1. What is the primary criterion to determine if something is alive?
a) Ability to reproduce
b) Ability to breathe
c) Presence of molecular movements
d) Ability to move visibly
Answer: c) Presence of molecular movements

2. Viruses are often debated as living or non-living because:
a) They lack oxygen
b) They cannot move visibly
c) They show no molecular movement outside a host
d) They have no DNA
Answer: c) They show no molecular movement outside a host

3. What are the processes that maintain life in organisms called?
a) Metabolism
b) Life processes
c) Respiration
d) Diffusion
Answer: b) Life processes

4. Which process converts food to a uniform energy source in organisms?
a) Nutrition
b) Respiration
c) Excretion
d) Photosynthesis
Answer: b) Respiration

5. The breakdown of food molecules in the body involves:
a) Oxidation-reduction reactions
b) Photosynthesis
c) Fermentation
d) Osmosis
Answer: a) Oxidation-reduction reactions

6. How do unicellular organisms like Amoeba obtain nutrition?
a) Using guard cells
b) By diffusion
c) Through vacuoles
d) By external enzymes
Answer: c) Through vacuoles

7. Stomata are responsible for:
a) Water absorption
b) Photosynthesis
c) Gas exchange in plants
d) Storing energy
Answer: c) Gas exchange in plants

8. The functional role of chlorophyll in plants is to:
a) Absorb water
b) Absorb sunlight
c) Store energy
d) Absorb nitrogen
Answer: b) Absorb sunlight

9. What substance is used in photosynthesis to reduce carbon dioxide?
a) Hydrogen
b) Oxygen
c) ATP
d) Enzymes
Answer: a) Hydrogen

10. What is stored in plants as an energy reserve?
a) Glucose
b) Starch
c) Cellulose
d) ATP
Answer: b) Starch

11. Which of the following is a form of autotrophic nutrition?
a) Fungi absorbing nutrients
b) Photosynthesis
c) Parasitism
d) Saprophytism
Answer: b) Photosynthesis

12. Heterotrophic organisms depend on autotrophs because:
a) They need nitrogen
b) They cannot produce food
c) They need sunlight
d) They require oxygen
Answer: b) They cannot produce food

13. Where does digestion of starch begin in humans?
a) Stomach
b) Small intestine
c) Mouth
d) Esophagus
Answer: c) Mouth

14. What enzyme is found in saliva?
a) Pepsin
b) Lipase
c) Amylase
d) Trypsin
Answer: c) Amylase

15. What is the primary function of bile?
a) Protein digestion
b) Fat emulsification
c) Carbohydrate breakdown
d) Absorption of minerals
Answer: b) Fat emulsification16. What is the role of hydrochloric acid in the stomach?

a) Absorbs nutrients
b) Creates acidic medium for enzymes
c) Neutralizes food
d) Protects stomach lining
Answer: b) Creates acidic medium for enzymes

17. What is the primary function of villi in the small intestine?
a) Secretes enzymes
b) Absorbs nutrients
c) Moves food forward
d) Produces bile
Answer: b) Absorbs nutrients

18. In humans, undigested food is sent to the:
a) Stomach
b) Small intestine
c) Large intestine
d) Pancreas
Answer: c) Large intestine

19. Which substance is produced during anaerobic respiration in muscles?
a) Lactic acid
b) Ethanol
c) Carbon dioxide
d) Pyruvate
Answer: a) Lactic acid

20. Where does aerobic respiration take place in cells?
a) Nucleus
b) Cytoplasm
c) Mitochondria
d) Chloroplast
Answer: c) Mitochondria

21. ATP stands for:
a) Adenosine triphosphate
b) Adenosine diphosphate
c) Adenosine monophosphate
d) Adenosine phosphate
Answer: a) Adenosine triphosphate

22. The exchange of gases in plants occurs through:
a) Phloem
b) Stomata
c) Chloroplasts
d) Guard cells
Answer: b) Stomata

23. What helps in the movement of water in tall plants?
a) Root pressure
b) Osmosis
c) Transpiration pull
d) Diffusion
Answer: c) Transpiration pull

24. In humans, the respiratory pigment is:
a) Myoglobin
b) Haemoglobin
c) Chlorophyll
d) ATP
Answer: b) Haemoglobin

25. Which structure increases the surface area for gas exchange in the lungs?
a) Bronchi
b) Alveoli
c) Diaphragm
d) Ribs
Answer: b) Alveoli

26. What is double circulation in humans?
a) Blood passes through the heart once in one cycle
b) Blood passes through the heart twice in one cycle
c) Blood moves only in veins
d) Blood flows without oxygen
Answer: b) Blood passes through the heart twice in one cycle

27. In plants, xylem is responsible for transporting:
a) Food
b) Water and minerals
c) Hormones
d) Gases
Answer: b) Water and minerals

28. What is the function of phloem in plants?
a) Water transport
b) Food transport
c) Gas exchange
d) Nutrient absorption
Answer: b) Food transport

29. The rhythmic contraction of muscles in the alimentary canal is called:
a) Digestion
b) Peristalsis
c) Emulsification
d) Respiration
Answer: b) Peristalsis

30. Which organ secretes bile?
a) Stomach
b) Liver
c) Pancreas
d) Intestine
Answer: b) Liver

31. The term “transpiration” in plants refers to the loss of:
a) Oxygen
b) Water vapor
c) Carbon dioxide
d) Energy
Answer: b) Water vapor

32. What is the primary function of nephrons in the kidney?
a) Absorption of nutrients
b) Filtration of blood
c) Respiration
d) Digestion
Answer: b) Filtration of blood

33. The excretory system in humans includes:
a) Lungs and kidneys
b) Kidneys, ureters, bladder, and urethra
c) Liver and pancreas
d) Stomach and intestines
Answer: b) Kidneys, ureters, bladder, and urethra

34. What substance is absorbed by lymph from the intestine?
a) Proteins
b) Fats
c) Glucose
d) Water
Answer: b) Fats

35. Which plant tissue is responsible for upward movement of water?
a) Phloem
b) Xylem
c) Cambium
d) Stomata
Answer: b) Xylem

36. The process of transporting food in plants is called:
a) Respiration
b) Transpiration
c) Translocation
d) Osmosis
Answer: c) Translocation

37. What causes dental caries?
a) Lack of brushing
b) Acid produced by bacteria acting on sugars
c) Excess fluoride
d) Loss of calcium
Answer: b) Acid produced by bacteria acting on sugars

38. What structure in humans prevents food from entering the windpipe?
a) Epiglottis
b) Diaphragm
c) Trachea
d) Pharynx
Answer: a) Epiglottis

39. What type of blood vessel carries blood away from the heart?
a) Arteries
b) Veins
c) Capillaries
d) Lymphatics
Answer: a) Arteries

40. Veins have valves to:
a) Pump blood
b) Stop the mixing of oxygenated blood
c) Prevent the backward flow of blood
d) Absorb oxygen
Answer: c) Prevent the backward flow of blood

41. The large intestine absorbs:
a) Nutrients
b) Oxygen
c) Water
d) Glucose
Answer: c) Water

42. The energy currency of cells is:
a) ATP
b) Glucose
c) Oxygen
d) Pyruvate
Answer: a) ATP

43. Which waste product is produced during protein metabolism?
a) Urea
b) Glucose
c) Oxygen
d) Starch
Answer: a) Urea

44. What is the name of the process by which plants lose water vapor through leaves?
a) Photosynthesis
b) Transpiration
c) Osmosis
d) Respiration
Answer: b) Transpiration

45. Which plant structure controls water loss?
a) Chloroplast
b) Guard cells
c) Phloem
d) Vascular bundles
Answer: b) Guard cells46. What is the function of guard cells in plants?

a) Transport water
b) Control stomatal opening and closing
c) Absorb sunlight
d) Store food
Answer: b) Control stomatal opening and closing

47. Which type of nutrition involves consuming complex organic substances?
a) Autotrophic
b) Heterotrophic
c) Photosynthesis
d) Saprophytic
Answer: b) Heterotrophic

48. The primary function of the respiratory system is to:
a) Produce energy
b) Exchange gases
c) Digest food
d) Transport nutrients
Answer: b) Exchange gases

49. In humans, the diaphragm plays an important role in:
a) Digestion
b) Respiration
c) Circulation
d) Excretion
Answer: b) Respiration

50. The structure that prevents backflow of blood in veins is called:
a) Valves
b) Villi
c) Alveoli
d) Capillaries
Answer: a) Valves

51. Where does the majority of water absorption take place in the human digestive system?
a) Stomach
b) Small intestine
c) Large intestine
d) Esophagus
Answer: c) Large intestine

52. The process by which green plants prepare their food is called:
a) Respiration
b) Photosynthesis
c) Fermentation
d) Transpiration
Answer: b) Photosynthesis

53. What is the primary byproduct of photosynthesis?
a) Carbon dioxide
b) Oxygen
c) Glucose
d) Water
Answer: b) Oxygen

54. The main site of digestion and absorption in the human body is:
a) Stomach
b) Small intestine
c) Large intestine
d) Liver
Answer: b) Small intestine

55. Which pigment is essential for photosynthesis?
a) Chlorophyll
b) Haemoglobin
c) Carotene
d) Myoglobin
Answer: a) Chlorophyll

56. What type of waste is excreted through the stomata in plants?
a) Oxygen
b) Urea
c) Carbon dioxide
d) Both a and c
Answer: d) Both a and c

57. What is the role of the nephron in the kidney?
a) Excretion
b) Filtration of blood
c) Respiration
d) Digestion
Answer: b) Filtration of blood

58. In plants, food is transported through:
a) Xylem
b) Phloem
c) Stomata
d) Roots
Answer: b) Phloem

59. What type of blood vessels connect arteries and veins?
a) Arterioles
b) Capillaries
c) Lymphatics
d) Venules
Answer: b) Capillaries

60. Which blood component helps in clotting?
a) White blood cells
b) Platelets
c) Red blood cells
d) Plasma
Answer: b) Platelets

61. The function of the epiglottis is to:
a) Regulate blood flow
b) Prevent food from entering the windpipe
c) Absorb oxygen
d) Support the larynx
Answer: b) Prevent food from entering the windpipe

62. Which organ produces insulin?
a) Liver
b) Pancreas
c) Gallbladder
d) Stomach
Answer: b) Pancreas

63. What connects the kidneys to the urinary bladder?
a) Urethra
b) Ureters
c) Nephrons
d) Renal artery
Answer: b) Ureters

64. The opening and closing of stomata depend on:
a) Guard cells
b) Xylem pressure
c) Light intensity
d) Phloem activity
Answer: a) Guard cells

65. What substance is removed during exhalation?
a) Nitrogen
b) Oxygen
c) Carbon dioxide
d) Hydrogen
Answer: c) Carbon dioxide

66. What helps in the absorption of fats in the small intestine?
a) Villi
b) Bile salts
c) Enzymes
d) Plasma
Answer: b) Bile salts

67. What is the primary function of the large intestine?
a) Digestion of proteins
b) Absorption of nutrients
c) Absorption of water
d) Transport of oxygen
Answer: c) Absorption of water

68. What is the main product of aerobic respiration?
a) Glucose
b) Lactic acid
c) Carbon dioxide and water
d) Pyruvate
Answer: c) Carbon dioxide and water

69. Which organ removes nitrogenous waste from the body?
a) Liver
b) Kidneys
c) Lungs
d) Heart
Answer: b) Kidneys

70. What structure in plants transports water?
a) Phloem
b) Xylem
c) Roots
d) Stomata
Answer: b) Xylem

71. What happens in the alveoli of the lungs?
a) Filtration of blood
b) Exchange of gases
c) Breakdown of food
d) Absorption of fats
Answer: b) Exchange of gases

72. Which part of the heart pumps oxygen-rich blood to the body?
a) Right atrium
b) Left atrium
c) Right ventricle
d) Left ventricle
Answer: d) Left ventricle

73. What regulates the passage of food from the stomach to the small intestine?
a) Villi
b) Sphincter muscle
c) Epiglottis
d) Esophagus
Answer: b) Sphincter muscle

74. Which organism uses anaerobic respiration?
a) Humans
b) Yeast
c) Fish
d) Birds
Answer: b) Yeast

75. What is the primary component of lymph?
a) Red blood cells
b) Platelets
c) Plasma
d) Haemoglobin
Answer: c) Plasma

76. Transpiration in plants helps in:
a) Photosynthesis
b) Cooling and water transport
c) Storage of food
d) Formation of oxygen
Answer: b) Cooling and water transport

77. What carries oxygen in the blood?
a) Platelets
b) Haemoglobin
c) White blood cells
d) Plasma
Answer: b) Haemoglobin

78. Which part of the plant absorbs nutrients from the soil?
a) Stems
b) Leaves
c) Roots
d) Xylem
Answer: c) Roots

79. What type of waste do plants store as resins and gums?
a) Oxygen
b) Nitrogenous wastes
c) Photosynthetic byproducts
d) Metabolic wastes
Answer: d) Metabolic wastes

80. What is the process of moving sugars in plants called?
a) Transpiration
b) Translocation
c) Diffusion
d) Osmosis
Answer: b) Translocation

81. Which is the largest part of the human digestive system?
a) Stomach
b) Large intestine
c) Small intestine
d) Liver
Answer: c) Small intestine

82. Which process releases the most energy?
a) Anaerobic respiration
b) Fermentation
c) Aerobic respiration
d) Photosynthesis
Answer: c) Aerobic respiration

83. What is the site of gas exchange in plants?
a) Xylem
b) Phloem
c) Stomata
d) Guard cells
Answer: c) Stomata

84. What type of energy transformation occurs during photosynthesis?
a) Chemical to light
b) Light to chemical
c) Heat to mechanical
d) Light to heat
Answer: b) Light to chemical

85. Which organ is not part of the human excretory system?
a) Liver
b) Kidney
c) Lungs
d) Intestines
Answer: d) Intestines

86. In double circulation, oxygenated and deoxygenated blood:
a) Mix in the heart
b) Never mix
c) Circulate once through the heart
d) Are stored in the lungs
Answer: b) Never mix

87. Which enzyme digests proteins in the stomach?
a) Amylase
b) Pepsin
c) Lipase
d) Trypsin
Answer: b) Pepsin

88. What regulates body temperature in humans?
a) Liver
b) Blood
c) Skin
d) Heart
Answer: b) Blood

89. Which gas is released during photosynthesis?
a) Carbon dioxide
b) Oxygen
c) Nitrogen
d) Methane
Answer: b) Oxygen

90. In which process is ATP directly used?
a) Gas exchange
b) Cellular respiration
c) Active transport
d) Photosynthesis
Answer: c) Active transport

91. What is the function of the urethra in humans?
a) Filter blood
b) Transport oxygen
c) Remove urine
d) Digest food
Answer: c) Remove urine

92. Which blood vessel carries oxygen-rich blood to the heart?
a) Aorta
b) Pulmonary vein
c) Pulmonary artery
d) Capillary
Answer: b) Pulmonary vein

93. The plant tissue responsible for upward water transport is:
a) Phloem
b) Xylem
c) Guard cells
d) Cambium
Answer: b) Xylem

94. What protects the lungs from collapsing?
a) Ribs
b) Diaphragm
c) Cartilage rings
d) Pleural fluid
Answer: c) Cartilage rings

95. What is stored in the human body as glycogen?
a) Protein
b) Fat
c) Glucose
d) ATP
Answer: c) Glucose

96. Which is a nitrogenous waste excreted by humans?
a) Oxygen
b) Ammonia
c) Urea
d) Nitrite
Answer: c) Urea

97. What aids in the digestion of fats in humans?
a) Saliva
b) Bile
c) Pepsin
d) Glucose
Answer: b) Bile

98. The presence of which molecule gives leaves their green color?
a) Xanthophyll
b) Chlorophyll
c) Phycocyanin
d) Anthocyanin
Answer: b) Chlorophyll

99. What type of waste do plants excrete into the soil?
a) Urea
b) Gums and resins
c) Oxygen
d) Carbon dioxide
Answer: b) Gums and resins

100. What organ in humans produces urea?
a) Lungs
b) Liver
c) Kidneys
d) Intestines
Answer: b) Liver