CBSE Class 10 Science Chapter 6 Life Processes Important Questions 2024-25 PDF

Important Questions for Class 10 Science Chapter 6 – Life Processes Very Short Answer Questions 1 Mark 1. Amoeba shows following kind of nutrition – (a) autotrophic (b)...

Important Questions for Class 10 Science Chapter 6 – Life Processes Very Short Answer Questions 1 Mark 1. Amoeba shows following kind of nutrition – (a) autotrophic (b) holozoick (c) saprotrophic (d) parasitic Ans: The nutrition shown by Amoeba is (b) holozoic. 2. The process by which blood is cleared of metabolic wastes in case of kidney failure is called a) artificial kidney b) dialysis c) transplantation d) filtration Ans: The process by which blood is cleared of metabolic wastes in case of kidney failure is called b) dialysis. Class X Science www.vedantu.com 1 3. Woody plants carry gaseous exchange through a) root hair b) stem hair c) lenticels d) epidermal cells Ans: Woody plants carry gaseous exchange through (c) Lenticels. 4. Where does digestion of starch begin in human body? Ans: The digestion of starch begins in human body in the mouth. 5. Give one example each of saprophytic and parasitic nutrition. Ans: One example each of saprophytic and parasitic nutrition are as follows: Parasitic Nutrition – Plasmodium (Protozoa) Saprophytic Nutrition – fungi. 6. Which of the following statements about the autographs is incorrect? a) They store carbohydrates in the form of starch. b) They constitute the first trophy level in food chains. c) They convert CO 2 and water into carbohydrates in the absence of sunlight d) They synthesize carbohydrates from CO 2 and water in the presence of Class X Science www.vedantu.com 2  sunlight & chlorophyll. Ans: c) They convert CO 2 and water into carbohydrates in the absence of sunlight. 7. Which of these is not a part of the small intestine? a) Duodenum b) Jejunum c) Ileum d) Rectum Ans: d) Rectum is not a part of the small intestine. 8. During contraction of heart, what prevents backflow of blood? a) Thin walls of atria b) Thick muscular walls of ventricles c) Valves in heart d) All of the above Ans: During contraction of heart, c) Valves inheart prevents backflow of blood. 9. Name excretory organ in amoeba and earthworm. Ans: The excretory organ in amoeba and earthworm are as follows: Amoeba – Cell membrane, Earthworm – Outer covering (skin) Class X Science www.vedantu.com 3 10. Name the plant tissue through which water and minerals are transported in plants. Ans: The plant tissue through which water and minerals are transported in plants is Xylem. 11. Trachea do not collapse when there is not much air because they are – a) thick and muscular b) having cartilaginous rings c) have valves d) supported by larynx. Ans: Trachea do not collapse when there is not much air because they are b) having cartilaginous rings. 12. Which one of the following blood vessels contains only deoxygenated blood? a) pulmonary vein b) pulmonary artery c) capillaries d) aorta Ans: b) Pulmonary artery one of the following blood vessels contains only deoxygenated blood. Class X Science www.vedantu.com 4 13. The autotrophic mode of nutrition requires – a) Chlorophyll b) Sunlight c) Carbon – dioxide & water d) All of the above Ans: The autotrophic mode of nutrition requires d) all of the above, that is, chlorophyll, sunlight and carbon-dioxide & water. 14. Name the red pigment carrying oxygen in blood. Ans: The red pigment carrying oxygen in blood Haemoglobin. 15. Name the hormone which is responsible for reabsorption of water in nephrons. Ans: The hormone which is responsible for reabsorption of water in nephrons Anti – diuretic – hormone (ADH) or vasopressin. 16. When air is blown from mouth into a test tube containing lime water, the lime water turned milky due to presence of – a) oxygen b) nitrogen c) water vapours d) carbon – dioxide Class X Science www.vedantu.com 5 Ans: When air is blown from mouth into a test tube containing lime water, the lime water turned milky due to presence of d) carbon – dioxide 17. In which of the following group/ groups of animals, heart does not pump oxygenated blood to different parts of the body? a) Pisces only b) Amphibians only c) Amphibians and Reptiles only d) Pisces and Amphibia Ans: The following group/ groups of animals, in which the heart does not pump oxygenated blood to different parts of the body a) Pisces only. 18. The filtration units of kidneys are called – a) Ureter b) Urethra c) Neurons d) Nephrons. Ans: The filtration units of kidneys are called d) nephrons. 19. What is the mode of nutrition in fungi and plasmodium? Ans: The mode of nutrition in fungi and plasmodium are as following: Class X Science www.vedantu.com 6 Fungi – Saprophytic Plasmodium – parasitic. 20. Which of them contain less nitrogenous waste – renal vein or the renal artery? Ans: Renal veins contain less nitrogenous waste. 21. Amoeba captures food with the help of – a) teeth b) cilia c) pseudopodia d) tentacles Ans: Amoeba captures food with the help of c) pseudopodia. 22. Which of the following is most appropriate for aerobic respiration? a) Glucose  mitochondria pyruvate  cytoplasm CO2 +H2O+Energy b) Glucose  cytoplasm pyruvate  mitochondria CO2 +H2O+Energy c) Glucose  cytoplasm pyruvate+Energy  mitochondria CO2 +H2O d) Glucose  cytoplasm pyruvate+Energy  mitochondria CO2 +H2O+Energy Ans: The most appropriate for aerobic respiration is (b) Class X Science www.vedantu.com 7 Glu cose  cytoplasm pyruvate  mitochondria CO2  H 2O  Energy. 23. Name the part of the alimentary canal that receives bile from the liver. a) Oesophagus b) Stomach c) Small intestine d) Large intestine Ans: The part of the alimentary canal that receives bile from the liver c) Small Intestine. 24. What is glycolysis? Ans: Breakdown of Glucose into pyruvate is known as glycolysis. 25. Name the largest artery of the body. Ans: The largest artery of the body is Aorta. 26. The kidneys in human beings are parts of the system for (a) nutrition (b) respiration (c) excretion Class X Science www.vedantu.com 8 (d) transpiration Ans: The kidneys in human beings are parts of the system for (c) excretion. 27. The xylem in plants are responsible for (a) transport of water (b) transport of food (c) transport of amino acids (d) transport of oxygen Ans: The xylem in plants are responsible for (a) transport of water. 28. The autotrophic mode of nutrition requires (a) carbon dioxide and water (b) chlorophyll (c) sunlight (d) all of the above Ans: The autotrophic mode of nutrition requires (d) all of the above. 29. The breakdown of pyruvate to give carbon dioxide, water and energy takes place in (a) Cytoplasm Class X Science www.vedantu.com 9 (b) mitochondria (c) chloroplast (d) nucleus Ans: The breakdown of pyruvate to give carbon dioxide, water and energy takes place in (b) mitochondria 30. Food moves down the gut by peristalsis. Which region of the brain controls peristalsis. Ans: Food moves down the gut by peristalsis and the region of brain which controls peristalsis is Medulla of hind brain. 31. Name the pigment present in plants, which can absorb solar energy. Ans: The pigment present in plants, which can absorb solar energy is Chlorophyll. 32. Which of the four chambers of the human heart has the thickest muscular walls? Ans: Right ventricle has the thickest muscular walls. 33. Which part of the visible spectrum is absorbed by chlorophyll pigments? Ans: Blue and Red light is absorbed by chlorophyll pigments. Class X Science www.vedantu.com 10 34. Name the cartilaginous flap which closes the glottis to check the entry of food into it during swallowing. Ans: The cartilaginous flap which closes the glottis to check the entry of food into it during swallowing is Epiglottis. 35. Which equipment is used to facilitate breathing during serious breathing problems? Ans: The equipment that is used to facilitate breathing during serious breathing problems is Ventilator. 36. What do you mean by double circulation of blood? Ans: Double circulation of blood means that blood passes through the heart twice for each cycle of the body. Short Answer Questions 2 Marks 1. What is common for cuscuta, ticks and leeches? Ans: Cuscuta, ticks, and leeches all feed in a parasitic manner, harming their hosts in the process. 2. What advantage over an aquatic organism does a terrestrial organism have with regard to obtaining oxygen for respiration? Ans: Terrestrial organisms have evolved to be more efficient at absorbing oxygen from the air than watery organisms. – Class X Science www.vedantu.com 11 (i) Increased respiratory surface area. (ii) Very fine and delicate surface for easy exchange of oxygen and carbon – dioxide. (iii) Placement of respiratory surface within the body for protection. (iv) Mechanism for transporting air into and out of the respiratory surface, which absorbs oxygen. 3. Differentiate between single and double circulation found in vertebrates. Ans: The differences between single and double circulation found in vertebrates are: Single Circulation Double circulation In this, blood passes only once Blood passes only once through the through the heart in one complete heart in one complete cycle. cycle. Only deoxygenated blood flows via The blood in the heart is both the heart. oxygenated and deoxygenated. It is ineffective. It's more effective. 4. Name the substrates for the following enzymes. a) trypsin b) amylase c) pepsin d) lipase Class X Science www.vedantu.com 12 Ans: The substrates for the following enzymes are as shown below a) Protein b) Starch c) Protein d) Lipids 5. What are the two stages in photosynthesis? Ans: Two stages in photosynthesis are– a) Light reaction – Photolysis of water is the process of breaking down water molecules into hydrogen and oxygen using light energy. b) Dark reaction – Carbon dioxide ( CO 2 ) is fixed and converted into glucose, a simple carbohydrate. 6. What is the difference between arteries & veins? Ans: The differences between arteries & veins are: Arteries Veins It is responsible for transporting It transports blood to the heart. blood away from the heart. They have very thin walls. They have a sturdy wall around them. They have narrow lumen. They have a wide lumen. Pressure is high. Pressure is low. Class X Science www.vedantu.com 13  It carries oxygenated blood. It carries deoxygenated blood. 7. What is villi? What are its functions? Ans: Villi are projections in the small intestine's inner lining that resemble fingers. They enhance the surface area available for digested meal absorption in the small intestine. 8. What type of respiration takes place in human muscles during vigorous exercise and why? Ans: Anaerobic respiration occurs in human muscles during severe exercise. During exercise our energy requirement increases, so our striated muscles start respiring anaerobically in the lack of oxygen and produce ATP molecules. 9. How is opening and closing of stomata regulated? Ans: Guard cells control the closure and opening of the stomata. The stomata open when the guard cells enlarge or become turgid owing to water ingress. Because of the loss of water, the guard cells shrink and the stomata close. 10. State two vital functions of the kidney. Ans: Function of kidney are – 1) It keeps the body's water balance in check. 2) It regulates calcium levels in the blood to keep bones healthy. Class X Science www.vedantu.com 14 11. Differentiate between aerobic and anaerobic respiration. Ans: The differences between aerobic and anaerobic respiration are: Aerobic Respiration Anaerobic Respiration In the presence of oxygen, it occurs. It happens when oxygen isn't present. It can be found in the cytoplasm and It's found in the cytoplasm. mitochondria. Complete breakdown of glucose. Incomplete breakdown of glucose. End products are CO 2 and H 2O. End products are CO 2 and ethyl alcohol or lactic acid. 12. Meat is easier to digest as compared to grass. Why? Ans: Meat is easier to digest because our digestive juices contain enzymes that can break down meat, but our bodies cannot break down cellulose, which is a major component of grass. 13. Differentiate between transport of materials in xylem & phloem. Ans: The differences between transport of materials in xylem & phloem are: Xylem Phloem It transports water and minerals. It transports food materials. Only upwards transport of substances is Substances are transported in both possible. upward and downward directions. Class X Science www.vedantu.com 15 14. What is the role of glomerulus in the kidney? Ans: Glomerulus, like Bowman's Capsule, is a collection of capillaries found in the cup. It gets blood from the renal artery, which is responsible for transporting excretory wastes from the body to the kidney. It removes from the liver water, salts, glucose, urea, nitrogen-containing protein end products, and yellow bile components. 15. Why is it essential to match the blood groups of donors and receiver person before arranging transfusion of blood? Ans: Blood RBCs carry both antigen and antibody. If the blood is not matched before transfusion, the recipient's blood produces antibodies against the donor blood and destroys blood cells, resulting in a blood shortage and death. 16. Why is it necessary to separate oxygenated & deoxygenated blood in mammals & birds? Ans: The separation of oxygenated and deoxygenated blood allows the organism to receive adequate oxygen. This mechanism is beneficial to creatures who demand a lot of energy. Mammals and birds use oxygen to obtain energy in order to maintain a consistent body temperature. 17. Why are the walls of the trachea supported by cartilaginous rings? Ans: The trachea is held together by cartilaginous rings that keep it from collapsing even when there isn't much air in it. Class X Science www.vedantu.com 16 18. What are the raw materials for photosynthesis? Ans: Raw materials for photosynthesis are – a) Carbon – dioxide b) Water c) Chlorophyll and Sunlight 19. What is the role of diaphragm during inhalation and exhalation? Ans: During inhalation and exhalation, the diaphragm changes form, increasing and decreasing the capacity of the thoracic cavity. This causes air to enter and exit the lungs. 20. What is the advantage of four chambers of heart? Ans: A septum separates the right and left halves of the heart, preventing oxygenated and deoxygenated blood from mingling. This satisfies their constant need for energy to keep their body temperature steady. Their energy requirements are substantial, which are met effectively due to the non-mixing of oxygenated and deoxygenated blood. 21. Why is diffusion insufficient to meet the oxygen requirements of multicellular organisms like humans? Ans: As all cells in multicellular animals are not in direct contact with the environment, simple diffusion is insufficient to supply the needs of all body cells. Class X Science www.vedantu.com 17 22. What criteria do we use to decide whether something is alive? Ans: To be considered alive, all living organisms must have movement at the molecular level, as well as respiration and other life processes such as nutrition, respiration, transportation, and excretion. 23. What is the function of digestive enzymes? Ans: Enzymes break down food's different complicated components into simple, soluble components that can be easily absorbed. 24. How are the lungs designed in human beings to maximize the area for exchange of gases? Ans: Bronchioles end in alveoli, which are balloon-like structures in the lungs. Alveoli have a network of blood capillaries that increase the surface area available for gas exchange. 25. What is the role of saliva in the digestion of food? Ans: Salivary amylase is an enzyme found in the mouth that breaks down starch, a complicated molecule, into glucose. 26. While eating you are advised not to talk. Why are you advised to do so? Ans: We are urged to do so because food particles may enter the windpipe when eating, causing choking. Class X Science www.vedantu.com 18 27. We say that movement is a characteristic of living organisms but we always don’t see visible movements in plants. Comment. Ans: Plants do not always show obvious movement. It doesn't necessarily imply that they aren't living. In their bodies, molecular movements take place. 28. If a person is working on a treadmill in a gymnasium, will it affect his rate of breathing? How? Ans: Yes, it will have an impact on his breathing rate. To satisfy the increased demand for energy, the rate of breathing will increase in order to supply more oxygen. 29. If you compare your rate of breathing by feeling your chest movement with the number of times a fish opens and closes its mouth. Which will be higher and way? Ans: As the amount of dissolved oxygen in water is relatively low compared to the amount of oxygen in the air, the number of times a fish opens and closes its mouth will be higher. As a result, aquatic organisms breathe at a significantly higher rate than terrestrial organisms. 30. Mucus is not used for churning the food or digesting it. Then why is it secreted in the stomach? Ans: In order to protect the stomach's inner lining from being harmed by HCI, mucus is released. Excessive HCI secretion can harm the lining of the stomach and cause a peptic ulcer. Class X Science www.vedantu.com 19 31. In the process of Photosynthesis food A is prepared which gets converted into food B. What are A and B? Why is A converted to B? Ans: Glucose is food A, whereas starch is food B. As B is an insoluble carbohydrate, it is transformed to A. It is more compact, making it better for storage. 32. When we are asleep we are not performing any activity while our life processes are going on. Why? Ans: “The maintenance functions of living organisms must go on even when they are not doing anything particular.” That is why the life processes are going on even while we are asleep or not performing any activity. 33. What will be the outcome if a farmer floods his field everyday? Ans: The oxygen contained in the interspaces of the soil will be replaced by water, affecting plant respiration. 34. Name the respiratory organs of: (i) fish Ans: The respiratory organs of fish are gills. (ii) mosquito Ans: The respiratory organs of mosquitoes are Trachea (air tubes). Class X Science www.vedantu.com 20 (iii) earthworm. Ans: The respiratory organs of earthworms are moist skin. 35. Due to availability of less water, how does the plant cope with lack of water in desert conditions? Ans: To preserve moisture, they open their stomata at night and close them during the day. 36. After a vigorous exercise, you may experience cramps in your leg muscles. Why does this happen? Ans: Leg muscle cramps are produced by a sudden build-up of lactic acid in our muscles following strenuous exercise. 37. What will happen if carbon monoxide combines with hemoglobin? Ans: If haemoglobin binds firmly to carbon monoxide, oxygen will not be transported by blood, resulting in the organism's death. 38. Chloroplasts are called energy convertors. Explain. Ans: As chloroplasts catch solar energy and convert it to chemical energy, they are known as energy convertors. 39. Why is the rate of breathing much faster in aquatic organisms than those of terrestrial organisms? Class X Science www.vedantu.com 21 Ans: Aquatic species get their oxygen from dissolved oxygen in water. Water has a relatively low oxygen availability as compared to air. As a result, aquatic organisms must breathe more quickly than terrestrial organisms. 40. Why are glomeruli considered as dialysis bags? Ans: The glomeruli's major filtering function is selective filtration. Small molecules comprising glucose, salts, urea, and liquid senim are filtered. Etc. Proteins and other big molecules remain in the blood. As a result, the glomeruli of the kidneys serve as dialysis bags. 41. Autotrophs synthesize food for the living world. Justify this statement in one sentence only by interconnecting autotrophs and heterotrophs. Ans: The food producers are autotrophs, and all heterotrophs directly or indirectly consume the food produced by the autotrophs. 42. Veins and arteries carry blood. Which of these carry blood? a) Away from the heart? Ans: Arteries carry blood away from the heart. b) Back to the heart? Ans: Veins carry blood back to the heart. Class X Science www.vedantu.com 22 43. Which of the organs perform the following functions in humans? i. Absorption of food. Ans: Absorption of food takes place in the small intestine. ii. Absorption of water Ans: Large intestine 44. Name the areas in a woody stem through which respiratory exchange of gases take place. Ans: In a woody stem, the bark has lenticels for gaseous exchange. 45. Why doesn’t the lungs collapse even after forceful expiration? Ans: Even after forced expiration to maximum capacity, residual volume refers to the amount of air that remains in the lungs following forceful expiration. As a result, even after a strong expiration, the lungs do not collapse. 46. “If there were no algae there would be no fish in the sea”. Comment. Ans: Photosynthesis results in the production of O 2 by algae. The oxygen used by fish in the sea is used for breathing. There would have been no oxygen created if algae had not existed. As a result, fish may have died. Class X Science www.vedantu.com 23 47. Why is the process of diffusion insufficient to meet the oxygen requirement of human beings? Ans: For bigger multicellular creatures like humans, the diffusion method is insufficient to transport O 2 to all areas of the body. As a result, the respiratory pigment haemoglobin absorbs oxygen from the air and transports it throughout our bodies via blood. Short Answer Questions 3 Marks 1. What are the functions of lymph in our body? Ans: Functions of lymph are- a) It removes tissue fluid from the interstitial region and restores it to the bloodstream. b) Through tissue fluid, it gathers carbon dioxide, waste products, and metabolites from tissues. c) Lymph contains lymphocytes (WBCs), which aid in the body's immunity and fight against invading invaders. 2. How is haemoglobin associated with respiration explained? Ans: The respiratory pigment haemoglobin is responsible for transporting oxygen and carbon dioxide. Haemoglobin is a crimson pigment with a strong oxygen affinity. Oxyhemoglobin transports oxygen from the lungs to the cells of the body. Carbon dioxide is carried to the lungs by carbamino – haemoglobin from the bodily cells. Class X Science www.vedantu.com 24 3. What are the modes of excretion in plants? Ans: Modes of excretion in plants are – a) The plants get rid of excess water by transpiration. b) Plants' only primary gas excretory product in oxygen. Plants emit it into the environment by diffusion.Organic wastes of plants are stored within dead permanent tissues such as wood or within leaves or bark which are periodically removed. c) The plants also excrete some waste substances into the soil around them. d) Plant waste products are accumulated in cellular vacuoles in large quantities. 4. Give an experiment to prove the essentiality of light for photosynthesis. Ans: An experiment to prove the essentiality of light for photosynthesis is as shown below: a) Destarched the plant by leaving it in dart for 48 – 72 hours. b) Now place strips of black paper or metal foil over destarched leaves and expose them to light for several hours. 5. What is “translocation”? Why it is essential for plants. Ans: The term "translocation" refers to the movement of organic solutes within plants. It is required since all cells require sustenance to perform their essential tasks. It affects the storage organs of roots, fruits, seeds, and developing organs in both upward and downward directions. Class X Science www.vedantu.com 25 6. How respiration takes place in plants? Ans: There are three modes for the exchange of gases in plants – a) Some little plants can exchange gaseous matter by simply diffusing it throughout their entire surface. b) Stomata on the leaves and green stems of large flowering plants exchange gases. c) Exchange occurs in woody stems through fractures in the bark or lenticels. 7. How is transpiration pull responsible for upward movement of water? Ans: Transpiration is the process through which leaves lose water in the form of water vapours through stomata. Continuous transpiration causes a suction in the xylem elements' water column, which reaches the roots. This is known as transpiration pull. The water column of the plant is drawn up from the bottom to the top due to transpiration. 8. Discuss the major steps involved in the process of nutrition in human beings. Ans: Major steps involved in human nutrition are – a) Ingestion – Food is taken in through the mouth. Humans have a holozoic feeding mode. Solid particles are swallowed by them. b) Digestion – In the alimentary canal, mechanical and chemical processes are used to break down complex dietary materials into simpler ones. c) Absorption – The little finger-like projections, or villi, of the small intestine absorb digested food. d) Assimilation – Food is absorbed and transported to all cells via blood, Class X Science www.vedantu.com 26  where it is used for energy, growth, and development. e) Excretion – Food from the small intestine passes through to the big intestine, where it is ejected out by Anus. 9. Discuss the mode of nutrition in amoeba. Ans: The steps of Nutrition in amoeba are– a) Formation of pseudopodia – When an amoeba comes into contact with a food particle, it creates pseudopodia that encases the food particle. b) Ingestion – Ingestion occurs when the terminals of pseudopodia merge with one other, forming a food vacuole with a variable amount of food particles and water. c) Digestion – The vacuoles are encircled by lysosomes, which fuse with the vacuole and consume the food particles inside. d) Exocytosis – The food vacuole passes the soluble products of digestion into the appropriate cytoplasm. Exocytosis is the process through which the remaining undigested items are passed out of the body. 10. With the help of a labelled diagram, discuss the structure of the cross – section of leaf. Ans: Leaf has two parts: (i) Epidermis – The epidermis is the cell's outermost layer. Stomata are tiny pores that connect cells in the lower epidermis. (ii) Mesophyll – Mesophyll refers to the chloroplast-containing parenchyma cells. Palisade and spongy parenchyma are the two types. Class X Science www.vedantu.com 27 11. What do you mean by ‘lymph’? Mention its function. Ans: Lymph- Tissue fluid, or lymph, is the fluid that fills the gaps between the cells in the tissues. Functions of lymph: (i) It returns tissue fluid from the interstitial spaces into the blood. (ii) Lacteals, which are lymph capillaries found in intestinal villi, aid in fat absorption. (iii)Through tissue fluid, it gathers carbon dioxide, waste products, and metabolites from tissues. 12. How are lungs designed in human beings to maximize the area of exchange of gases Ans: Lungs have evolved various characteristics to allow for effective gas exchange. The modifications are as follows: a) Increased surface area b) Very fine and delicate surface for easy exchange of oxygen and carbon dioxide c) Mechanism for transporting air into and out of the respiratory surface, which absorbs oxygen. 13. Dark reactions of photosynthesis do not need light. Do plants undergo dark reactions at night? Ans: The term "dark reaction" does not refer to a reaction that occurs in the absence of light, such as at night. In fact, these reactions are independent of light energy and occur at the same time as light reactions. Class X Science www.vedantu.com 28 14. Differentiate inhalation and exhalation. Ans: The differences between inhalation and exhalation are: Inhalation Exhalation It is taking in of air from the It is expelling out of the air from the atmosphere lungs. Diaphragm contract & flattens. Diaphragm relaxes and becomes dome shaped. Ribs movement is forward & Ribs movement is downward & inward outward. Volume of thoracic cavity increases Volume of thoracic cavity decreases Pressure of thoracic cavity decreases Pressure of thoracic cavity increases 15. With the help of a diagram, show pulmonary circulation in man. Ans: With the help of diagram, pulmonary circulation in man can be represented as shown below: Class X Science www.vedantu.com 29 16. What are the functions of the human respiratory system? Ans: The functions of human respiratory system are: (i) The cellular respiration function requires gaseous exchange. (ii) The vocal cords produce sound. (iii)Abdominal compression assists with urination, face passing, and birthing. (iv) Laughing and sneezing to clean the respiratory surface on their own. 17. What is the role of skin, lungs and intestine in the process of excretion in man? Ans: The role of skin, lungs and intestine in the process of excretion in man are: Skin – Skin excrete excess salts and water in the form of sweat. Lungs – Exhalation causes carbon dioxide to be expelled from the lungs. Intestine – Intestine throw out undigested food in the form of faeces through anus. 18. Explain the structure of chloroplast. Ans: The structure of chloroplast can be explained using the diagram as shown below: Class X Science www.vedantu.com 30 19. Why and how does water enter continuously into the root xylem of plants? Ans: Water and minerals are transported to the plant body via xylem. Root hairs are hairs that grow on a plant's roots. The root hairs come into close touch with the water film that forms between soil particles. Diffusion allows water and minerals to penetrate the root hair. The water and minerals taken by the root hair from the soil move via the epidermis, root cortex, endodermis, and root xylem by osmosis from cell to cell. The plant's xylem vessels in the root are connected to the xylem vessels in the stem. As a result, dissolved mineral-containing water passes through the root xylem vessels and into the stem xylem vessels. The stem's xylem vessels branch out into the plant's leaves. As a result, the water and minerals supplied by the xylem vessels in the stem reach the leaves via the branched xylem vessels that enter each area of the leaf from the petiole. As a result, water and minerals from the earth reach the plants' leaves via the root and stem. The suction created by the evaporation of water molecules from the cells of a leaf pulls water from the xylem cells of roots. Transpiration is the loss of water from the aerial portions of plants in the form of vapour. 20. What is the role of following in human digestive system – a) mucous Ans: Mucus – It shields the stomach's inner life from HCl. b) Bicarbonate Ans: Bicarbonate – It alkalizes the acidic meal so that pancreatic enzymes may work on it. Class X Science www.vedantu.com 31 c) Trypsin Ans: Trypsin – It digest proteins into amino acids. 21. What are outside raw materials used for by an organism? Ans: The following are examples of external raw materials used by an organism: a. Food b. Water c. Oxygen 22. What processes would you consider essential for maintaining life? Ans: The processes essential for maintaining life are: a. Nutrition b. Respiration c. Transportation d. Excretion 23. What is the difference between autotrophic and heterotrophic nutrition? Ans: The difference between autotrophic and heterotrophic nutrition is: Autotrophic nutrition Heterotrophic nutrition Class X Science www.vedantu.com 32  The form of nutrition in which an The mode of nutrition in which an organism uses sunlight energy to organism is unable to produce food produce its own food from simple from simple inorganic components inorganic components such as such as carbon dioxide and water and carbon dioxide and water found in must rely on food from other species. the environment. All green plants. All non-green plants. 24. Where do plants get each of the raw materials required for photosynthesis? Ans: Plants do get each of the raw materials required for photosynthesis from: (a) Carbon dioxide from the atmosphere. (b) Light from Sun (c) Water from Soil (d) Chlorophyll from chloroplast of green plants. 25. What is the role of the acids in our stomach? Ans: HCl plays following role in our stomach: (a) Make the medium acidic to allow the pepsin enzyme to work. (b) Kills the harmful bacteria present in food (c) Prevents fermentation of food 26. How is small intestine designed to absorb digested Ans: The villi, which are finger-like projections on the inner lining of the small intestine, enhance the surface area available for absorption. The villi are densely packed with blood arteries that convey the absorbed food to all of the body's cells. Class X Science www.vedantu.com 33 It is used to obtain energy and to repair damaged tissues. 27. What advantage over an aquatic organism does a terrestrial organism have with regard to obtaining oxygen for respiration? Ans: In comparison to aquatic organisms, terrestrial organisms breathe at a slower rate. This is owing to the fact that there is less oxygen in water than there is in air, thus aquatic species breathe at a faster rate. 28. What are different ways in which glucose is oxidized to provide energy in various organisms? Ans: The pathways of break-down of glucose in various organisms are as below: 29. How is oxygen and carbon dioxide transported in human beings? Ans: In humans, the pigment haemoglobin is found in RBC and has a high affinity for oxygen. It absorbs oxygen from the air in the lungs and transports it to tissues that are oxygen-deficient. In blood plasma, some oxygen is carried in a dissolved condition. Because carbon dioxide is more soluble in water than oxygen, it is usually carried through human blood as a dissolved form. Class X Science www.vedantu.com 34 30. What are the components of the transport system in human beings? What are the functions of these components? Ans: The components of human transport system include: (a) Heart- receives and pumps the blood. (b) Arteries- carry oxygenated blood away from the heart to various orgAns: (c) Veins- Bring back blood to heart. (d) Capillaries- exchange of various materials and gases between blood and tissues. 31. Why is it necessary to separate oxygenated and deoxygenated blood in mammals and birds? Ans: The right and left sides of the heart are separated to prevent oxygenated and deoxygenated blood from mingling. This separation allows for a very effective oxygen supply to the organism. This is important in creatures with high energy needs, such as birds and mammals, that use energy to maintain their body temperature all of the time. 32. What are the components of the transport system in highly organized plants? Ans: The xylem and phloem transport systems are found in higher plants. Water and minerals are transported from the root to different parts of the plant via vessels and tracheids in xylems. Food is transported from leaves to storage organs and other sections of the plant by phloem, which is made up of sieve tubes and companion cells. Class X Science www.vedantu.com 35 33. How are water and minerals transported in plants? Ans: Plants transport water and minerals through xylem, which is made up of tracheids and vessels. Osmosis transports water and minerals received by root hairs to the xylem tissues of the root. Water travels from the root xylem to the stem xylem and then to the leaves. 34. How is food transported in plants? Ans: Plants carry food via phloem, which is made up of sieve tubes, sieve cells, and companion cells. Food is prepared in leaves and transferred to the phloem of the leaves in a soluble form. Food is actively transported to all other areas of the plant. 35. What are the methods used by plants to get rid of excretory products? Ans: The methods used by plants to get rid of excretory products are: (i) During respiration, plants produce carbon dioxide as a waste product, and photosynthesis produces oxygen as a waste product. (ii) Excess of water is removed through transpiration. (iii)Some waste products like gums and resins are stored in older xylem tissue. 36. How is the amount of urine produced regulated? Ans: The amount of urine produced is determined by the amount of excess water in the body and the amount of a water soluble waste to be expelled. When the amount of water and dissolved wastes in a boy is high, the amount of urine generated is high, and when the amount of wastes is low, the amount of urine produced is low. Class X Science www.vedantu.com 36 37. How are fats digested in our bodies? Where does this process take place? Ans: The small intestine is where lipids are digested. The fats that enter the intestine take the form of big globules. These huge globules are broken down into smaller globules by bile juice. Following that, the fat digesting enzyme lipase, which is found in pancreatic and intestinal juice, turns it to fatty acids and glycerol. 38. What are the necessary conditions for autotrophic nutrition and what are its by- products? Ans: Conditions necessary for autotrophic nutrition are: (i) Light (ii) Chlorophyll (iii) Water and (iv) Carbon dioxide By-products are: (i) Oxygen and (ii) Water 39. What are the differences between aerobic and anaerobic respiration? Name some organisms that use anaerobic mode of respiration. Ans: The differences between aerobic and anaerobic respiration are: Aerobic Respiration Anaerobic Respiration Class X Science www.vedantu.com 37  In the presence of oxygen, it It happens when oxygen isn't present. occurs. It can be found in the cytoplasm It's found in the cytoplasm. and mitochondria. Complete breakdown of glucose. Incomplete breakdown of glucose. End products are CO 2 and H 2O. End products are CO 2 and ethyl alcohol or lactic acid. Yeast, bacteria, and some internal parasites, such as tapeworms, use anaerobic respiration. 40. How are the alveoli designed to maximize the exchange of gases? Ans: The alveolar walls are folded and have a significant surface area. It has a large network of blood arteries that serve as a surface for gas exchange. 41. What would be the consequence of a deficiency of hemoglobin in our bodies? Ans: Haemoglobin is a pigment found in red blood cells. It has a strong preference for oxygen. It transports oxygen from the lungs to other tissues that are oxygen- deficient. The presence of less haemoglobin reduces the oxygen supply to tissues. A person with low haemoglobin levels will become exhausted quickly and seem pale. Class X Science www.vedantu.com 38 42. What are the differences between the transport of materials in xylem and phloem? Ans: The differences between the transport of materials in xylem and phloem are: Xylem Phloem It transports water and minerals from It transport food materials from leaves root to leaves. to root and storage organs Only upwards transport of Substances are transported in both substances is possible. upward and downward directions. It consists of tracheids and vessels. It consists of sieve tubes and companion cells. 43. Compare the functioning of alveoli in the lungs and nephron in the kidneys with respect to their structure and functioning. Ans: Comparison between alveoli and nephron: Alveoli Nephron They have thin-walled balloon-like Nephron is a cluster of very thin walled structures. The alveoli provide a blood capillaries found in the kidney, surface extensively supplied with body Each capillary’s cluster remains capillaries for exchange of gases in associated with the cup-shaped end of a lungs. Carbon dioxide released in the tube called Bowman’s capsule that cavity of alveoli and oxygen is taken collects the filtered urine, at the same by haemoglobin present in RBC of time the useful substances are blood. reabsorbed. Class X Science www.vedantu.com 39 44. Leaves of a healthy potted plant were coated with petroleum jelly. How will it affect the plant? State two reasons. Ans: The plant will not remain healthy for long due to the following reasons: 1. There will be no transpiration. 2. There will be no exchange of gases which will affect the rate of photosynthesis. 45. How does respiration in plants differ from that in animals? Ans: In plants, all portions such as the root, stem, and leaves do individual respiration, but in animals, either the general body surface or particular organs such as the skin, gills, and lungs perform respiration. Plants have a significantly slower rate of respiration than animals. Gases are not transported from one section of the plant to another way they are in animals. 46. How does respiration in plants differ from that in animals? Ans: After eating a sugary food (chocolates and sweets), acid is generated in the mouth. The pH of the mouth is lowered by this acid. When the pH of the acid generated in the mouth falls below, tooth decay begins. This is because the acid develops strong enough to attack and damage the enamel of our teeth. 47. Name the cartilaginous flap which closes the glottis to check the entry of food into it during swallowing. Ans: It's possible that the tissue that became clogged was xylem. Water and minerals taken by roots from the soil are carried to the leaves and other parts of the plant via the xylem. As a result, if the xylem is obstructed, the leaves will be deprived of nutrients and will wilt. Class X Science www.vedantu.com 40 48. How does respiration in plants differ from that in animals? Ans: In plants, all portions such as the root, stem, and leaves do individual respiration, but in animals, either the general body surface or particular organs such as the skin, gills, and lungs perform respiration. Plants have a significantly slower rate of respiration than animals. Gases are not transported from one section of the plant to another way they are in animals. 49. Write one feature which is common to each of the following pairs of the term/org Ans: i) glycogen and starch Ans: The feature that is common to the following pair is Carbohydrate (food). ii) chlorophyll and haemoglobin Ans: The feature that is common to the following pair is Pigments. iii) gills and lungs Ans: The feature that is common to the following pair is Respiratory organs. iv) arteries and veins. Ans: The feature that is common to the following pair is Blood vessels. Class X Science www.vedantu.com 41 50. A certain tissue in a green plant somehow gets blocked and the leaves wilted. What was the tissue that got blocked? Ans: It's possible that the tissue that became clogged was xylem. Water and minerals taken by roots from the soil are carried to the leaves and other parts of the plant via the xylem. As a result, if the xylem is obstructed, the leaves will be deprived of nutrients and will wilt. 51. Write the functions of the following in the digestive process: i. Bile Ans: Bile: It is secreted by the gallbladder and it emulsifies & it into the smaller droplets for their easy digestion. ii. Bicarbonate secreted by the duodenal wall. Ans: It provides alkaline medium in the duodenum which is needed for the action of pancreatic enzymes of different food components for their digestion. iii. Pancreatic amylase. Ans: Pancreatic amylase enzyme digests starch and changes it into maltose. 52. The two openings of the pharynx, one leading to trachea and the other leading to oesophagus, lie very close to each other. Yet food we swallow normally does not enter into our trachea. Why? Ans: The food does not enter the trachea because the aperture leading to the trachea (glottis) is covered by a cartilaginous flap termed the epiglottis during swallowing, leaving the food with no other option except to go down the oesophagus. Class X Science www.vedantu.com 42 53. How would it affect the digestion of proteins and carbohydrates in the duodenum of man if there is a blockade in the pancreatic duct? Ans: The pancreatic juice is secreted by the pancreas and enters the duodenum. Pancreatic amylase and trypsin are enzymes that aid in the digestion of carbohydrates and proteins. As a result, if there is a blockade, carbohydrate and protein digestion is impaired. Long Answer Questions 5 Marks 1. What is ‘clotting of blood’? Write a flow chart showing major events taking place in clotting of blood? Ans: Formation of clot at the site of injury to stop bleeding is known as ‘clotting of blood’. Steps for clotting of blood – 2. With the help of a labelled diagram of the human excretory system, Mention its important part and explain them. Ans: A labelled diagram of human excretory system mentioning its important part Class X Science www.vedantu.com 43 with a proper explanation is as displayed below: 1. Kidney – It is the excretory system's functional unit. About a million small coiled channels called nephrons make up each kidney. The basic filtration unit in the kidneys is the nephron. Glomerulus, Bowman's capsule, and convoluted tubule are the components. 2. Ureter – Wastes come out of the kidney into the ureter. 3. Urinary bladder – Ureter pours its contents into a muscular sac called the urinary bladder. 4. Urethra – Urine flows from the bladder to the outside through the urethra. 3. (i) Draw a well labeled diagram of human digestive system Ans: A well labeled diagram of human digestive system is as shown below: Class X Science www.vedantu.com 44 (ii) Describe the role of following in digestion. a) Bile Ans: Bile – emulsification of fats b) Salivary amylase Ans: Salivary amylase – digest starch in mouth c) HCl Ans: HCl – Activate pepsinogen by making medium acidic in stomata. Class X Science www.vedantu.com 45 4. With the help of a labeled diagram, Discuss the mechanism of respiration in human beings. Ans: Mechanism of Respiration – It occurs in following steps a) Breathing – Taking in oxygen and expelling carbon – dioxide out is called breathing. It involves following steps – (i) Inhalation – It is consuming oxygen. It happens when the muscles linked to the ribcage contract. The ribs are lifted and the diaphragm is flattened, increasing the volume of the thoracic cavity. As a result, the pressure inside the thoracic cavity drops, allowing air to flow into the lungs. (ii) Exhalation – It is the process of releasing carbon dioxide. It happens when the muscles linked to the ribs relax and the diaphragm is formed. This reduces the volume of the thoracic cavity, lowers air pressure, and expels air from the lungs. Class X Science www.vedantu.com 46 b) Exchange of gases – It takes place between the alveoli of lungs and surrounding blood capillaries. c) Transport of gases in blood – Haemoglobin is a protein that transports oxygen throughout the body. In the form of any haemoglobin, oxygen is transported from the lungs to the bodily cells. d) Oxidation of food – Break down of glucose molecules which produce energy. It occurs in chondria. 5. Describe an experiment to prove that carbon – dioxide is essential for the process of photosynthesis. Ans: Experiment showing that carbon-dioxideis essential for photosynthesis. 1) Take a potted plant with elongated leaves 2) Take an empty bottle and put a little amount of potassium hydroxide ( KOH ) in it. 3) Now cut the cork of the bottle into two parts and place it on one of the leaves of the potted plant in between the two parts of the cork. 4) Now put the bottle in the presence of sunlight 72 – 96 hours. 5) Now test the leaf for the presence of starch. 6. Describe the structure and functioning of nephron. Ans: Each nephron is a collection of blood capillaries with very thin walls. Each glomerulus (capillary cluster) in the kidney is linked to the cup-shaped Bowman's capsule, which collects the filtered urine. The blood is filtered by the nephron to eliminate nitrogenous waste. Class X Science www.vedantu.com 47 They also absorb some vital substances from the filtrate, including glucose, amino acids, minerals, and a significant amount of water. 7. Describe double circulation in human beings. Why is it necessary? Ans: During each cycle, blood passes through the heart twice in mammals and birds. Double circulation is the term for this situation. Blood that has been deoxygenated enters the right auricle and then enters the right ventricle, where it is pushed to the lungs for oxygenation. It travels from the lungs to the left auricle, where it is oxygenated, and then to the left ventricle, where it is pumped to various regions of the body. Such a circulatory system prevents the mixing of oxygenated and deoxygenated blood, allowing for an effective supply of oxygen to the body. Class X Science www.vedantu.com 48