Chapter 6 Life Processes

Question 1. 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

Question 2. 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

Question 3. 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

Question 4. 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

Question 5. 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

Question 6. 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

Question 7. Which part of alimentary canal receives bile from the liver?

(a) Stomach

(b) Small intestine

(c) Large intestine

(d) Oesophagus

Question 8. 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

Question 9. In which part of the alimentary canal food is finally digested?

(a) Stomach

(b) Mouth cavity

(c) Large intestine

(d) Small intestine

Question 10. 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

Question 11. 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

Question 12. The correct sequence of anaerobic reactions in yeast is

(a) Glucose Pyruvate Ethanol + Carbondioxide

(b) Glucose Pyruvate Lactic acid

(c) Glucose Pyruvate Lactic acid

(d) Glucose Pyruvate Ethanol + Carbondioxide

Question 13. Which of the following is most appropriate for aerobic respiration?

(a) Glucose Pyruvate CO2+H2O+ Energy

(b) Glucose Pyruvate CO2+H2O+ Energy

(c) Glucose Pyruvate + Energy CO2+H2O

(d) Glucose Pyruvate + Energy CO2+H2O+ Energy

Question 14. Which of the following statement(s) is (are) true about respiration?

(i) During inhalation, ribs move inward and diaphragm is raised

(ii) In the alveoli, exchange of gases takes place i.e., oxygen from alveolar air diffuses into blood and carbon dioxide from blood into alveolar air

(iii) Haemoglobin has greater affinity for carbon dioxide than oxygen

(iv) Alveoli increase surface area for exchange of gases

(a) (i) and (iv)

(b) (ii) and (iii)

(c) (i) and (iii)

(d) (ii) and (iv)

Question 15. Which is the correct sequence of air passage during inhalation?

(a) Nostrils ® larynx ® pharynx ® trachea ® lungs

(b) Nasal passage ® trachea ® pharynx ® larynx ® alveoli

(c) larynx ® nostrils ® pharynx ® lungs

(d) Nostrils ® pharynx ® larynx ® trachea ® alveoli

Question 16. During respiration exchange of gases take place in

(a) trachea and larynx

(b) alveoli of lungs

(c) alveoli and throat

(d) throat and larynx

Question 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)

Question 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

Question 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

Question 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

Question 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.

Question 22. The filtration units of kidneys are called

(a) ureter

(b) urethra

(c) neurons

(d) nephrons

Question 23. Oxygen liberated during photosynthesis comes from

(a) water

(b) chlorophyll

(c) carbon dioxide

(d) glucose

Question 24. The blood leaving the tissues becomes richer in

(a) carbon dioxide

(b) water

(c) heamoglobin

(d) oxygen

Question 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

Question 26. The internal (cellular) energy reserve in autotrophs is

(a) glycogen

(b) protein

(c) starch

(d) fatty acid

Question 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

Question 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

Question 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

Question 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)

Question 31. Which is the first enzyme to mix with food in the digestive tract?

(a) Pepsin

(b) Cellulase

(c) Amylase

(d) Trypsin

Question 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)

Question 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

Question 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

Question 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

Question 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.

Question 37. “All plants give out oxygen during day and carbon dioxide during night”. Do you agree with this statement? Give reason.

Question 38. How do the guard cells regulate opening and closing of stomatal pores?

Question 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.

Question 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.

Question 41. Why do fishes die when taken out of water?

Question 42. Differentiate between an autotroph and a heterotroph.

Question 43. Is ‘nutrition’ a necessity for an organism? Discuss.

Question 44. What would happen if green plants disappear from earth?

Question 45. Leaves of a healthy potted plant were coated with vaseline. Will this plant remain healthy for long? Give reasons for your answer.

Question 46. How does aerobic respiration differ from anaerobic respiration?

Question 47. Match the words of Column (A) with that of Column (B)

Group (A)

(i) Leech

(ii) Paramecium

(iii) Deer

(iv) Green plant

Group (B)

(a) Autotrophic nutrition

(b) Heterotrophic nutrition

(c) Parasitic nutrition

(d) Digestion in food vacuoles

Question 48. Differentiate between an artery and a vein.

Question 49. What are the adaptations of leaf for photosynthesis?

Question 50. Why is small intestine in herbivores longer than in carnivores?

Question 51. What will happen if mucus is not secreted by the gastric glands?

Question 52. What is the significance of emulsification of fats?

Question 53. What causes movement of food inside the alimentary canal?

Question 54. Why does absorption of digested food occur mainly in the small intestine?

Question 55. Match Group (A) with Group (B)

Column (A)

(a) Phloem

(b) Nephron

(c) Veins

(d) Platelets

Column (B)

(i) Excretion

(ii) Translocation of food

(iii) Clotting of blood

(iv) Deoxygenated blood

Question 56. Why is the rate of breathing in aquatic organisms much faster than in terrestrial organisms?

Question 57. Why is blood circulation in human heart called double circulation?

Question 58. What is the advantage of having four chambered heart?

Question 59. Mention the major events during photosynthesis

Question 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

Question 61. Name the energy currency in the living organisms. When and where is it produced?

Question 62. What is common for cuscuta, ticks and leeches?

Question 63. Explain the role of mouth in digestion of food.

Question 64. What are the functions of gastric glands present in the wall of the stomach?

Question 65. Match the terms in Column (A) with those in Column (B)

Column (A)

(a) Trypsin

(b) Amylase

(c) Bile

(d) Pepsin

Group (B)

(i) Pancreas

(ii) Liver

(iii) Gastric glands

(iv) Saliva

Question 66. Name the correct substrates for the following enzymes

(a) Trypsin

(b) Amylase

(c) Pepsin

(d) Lipase

Question 67. Why do veins have thin walls as compared to arteries?

Question 68. What will happen if platelets were absent in the blood?

Question 69. Plants have low energy needs as compared to animals. Explain.

Question 70. Why and how does water enter continuously into the root xylem?

Question 71. Why is transpiration important for plants?

Question 72. How do leaves of plants help in excretion?

Question 73. Explain the process of nutrition in Amoeba.

Question 74. Describe the alimentary canal of man.

Question 75. Explain the process of breathing in man.

Question 76. Explain the importance of soil for plant growth.

Question 77. Draw the diagram of alimentary canal of man and label the following parts.

Mouth, Oesophagus, Stomach, Intestine

Question 78. How do carbohydrates, proteins and fats get digested in human beings?

Question 79. Explain the mechanism of photosynthesis.

Question 80. Explain the three pathways of breakdown in living organisms.

Question 81. Describe the flow of blood through the heart of human beings.

Question 82. Describe the process of urine formation in kidneys.