 24. Which of the following tissues do not possess living protoplasm at maturity? (a) collenchyma (b) sclerenchyma (c) tracheids (d) xylem parenchyma Ans. (c) 25. Xylem consists of (a) vessels, sieve tubes, fibres and xylem parenchyma (b) vessels, phloem parenchyma, fibres and companion cells (c) vessels, tracheids, fibres and xylem parenchyma (d) vessels, sieve tubes, fibres and phloem parenchyma Ans. (c) 26. Ovary is a/an (a) organ (b) system (c) organism (d) tissue 27. Simple epithelial tissue is (a) closely packed, unilayered (b) loose and vascular (c) made of fibres (d) none of the above 28. Axon and dendrites are the parts of (a) neuron (b) reproductive cell (c) xylem (d) none of the above Fill in the blanks. 1. A group of cells that are similar in size and shape and do the same job is called Different tissues that work together form An organ used to get rid of the wastes in our body is In plants, the organ that makes food is the Individuals of the same kind of organisms form a About two-third of the body weight is made up of... tissue. 7. Bone is a type of... tissue. Biology Class VII 4 Question Bank

5 8.... muscles are found in the walls of stomach and intestine. 9. Cells are living, elongated and thickened at the corners in... tissue. 10. Water moves upward inside the plant body through... tissue. 11. Movement of food material in the plant body takes place through... tissue. 12. Permanent tissues arise from... tissues. 13. Cells of... a tissue bring about increase in plant length. 14. The cells of... a tissue constantly undergo cell-division. 15. The skin is made up of... tissue. 16. The sensory message is carried by the... tissue. 17. The liquid part of blood is defend our body against germs tissue is made of cells without any intercellular spaces muscles help in the movement of limbs. 21. A long cylindrical process arising from the cyton is called tissue joins bones to muscles is a fluid connective tissue without red blood cells tissue is situated at the tip of root and stem tissue can contract to move parts of the body. Ans. 1. tissue 2. Organ 3. kidney 4. Leaves 5. Population 6. Connective 7. Connective 8. Involuntary 9. Collenchyma 10. Xylem 11. Phloem 12. Meristematic 13. Meristematic 14. Meristematic 15. Epithelial 16. Nervous 17. Blood Plasma 18. While Bood cells 19. Epithelial 20. Voluntary 21. Axon 22. Tendon 23. Lymph 24. Apical Meristematic tissue 25. Muscular. Biology Class VII 5 Question Bank

6 III. Which of the following statements are true (T) and which ones are false (F)? Mark T or F. 1. The stomach is a tissue. 2. Different cells that join up and work together are called organs. 3. Tissues alone cannot do same jobs in the body. 4. Tissues, organs and organ systems are made of cells. 5. Different organ systems help each other. 6. All members of a population compete for similar resources. 7. Complexity goes on increasing as we move from lower levels to higher levels of organistion. 8. Meristematic cells are small and thin-walled. 9. Permanent tissue is an immature tissue. 10. Stomata are present in the ground tissue of the leaf. 11. Xylem tissue is made of sieve tubes. 12. Epithelial tissue is a protective tissue. 13. Muscular tissues show the property of contraction and expansion. 14. Cyton and axon are the parts of a nerve cell. 15. The fluid part of the blood is called plasma. 16. Sclerenchyma consists of thick-walled dead cells. 17. Phloem is a complex tissue. 18. Cardiac muscles have light and dark bands. 19. Voluntary muscles are present in the internal organs of the body. 20. Yellow fibrous tissue, a type of connective tissue, is found in ligaments. 21. The fluid-filled spaces in which cartilage cells are present, are called lacunae. 22. Tendons connect bone to muscles. 23. Unicellular animals lack cell differentiation. 24. A group of cells similar in structure and function form an organ. Biology Class VII 6 Question Bank

7 25. The animal tissues and the plant tissues are similar in structure and function. Ans. 1. F 2. F 3. T 4. T 5. T 6. T 7. T 8. T 9. F 10. F 11. F 12. T 13. T 14. T 15. T 16. T 17. T 18. T 19. F 20. T 21. T 22. T 23. T 24. F 25. F. IV. Find the odd one out, giving reasons: 1. Cyton, dendrite, plasma, axon Ans. Plasma Reason: All are the parts of nerve cell except plasma that is the part of blood. 2. Bone, epithelium, tendon, cartilage Ans. Epithelium Reason: All are the parts of connective tissue except epithelium which is the part of epithelial tissue. 3. Xylem, collenchyma, parenchyma, sclerenchyma Ans. Xylem Reason: All are simple permanent tissue except xylem which is complex permanent tissue. 4. Vessels, companion cells, sieve tubes, collenchyma. Ans. Collenchyma Reason: Collenchyma is simple permanent tissue while others are the parts of complex permanent tissues. 5. lymph, white fibrous tissue, yellow fibrous tissue, areolar tissue Ans. Lymph Reason: Lymph is fluid connective tissue while others are proper connective tissue. 6. parenchyma, collenchyma, vascular bundle, sclerenchyma Ans. Vascular bundle Reason: All are simple permanent tissues except vascular bundle. 7. tendon, squamous epithelium, ligament, bone Ans. Squamous epithelium Biology Class VII 7 Question Bank

8 Reason: All are connective tissues except squamous epithelium which is epithelial tissue. 8. thrombocytes, erythrocytes, lacunae, leucocytes Ans. Lacunae Reason: All are fluid connective tissue except lacunae. V. In the items of Column I with the items of Column II. Column I Column II 1. Sieve Tube (a) Phloem 2. Trachieds (b) Fibres 3. Tendon (c) neuron 4. Blood (d) connects bone to bone 5. Phloem (e) found in leaf stalks 6. cartilage (f) fluid connective tissue 7. Ligament (g) connects muscles to bone 8. Xylem (h) has no blood vessels or nerves 9. Collenchyma (i) conducts food from leaves downwards 10. Nerve tissue (j) Conducts water from roots Ans. 1. a 2. b 3. g 4. f 5. i 6. h 7. d 8. j 9. e 10. c. VI. Differentiate between the following: 1. Organism and Population Ans. Organism Population (1) It is lower level of (1) It is higher level of organisation. organisation. (2) The organ systems collec- (2) All the organisms of single tively form an organism. species in a given area constitute a population. (3) Cell is the smallest unit of (3) Organism is the smallest organism unit of population. Biology Class VII 8 Question Bank

9 2. Population and Community Ans. Population Community (1) All the individuals of a (1) The populations of single species in a given different species in an area area constitute population. constitute a community. (2) It is next higher level of (2) It is next higher level of organisation above the organisation above the individual level. population level. (3) Population is made of only (3) Community is made of single species many species. 3. Ecosystem and Biosphere Ans. Ecosystem Biosphere (1) It is higher level of organi- (1) It is highest level of organisation above community. sation above ecosystem. (2) Biotic and abiotic commu- (2) The part of Earth that nities constitute ecosystem. support life constitute biosphere. (3) Ecosystem consists of (3) Biosphere consists of autotrophs, heterotrophs hydrosphere, lithosphere, and decomposers. and atmosphere. 4. Tissues and Organs Ans. Tissue Organs (1) It is lower level of organi- (1) It is also lower level of sation above cell. organisation above tissue. (2) A group of similar cells (2) Some tissues combine that work together to do the and form organ. same job is called tissue. (3) In a tissue, all the cells do (3) In an organ, all the tissues the same job. do not do the same job, e.g. Epithelial tissue, e.g. Liver, Kidney. connective tissue. Biology Class VII 9 Question Bank

10 5. Skeletal muscle tissue and Cardiac muscle tissue. Ans. Skeletal muscle tissue Cardiac muscle tissue (1) These muscles are attached (1) These muscles are present to skeleton. in the wall of heart. (2) These muscles are elongated, (2) These muscles are branched cylindrical and possess elongated cylindrical, transverse bands. and fused with one another. (3) These are voluntary muscles (3) These are specific type of i.e. can move by the will. involuntary muscles and can not move by the will. 6. Meristematic tissue and Permanent tissue Ans. Meristematic tissue Permanent tissue (1) The cells of meristematic (1) The cells of permanent tissue have the ability of tissue have no ability of division. division. (2) These tissues are present (2) These tissues are present at the tip of root and stem. in the non-growing part of root and stem. (3) The cells of meristematic (3) The cells of permanent tissue are small, thin-walled tissue are thin walled with with no inter-cellular space. much less amount of cytoplasm. (4) Meristematic tissue give rise (4) Permanent tissue are to permanent tissue. derived from meristematic tissues. 7. Simple and Complex tissues Ans. Simple tissue Complex tissue (1) Simple tissue consists of (1) Complex tissue consists of only one type of cells, i.e. more than one type of cells. structurally and functionally similar. Biology Class VII 10 Question Bank

11 (2) Simple tissue is of three (2) Complex tissue is of two types Parenchyma, types xylem, phloem. Collenchyma, Sclerenchyma. (3) Simple tissue provides (3) Complex tissues forms the mechanical strength to the way for the transportation plant and also store food in of water and food. some plants. 8. Bone and Cartilage Ans. Bone Cartilage (1) It is made of ground sub- (1) It is made of ground substance called matrix which is stance called matrix which filled with various inorganic contains cartilage cells. salts like calcium phosphate, calcium carbonate. (2) Bones are hard due to (2) Cartilage is highly elastic. presence of calcium. (3) A long bone has a hollow (3) Cartilage is not supplied cavity filled with bone with blood vessels. marrow which is supplied with blood vessels. 9. Voluntary and Involuntary muscles Ans. Voluntary muscles Involuntary muscles (1) Movement is under the will (1) Movement is not under the of the animal. will of the animal. (2) All the muscles are attached (2) Present in the organs like to skeleton and get tired alimentary canal, urinary and when over-worked. do not get tired. (3) They are cylindrical and not (3) They are spindle-shaped. branched. (4) They are multinucleated. (4) They are uninucleated. Biology Class VII 11 Question Bank

12 10. Xylem and Phloem Ans. Xylem Phloem (1) It is water-conducting (1) It is food-conducting tissue. tissue. (2) It is composed of tracheids, (2) It is composed of sieve vessels, fibres and xylem cells, phloem fibres and parenchyma. phloem parenchyma. VII. Classify the following as cells, tissues, organs, organ systems or organisms: 1. Chlamydomonas 2. Leaf 3. Stomach 4. Stem 5. Shoot system 6. Skin 7. Amoeba 8. Blood 9. Flower 10. Bone Ans. Tissue: Blood, Bones. Organ: Stomach, Flower, Leaf, stem, skin. Organ system: Shoot system. Organism: Chlamydomonas, Amoeba. VIII. Name the main organs of the following systems: 1. Digestive system Ans. Main organs of digestive system: 1. Mouth 2. Oesophagous 3. stomach 4. Liver 5. Panereas 6. Small intestine 7. Large intestine 2. Respiratory system Ans. Main organs of respiratory system: 1. Nostril 2. Trachea 3. Bronchi 4. Lungs 3. Circulatory system Ans. Main organs of circulatory system: 1. Heart 2. Arteries 3. Veins 4. Capillaries 4. Nervous system Ans. Main organs of Nervous system: 1. Brain 2. Spinal cord 3. Nerves Biology Class VII 12 Question Bank

13 5. Excretory system Ans. Main organs of Excretory system: 1. Kidney 2. Lungs 3. Skin 6. Skeletal system Ans. Main organs of skeletal system: 1. Bones. IX. See the figures shown below. Identify these figures giving reasons. These thin-walled cells are parenchyma. (b) These thick-walled cells at corner are collenchyma. (c) These thick-walled, long cell are sclerenchyma. (d) These tubular structures are xylem. X. Name the tissue found in the following: 1. At the tips of root and stem Ans. Apical meristematic tissue. 2. On the surface of roots Ans. Dermal tissues. 3. Lining of stomach Ans. Epithelial tissues. 4. Wall of heart Ans. Cardiac muscle tissue 5. Blood Ans. Connective tissues. Biology Class VII 13 Question Bank

14 XI. Complete the table stating any one location in the body and the function of each of the following tissues: Tissue Location Function 1. Ciliated epithelium 2. Fibrous tissue 3. Glandular tissue 4. Cardiac tissue 5. Nervous tissue Ans. Tissue Location Function 1. Ciliated epithelium Inner side of Remove dust particles. respiratory passage. 2. Fibrous tissue Tendon & ligament Insulation of body. 3. Glandular tissue Endocrine glands Secretion 4. Cardiac tissue Heart wall Pumping of blood 5. Nervous tissue Brain Reflex action. XII. Rearrange the following levels of organisation in their correct sequence: 1. Organism, Cell, organ, Tissue, Organ system. Ans. Cell Tissue Organ Organ system Cell organism 2. Ecosystem, Organism, Community, Ecosphere, Population. Ans. Organism Population Community Ecosystem Ecosphere XIII. Name: 1. The tissue that covers and protects the organs in animals. Ans. Epithelial tissue. 2. The type of muscle tissue found in the heart. Ans. Cardiac muscles Biology Class VII 14 Question Bank

15 3. The soft tissue of plants. Ans. Parenchyma 4. The tissue whose cells have a very thick cell wall. Ans. Sclerenchyma 5. The tissue that stores fat. Ans. Adipose 6. The tissue that joins bones together. Ans. Ligament 7. The liquid connective tissue. Ans. Blood XIV. Name: 1. two major plant tissues Ans. 1. Meristematic tissue 2. Permanent issue. 2. four major animal tissues Ans. 1. Epithelial tissue 2. Muscular tissue 3. Nervous tissue 4. Connective tissue 3. Three types of areolar connective tissues Ans. 1. Tendon 2. Ligament 3. Adipose 4. Three types of muscle cells Ans. 1. Striated muscles 2. Smooth muscles 3. Cardiac muscles. XV. Give the function of: (i) epithelium (ii) endothelium (iii) neuron (iv) muscles (v) xylem Ans. (i) Epithelium Protects the organs from outside. (ii) Endothelium. Protects the organs from inside. (iii) Neuron. Responsible for various sensory perceptions. (iv) Muscles. Responsible for the movement in animals. (v) Xylem. Responsible for upword water conduction. XVI. The connective tissues are of many types depending upon the type of matrix they have. How many types of connective tissues are found in animals? Biology Class VII 15 Question Bank

16 Ans. Connective tissues are of three types: (a) Areolar connective tissue (b) Supporting connective tissue (c) Fluid connective tissue XVII. Give reasons: (i) Muscle cells are called muscle fibres. Ans. Muscle cells in a muscular tissue are thin, long and fibre-like. So, these cells are called muscle fibres. These cells have the properties of contraction and relaxation. Due to these properties, body movements occur. (ii) Bone is connective tissue. Ans. Bones are connective tissue because they connect the various tissues and organs in the body. (iii) The stem of a herb is soft and perenchymatous; yet, it is firm and rigid. Ans. Parenchyma is a soft simple tissue and it provides temporary support to the plant. (iv) Xylem is a complex tissue. Ans. Xylem is a complex tissue because it is made of more than one type of cells. (v) Phloem is a conducting tissue. Ans. Phloem is a conducting tissue because food manufactured by green leaves is transported to roots and other parts of plants through phloem. (vi) Smooth muscles are involuntary muscles. Ans. Smooth muscles are involuntary muscles because these muscles are present in the organs which are not under the will of the animal, e.g. muscles of alimentary canal. Biology Class VII 16 Question Bank

17 XVIII. The organs of various systems are listed in the first column of the chart. Put a tick in any of the other columns if the organ belongs to any of the systems. Note: An organ may belong to more than one system. Organs System Digestive Respiratory Excretory Reproductive Circulatory Nervous Skeletal 1. Vertebrae 2. Large intestine 3. Bladder 4. Brain 5. Nose 6. Pancreas 7. Liver 8. Kidneys 9. Spinal cord 10. Lungs 11. Heart 12. Ureter 13. Mouth 14. Nerves 15. Wind pipe 16. Food pipe 17. Bone 18. Cartilage XIX. Answer the following questions: 1. What is meant by higher levels of organisation Ans. Higher levels of organisation: There are some organisations which are above the level of organism. These are as follows: (a) Population (b) Community (c) Ecosystem (d) Biosphere (a) Population. We have a number of plants and animals Biology Class VII 17 Question Bank

18 around us. Each member of plants and animals belongs to a particular species. A species is a group of living organism which can breed among themselves. All the members of this species in a particular area constitute its population. For example: human beings living in a particular area represent a population of Homo sapiens. Similarly, a number of dogs in a specific area forms the population of dogs. (b) Community. We see populations of plants and animals around us. Thus, the populations of different species occurring in a locality together forms a plant-animal community or biotic community. In this community, we have producers (green plants); the primary consumers or herbivores; and carnivores and decomposers like bacteria and fungi. (c) Ecosystem. In a community, we have various living things. These living things interact with the non-living things of the environment and form an ecosystem. Thus, an ecosystem consists of biotic and abiotic components. Ecosystems are natural or man-made, e.g., pond ecosystem, garden ecosystem. (d) Biosphere. It is the highest level of organisation in hierarchy. It is the part of the earth which support life in air, water and soil. It is the zone on Earth in which all living beings exist. 2. Arrange the following in an increasing order of their organisation. Also, complete the missing links in the hierarchy. Cell, Organ, Community, Population, Biosphere Ans. Cell Tissue Organ Organ system Community Population Organism Ecosystem Biosphere. Biology Class VII 18 Question Bank

19 3. Mention the different levels of organisation in a multicellular organism. Ans. Cell Tissue Organ Organ system Community Population Organism Ecosystem Biosphere 4. Explain the relationship between cells, tissues and organs. Ans. A tissue is a group of similarly specialised cells which together do the same job. An organ is made of different kinds of tissues and performs a specific function. Cells Tissues Organ 5. Give the functions of each of the following systems: (a) Digestive system (b) Respiratory system (c) Circulatory system (d) Nervous system (e) Excretory system (f) Skeletal system Describe the structure and functions of different types of animal tissues. Digestive system. Function. The main function of digestive system is to convert complex food into simple and soluble form. By this way, it can be absorbed by the blood and produce energy. (b) Respiratory system. Function. The main function of respiratory system is to exchange oxygen and carbon dioxide that produce energy. (c) Circulatory system. Function. It provides body cells with food and oxygen and also collects CO 2 and other metabolic waste products. (d) Nervous system. It is the principal means of Biology Class VII 19 Question Bank

20 communication between body parts and controls the body parts. (e) Excretory system. Function. It is to get rid of metabolic wastes from the body. (f) Skeletal system. Function. It provides frame work to the body and produce movement with the help of muscles. 6. How is connective tissue different from other tissues? Ans. Connective tissues are different from other tissues because they are characterised by cells that produce and maintain a wide variety of extracellular material around themselves. It is extracellular matrix that determines the physiological and physico-chemical properties of connective tissues. 7. Mention the main characteristics of meristematic tissues. Ans. Meristematic tissues have the ability of cell division. So, these tissues are present at the growing regions, i.e., the tip of stem and root. They also contribute tip of stem and root. They also contribute in thickness due to lateral meristem. The cells of meristematic tissues have following characteristics: (i) The cells are small and thin-walled. (ii) The cells are rich in cytoplasm with prominent nuclei. (iii) The cells lack inter-cellular space and divide activity and increase the growth. 8. Where to we find the meristematic tissue in plants? Ans. Meristematic tissues have the ability to divide. So, these tissues are present in the growing regions, i.e., the tip of stems and roots. These tissues are also present laterally so, they also contribute in thickness. 9. What is the function of meristematic tissues? Ans. The function of meristematic tissues is to contribute towards growth in length and width of the plant. Biology Class VII 20 Question Bank

21 10. Name the different types of plant tissues. Ans. Plant tissues: In plants, two types of tissues are present: (1) Meristematic tissues (2) Permanent tissues. Permanent tissues can be classified in two ways Based on their origin (1) Dermal tissue (2) Vascular tissue (3) Ground or fundamental tissue. Based on the kind of cells. (1) Simple tissues: It is of following types: (a) Parenchyma (b) Collenchyma (c) Sclerenchyma (2) Complex tissues: It is of following types: (a) Xylem (b) Phloem. 11. Where are stomata present in a plant cell? Ans. Stomata are present in the dermal tissue, particularly in the lower epidermis. 12. What is the function of stomata? Ans. Function of stomata: Stomata are specialised pores found mainly in the epidermis on the upperside of the leaf. Gases moves into and out of the leaf through stomata. 13. Name the tissue which takes part in the movement of water and minerals in the body. Ans. Movement of water and minerals in the plant body occurs through a complex permanent tissue called xylem. 14. What is a tissue? Ans. Tissue is a group or layer of cells that are alike and work together to perform a specific function. 15. What is the difference between an organ and an organ system? Ans. Organ. An organ is made of many tissues which work in a cooperative and co-ordiante manner, to perform a specific function, e.g. the lung, the kidney are some organs of animals. Organ system. When some organs concerned with one specific process then it collectively called on organ system. For example: Nose, Trachea, bronchi and lungs collectively form an organ system called respiratory system. Biology Class VII 21 Question Bank

22 16. Explain the structure and functions of epithelial tissue. Ans. Epithelial tissue. It is a protective tissue that covers the external surface of the body in the forms of skin and lines the internal organs. The cells of epithelial tissue are very close to each other without intercellular space. On the basis of the shape of the cells, these tissues is classified into three types: (i) Squamous epithelium. These cells are hexagonal or irregular in shape by surface view. This epithelium lines the blood vessels and oesophagus and forms the epidermis of the skin. It provides protection and prevents the entry of microorganisms. (ii) Columnar epithelium. The shape of cells are column-like, i.e., height is more then width. Nucleus is present at the base of cell. It lines the stomach, intestine, pharynx and larynx. (iii) Cuboidal epithelium. The cells are cube-shaped i.e., length and width are almost equal. Nucleus is situated at the centre of the cell. This epithelium is present in the thyroid gland kidney tubules etc. 17. What are involuntary muscles? Ans. Involuntary muscles. The muscles which are not under the control or will of animals are called involuntary muscles. Internal organs of human body like alimentary canal are not under the control of will. So, these organs are made of involuntary muscles. 18. How can you make your cardiac muscles work harder? Ans. Our cardiac muscles work hard because out heart muscles works continuously and never get tired. A healthy heart does not run out of oxygen either. Oxygen comes to the heart directly through arteries on its outside surface. 19. Which tissue is responsible for the increase in the height of a plant? Where is it located? Biology Class VII 22 Question Bank

23 Ans. Meristematic tissue is responsible for the increase in the height of a plant. This tissue is located at the tip of roots and stems. 20. What are the differences between parenchyma, collenchyma and sclerenchyma tissues? Ans. Difference between parenchyma, collenchyma and sclerenchyma Parenchyma Collenchyma Sclerenchyma (1) The cells may be oval, (1) The cells are either circular, (1) They are also somewhat spherical or cylindrical- oval or spherical. spherical. shaped. (2) It is made up of thin- (2) It is made up of cells (2) It is made up of cells walled cells. thickened at the corner. thickened all over. (3) It is made of living cells- (3) It is also made of living (3) It is made of dead cells without intercellular space. cells and intercellular with no protoplasmic space generally absent. content. (4) The function of parenchyma (4) This tissue gives strength (4) They also give mechanicells is to store food. to the parts in which it is cal strength to the stem. present. 21. What are the various types of cells present in xylem? What are their functions? Ans. Xylem. It is complex permanent tissue. It is composed of tracheids, vessels, fibres and xylem parenchyma. Tracheids are usually long and narrow cells which taper at both the ends. Vessels are the series of cells which form tube-like structure. In tracheids and vessels, living protoplasm is absent at maturity. Fibres provide strength to the tissue. Xylem parenchyma is the only living component and help in the conduction of water and to store food. 22. What do you understand by the term organisation? Ans. The term organisation may be defined as the manner in which small units of any structures or system are arranged into larger ones and the larger ones into still larger ones in hierarchy where the units of each level coordinate with one another towards a particular goal. Biology Class VII 23 Question Bank

24 23. Give one difference between biological and ecological hierarchy. Ans. Biological hierarchy is lower level of organisation, i.e. it starts from cell and end at organism. Ecological hierarchy is higher level of organisation, i.e. it starts from populations and end at Biosphere. Cells Tissue Organs Organ system Organism Lower level organisation or Biological hierarchy Organism Population Community Ecosystem Biosphere 24. Is cardiac muscle involuntary or voluntary? Ans. Cardiac muscles are special types of involuntary muscles. 25. Bring out one point of difference between: (a) Bone and cartilage (b) Meristematic and permanent tissue. Unlike other connective tissue cartilage does not contain blood vessels. Thus, compared to other connective tissues, cartilage grows and repairs more slowly. (b) Meristematic tissues have the ability of cell division while permanent tissues have no ability of cell division. 26. How do skin and kidney maintain waste balance in the human body? Ans. In our body, extra water is to remove out with the help of kidneys and skin. Kidneys extract metabolic wastes from the blood and excrete them in the form of urine. The skin removes water and salts through the sweat glands in the form of sweat. Higher level organisation or Ecological hierarchy Biology Class VII 24 Question Bank

25 27. Give one point of difference between community and ecosystem. Ans. Community is the group of living organism in a specific area while ecosystem is formed of the communities by the interaction with non-living things. 28. Write the names of organ system following is part of (a) Kidney (b) Liver (c) Xylem (d) Ovaries (e) Stomach (f) Trachea (g) Heart (h) Uterus Kideny Excretory system (b) Liver Digestive system (c) Xylem Water-conducting system (d) Ovaries Reproductive system (e) Stomach Digestive system (f) Trachea Respiratory system (g) Heart Circulatory system (h) Uterus Reproductive system **** Biology Class VII 25 Question Bank