Chapter 6 – Life Processes

Which of the following statements about the autotrophs is incorrect?

• (a)They synthesise carbohydrates from carbon dioxide and water in the presence of sunlight and chlorophyll
• (b)They store carbohydrates in the form of starch
• (c)They convert carbon dioxide and water into carbohydrates in the absence of sunlight
• (d)They constitute the first trophic level in food chains

In which of the following groups of organisms, food material is broken down outside the body and absorbed?

• (a)Mushroom, green plants, Amoeba
• (b)Yeast, mushroom, bread mould
• (c)Paramecium, Amoeba, Cuscuta
• (d)Cuscuta, lice, tapeworm

Select the correct statement

• (a)Heterotrophs do not synthesise their own food
• (b)Heterotrophs utilise solar energy for photosynthesis
• (c)Heterotrophs synthesise their own food
• (d)Heterotrophs are capable of converting carbon dioxide and water into carbohydrates

Which is the correct sequence of parts in human alimentary canal?

• (a)Mouth → stomach → small intestine → oesophagus → large intestine
• (b)Mouth →oesophagus → stomach → large intestine → small intestine
• (c)Mouth → stomach → oesophagus → small intestine → large intestine
• (d)Mouth → oesophagus → stomach → small intestine → large intestine

If salivary amylase is lacking in the saliva, which of the following events in the mouth cavity will be affected?

• (a)Proteins breaking down into amino acids
• (b)Starch breaking down into sugars
• (c)Fats breaking down into fatty acids and glycerol
• (d)Absorption of vitamins

The inner lining of stomach is protected by one of the following from hydrochloric acid. Choose the correct one

• (a)Pepsin
• (b)Mucus
• (c)Salivary amylase
• (d)Bile

Which part of alimentary canal receives bile from the liver?

• (a)Stomach
• (b)Small intestine
• (c)Large intestine
• (d)Oesophagus

A few drops of iodine solution were added to rice water. The solution turned blue-black in colour. This indicates that rice water contains

• (a)complex proteins
• (b)simple proteins
• (c)fats
• (d)starch

In which part of the alimentary canal food is finally digested?

• (a)Stomach
• (b)Mouth cavity
• (c)Large intestine
• (d)Small intestine

Choose the function of the pancreatic juice from the following

• (a)trypsin digests proteins and lipase carbohydrates
• (b)trypsin digests emulsified fats and lipase proteins
• (c)trypsin and lipase digest fats
• (d)trypsin digests proteins and lipase emulsified fats

When air is blown from mouth into a test-tube containing lime water, the lime water turned milky due to the presence of (a) oxygen (b) carbon dioxide (c) nitrogen (d) water vapour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oODU\Q[oSKDU\Q[oWUDFKHDoOXQJV E 1DVDOSDVVDJHoWUDFKHDoSKDU\Q[oODU\Q[oDOYHROL F ODU\Q[oQRVWULOVoSKDU\Q[oOXQJV G 1RVWULOVoSKDU\Q[oODU\Q[oWUDFKHDoDOYHROL  'XULQJUHVSLUDWLRQH[FKDQJHRIJDVHVWDNHSODFHLQ D WUDFKHDDQGODU\Q[ E DOYHROLRIOXQJV F DOYHROLDQGWKURDW G WKURDWDQGODU\Q[  ( ;(03/$5  3 52%/(06 ă6&,(1&( 17. Which of the following statement (s) is (are) true about heart?

• (i)Left atrium receives oxygenated blood from different parts of body while right atrium receives deoxygenated blood from lungs
• (ii)Left ventricle pumps oxygenated blood to different body parts while right ventricle pumps deoxygenated blood to lungs
• (iii)Left atrium transfers oxygenated blood to right ventricle which sends it to different body parts
• (iv)Right atrium receives deoxygenated blood from different parts of the body while left ventricle pumps oxygenated blood to different parts of the body (a) (i) (b) (ii) (c) (ii) and (iv) (d) (i) and (iii) 18. What prevents backflow of blood inside the heart during contraction? (a) Valves in heart (b) Thick muscular walls of ventricles (c) Thin walls of atria (d) All of the above 19. Single circulation i.e., blood flows through the heart only once during one cycle of passage through the body, is exhibited by (a) Labeo, Chameleon, Salamander (b) Hippocampus, Exocoetus, Anabas (c) Hyla, Rana, Draco (d) Whale, Dolphin, Turtle 20. In which of the following vertebrate group/groups, heart does not pump oxygenated blood to different parts of the body? (a) Pisces and amphibians (b) Amphibians and reptiles (c) Amphibians only (d) Pisces only 21. Choose the correct statement that describes arteries. (a) They have thick elastic walls, blood flows under high pressure; collect blood from different organs and bring it back to the heart (b) They have thin walls with valves inside, blood flows under low pressure and carry blood away from the heart to various organs of the body (c) They have thick elastic walls, blood flows under low pressure; carry blood from the heart to various organs of the body (d) They have thick elastic walls without valves inside, blood flows under high pressure and carry blood away from the heart to different parts of the body. LIFE PROCESSES 51 22. The filtration units of kidneys are called (a) ureter (b) urethra (c) neurons (d) nephrons 23. Oxygen liberated during photosynthesis comes from (a) water (b) chlorophyll (c) carbon dioxide (d) glucose 24. The blood leaving the tissues becomes richer in (a) carbon dioxide (b) water (c) heamoglobin (d) oxygen 25. Which of the following is an incorrect statement? (a) Organisms grow with time (b) Organisms must repair and maintain their structure (c) Movement of molecules does not take place among cells (d) Energy is essential for life processes 26. The internal (cellular) energy reserve in autotrophs is (a) glycogen (b) protein (c) starch (d) fatty acid 27. Which of the following equations is the summary of photosynthesis? (a) 6CO2 + 12H2O → C6H12O6 + 6O2+ 6H2O (b) 6CO2 + H2O + Sunlight→ C6H12O6 + O2+ 6H2O (c) 6CO2 + 12H2O + Chlorophyll + Sunlight→ C6H12O6 + 6O2+ 6H2O (d) 6CO2 + 12H2O + Chlorophyll + Sunlight→ C6H12O6 + 6CO2+ 6H2O 28. Choose the event that does not occur in photosynthesis (a) Absorption of light energy by chlorophyll (b) Reduction of carbon dioxide to carbohydrates (c) Oxidation of carbon to carbon dioxide (d) Conversion of light energy to chemical energy 52 E XEMPLAR P ROBLEMS – SCIENCE 29. The opening and closing of the stomatal pore depends upon (a) oxygen (b) temperature (c) water in guard cells (d) concentration of CO2 in stomata 30. Choose the forms in which most plants absorb nitrogen (i) Proteins (ii) Nitrates and Nitrites (iii) Urea (iv) Atmospheric nitrogen (a) (i) and (ii) (b) (ii) and (iii) (c) (iii) and (iv) (d) (i) and (iv) 31. Which is the first enzyme to mix with food in the digestive tract? (a) Pepsin (b) Cellulase (c) Amylase (d) Trypsin 32. Which of the following statement(s) is (are) correct? (i) Pyruvate can be converted into ethanol and carbon dioxide by yeast (ii) Fermentation takes place in aerobic bacteria (iii) Fermentation takes place in mitochondria (iv) Fermentation is a form of anaerobic respiration (a) (i) and (iii) (b) (ii) and (iv) (c) (i) and (iv) (d) (ii) and (iii) 33. Lack of oxygen in muscles often leads to cramps among cricketers. This results due to (a) conversion of pyruvate to ethanol (b) conversion of pyruvate to glucose (c) non conversion of glucose to pyruvate (d) conversion of pyruvate to lactic acid 34. Choose the correct path of urine in our body (a) kidney → ureter → urethra → urinary bladder (b) kidney → urinary bladder → urethra → ureter (c) kidney → ureters → urinary bladder → urethra (d) urinary bladder → kidney → ureter → urethra LIFE PROCESSES 53 35. During deficiency of oxygen in tissues of human beings, pyruvic acid is converted into lactic acid in the (a) cytoplasm (b) chloroplast (c) mitochondria (d) golgi body 5JQTV#PUYGT3WGUVKQPU 36. Name the following (a) The process in plants that links light energy with chemical energy (b) Organisms that can prepare their own food (c) The cell organelle where photosynthesis occurs (d) Cells that surround a stomatal pore (e) Organisms that cannot prepare their own food (f) An enzyme secreted from gastric glands in stomach that acts on proteins. 37. “All plants give out oxygen during day and carbon dioxide during night”. Do you agree with this statement? Give reason. 38. How do the guard cells regulate opening and closing of stomatal pores? 39. Two green plants are kept separately in oxygen free containers, one in the dark and the other in continuous light. Which one will live longer? Give reasons. 40. If a plant is releasing carbon dioxide and taking in oxygen during the day, does it mean that there is no photosynthesis occurring? Justify your answer. 41. Why do fishes die when taken out of water? 42. Differentiate between an autotroph and a heterotroph. 43. Is ‘nutrition’ a necessity for an organism? Discuss. 44. What would happen if green plants disappear from earth? 45. Leaves of a healthy potted plant were coated with vaseline. Will this plant remain healthy for long? Give reasons for your answer. 46. How does aerobic respiration differ from anaerobic respiration? 54 E XEMPLAR P ROBLEMS – SCIENCE 47. Match the words of Column (A) with that of Column (B) Column (A) Column (B) (a) Phloem (i) Excretion (b) Nephron (ii) Translocation of food (c) Veins (iii) Clotting of blood (d) Platelets (iv) Deoxygenated blood 48. Differentiate between an artery and a vein. 49. What are the adaptations of leaf for photosynthesis? 50. Why is small intestine in herbivores longer than in carnivores? 51. What will happen if mucus is not secreted by the gastric glands? 52. What is the significance of emulsification of fats? 53. What causes movement of food inside the alimentary canal? 54. Why does absorption of digested food occur mainly in the small intestine? 55. Match Group (A) with Group (B) Group (A) Group (B) (a) Autotrophic nutrition (i) Leech (b) Heterotrophic nutrition (ii) Paramecium (c) Parasitic nutrition (iii) Deer (d) Digestion in food vacuoles (iv) Green plant 56. Why is the rate of breathing in aquatic organisms much faster than in terrestrial organisms? 57. Why is blood circulation in human heart called double circulation? 58. What is the advantage of having four chambered heart? 59. Mention the major events during photosynthesis 60. In each of the following situations what happens to the rate of photosynthesis? (a) Cloudy days (b) No rainfall in the area (c) Good manuring in the area (d) Stomata get blocked due to dust 61. Name the energy currency in the living organisms. When and where is it produced? 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