- Which blood component is primarily responsible for transporting oxygen?
(A) Red blood cells
(B) White blood cells
(C) Platelets
(D) Plasma
Answer: (A)
Explanation: Red blood cells contain hemoglobin, a protein that binds and transports oxygen from the lungs to tissues throughout the body. - Which hormone is secreted by the pancreas to increase blood sugar?
(A) Insulin
(B) Glucagon
(C) Thyroxine
(D) Adrenaline
Answer: (B)
Explanation: Glucagon, produced by the alpha cells of the pancreas, raises blood glucose levels by stimulating the conversion of glycogen to glucose in the liver. - Which vitamin is essential for vision and immune function?
(A) Vitamin A
(B) Vitamin B1
(C) Vitamin C
(D) Vitamin D
Answer: (A)
Explanation: Vitamin A is necessary for the formation of visual pigments in the retina and supports immune health. Its deficiency can cause night blindness. - Which process in plants releases water vapor through leaves?
(A) Respiration
(B) Photosynthesis
(C) Transpiration
(D) Fermentation
Answer: (C)
Explanation: Transpiration is the evaporation of water from plant leaves through stomata, which helps in cooling the plant and drawing water upward from roots. - Which organ in the human body filters blood to remove waste and forms urine?
(A) Liver
(B) Kidney
(C) Spleen
(D) Pancreas
Answer: (B)
Explanation: The kidneys filter metabolic waste, excess water, and toxins from the blood, producing urine for excretion. - Which mineral is essential for the formation of strong bones and teeth?
(A) Sodium
(B) Calcium
(C) Iron
(D) Zinc
Answer: (B)
Explanation: Calcium is a major component of bones and teeth, providing strength and structure. Its deficiency can lead to osteoporosis and dental problems. - Which enzyme breaks down proteins in the small intestine?
(A) Amylase
(B) Lipase
(C) Trypsin
(D) Maltase
Answer: (C)
Explanation: Trypsin, produced by the pancreas, digests proteins into smaller peptides in the small intestine. - Which hormone stimulates the production of milk after childbirth?
(A) Prolactin
(B) Oxytocin
(C) Estrogen
(D) Progesterone
Answer: (A)
Explanation: Prolactin, secreted by the pituitary gland, stimulates the mammary glands to produce milk after childbirth. - Which structure in the human eye regulates the amount of light entering?
(A) Cornea
(B) Iris
(C) Lens
(D) Retina
Answer: (B)
Explanation: The iris controls the size of the pupil, thus regulating the amount of light that enters the eye. - Which vitamin deficiency causes rickets in children?
(A) Vitamin A
(B) Vitamin B12
(C) Vitamin C
(D) Vitamin D
Answer: (D)
Explanation: Vitamin D is essential for calcium absorption and bone health. Its deficiency causes rickets, resulting in soft, weak bones in children. - Which blood vessel carries oxygenated blood from the heart to the body?
(A) Pulmonary vein
(B) Pulmonary artery
(C) Aorta
(D) Vena cava
Answer: (C)
Explanation: The aorta is the main artery that carries oxygen-rich blood from the left ventricle of the heart to the body. - Which hormone is responsible for the “fight or flight” response?
(A) Insulin
(B) Adrenaline
(C) Thyroxine
(D) Progesterone
Answer: (B)
Explanation: Adrenaline, secreted by the adrenal medulla, prepares the body to respond to stress by increasing heart rate, blood pressure, and energy availability. - Which part of the plant is responsible for absorbing water and minerals?
(A) Leaf
(B) Stem
(C) Root
(D) Flower
Answer: (C)
Explanation: Roots anchor the plant and absorb water and minerals from the soil, supplying them to the rest of the plant. - Which enzyme breaks down starch into maltose?
(A) Amylase
(B) Lipase
(C) Pepsin
(D) Trypsin
Answer: (A)
Explanation: Amylase, found in saliva and pancreatic juice, breaks down starch into maltose, a disaccharide sugar. - Which organ in the human body stores and concentrates bile?
(A) Liver
(B) Pancreas
(C) Gallbladder
(D) Stomach
Answer: (C)
Explanation: The gallbladder stores and concentrates bile produced by the liver, releasing it into the small intestine to aid in fat digestion. - Which vitamin is essential for blood clotting?
(A) Vitamin A
(B) Vitamin C
(C) Vitamin D
(D) Vitamin K
Answer: (D)
Explanation: Vitamin K is necessary for the synthesis of clotting factors, preventing excessive bleeding. - Which hormone regulates the basal metabolic rate in humans?
(A) Insulin
(B) Thyroxine
(C) Adrenaline
(D) Progesterone
Answer: (B)
Explanation: Thyroxine, produced by the thyroid gland, increases the basal metabolic rate, affecting how quickly the body uses energy. - Which structure in the human ear converts sound vibrations into nerve impulses?
(A) Ossicles
(B) Cochlea
(C) Eardrum
(D) Semicircular canals
Answer: (B)
Explanation: The cochlea is a spiral-shaped organ that converts sound vibrations into electrical signals for the brain to interpret as sound. - Which mineral is essential for muscle contraction and nerve transmission?
(A) Iron
(B) Calcium
(C) Magnesium
(D) Zinc
Answer: (B)
Explanation: Calcium ions are crucial for muscle contraction, nerve impulse transmission, and blood clotting. - Which hormone stimulates the release of glucose from the liver into the blood?
(A) Insulin
(B) Glucagon
(C) Thyroxine
(D) Cortisol
Answer: (B)
Explanation: Glucagon, produced by the pancreas, signals the liver to convert stored glycogen into glucose and release it into the blood. - Which part of the human skeleton protects the brain?
(A) Rib cage
(B) Pelvis
(C) Skull
(D) Vertebral column
Answer: (C)
Explanation: The skull is a bony structure that encases and protects the brain from injury. - Which vitamin deficiency causes night blindness?
(A) Vitamin A
(B) Vitamin B1
(C) Vitamin C
(D) Vitamin D
Answer: (A)
Explanation: Vitamin A deficiency impairs the production of rhodopsin in the retina, leading to night blindness. - Which hormone is responsible for stimulating uterine contractions during childbirth?
(A) Estrogen
(B) Progesterone
(C) Prolactin
(D) Oxytocin
Answer: (D)
Explanation: Oxytocin, released by the pituitary gland, stimulates powerful uterine contractions during labor and also aids milk ejection during breastfeeding. - Which enzyme breaks down fats in the digestive system?
(A) Amylase
(B) Lipase
(C) Pepsin
(D) Maltase
Answer: (B)
Explanation: Lipase, produced by the pancreas, breaks down dietary fats into fatty acids and glycerol in the small intestine. - Which organ in the human body is responsible for detoxifying drugs and alcohol?
(A) Kidney
(B) Liver
(C) Pancreas
(D) Spleen
Answer: (B)
Explanation: The liver metabolizes and detoxifies drugs, alcohol, and other harmful substances, making them less toxic for excretion. - Which process describes the movement of molecules from high to low concentration?
(A) Active transport
(B) Diffusion
(C) Endocytosis
(D) Exocytosis
Answer: (B)
Explanation: Diffusion is the passive movement of molecules down their concentration gradient, requiring no energy. - Which hormone stimulates the production of red blood cells?
(A) Insulin
(B) Erythropoietin
(C) Glucagon
(D) Thyroxine
Answer: (B)
Explanation: Erythropoietin, produced by the kidneys, stimulates the bone marrow to produce more red blood cells in response to low oxygen levels. - Which vitamin is essential for healthy skin and vision?
(A) Vitamin A
(B) Vitamin C
(C) Vitamin D
(D) Vitamin K
Answer: (A)
Explanation: Vitamin A is necessary for the maintenance of healthy skin, vision, and immune function. - Which hormone is responsible for stimulating milk ejection during breastfeeding?
(A) Oxytocin
(B) Prolactin
(C) Estrogen
(D) Progesterone
Answer: (A)
Explanation: Oxytocin causes the muscles around the mammary glands to contract, ejecting milk during breastfeeding. - Which part of the plant absorbs water and minerals from the soil?
(A) Leaf
(B) Stem
(C) Root
(D) Flower
Answer: (C)
Explanation: Roots anchor the plant and absorb water and minerals from the soil, supplying them to the rest of the plant. - Which vitamin deficiency causes beriberi?
(A) Vitamin B1
(B) Vitamin B2
(C) Vitamin B3
(D) Vitamin B12
Answer: (A)
Explanation: Beriberi is caused by a deficiency of thiamine (vitamin B1), affecting the nervous and cardiovascular systems. - Which hormone is responsible for the development of secondary sexual characteristics in females?
(A) Testosterone
(B) Estrogen
(C) Progesterone
(D) Insulin
Answer: (B)
Explanation: Estrogen, produced by the ovaries, promotes the development of female secondary sexual characteristics such as breast development and wider hips. - Which blood vessel carries deoxygenated blood from the body to the heart?
(A) Pulmonary vein
(B) Aorta
(C) Vena cava
(D) Pulmonary artery
Answer: (C)
Explanation: The vena cava (superior and inferior) carries deoxygenated blood from the body back to the right atrium of the heart. - Which enzyme breaks down proteins in the stomach?
(A) Amylase
(B) Lipase
(C) Pepsin
(D) Maltase
Answer: (C)
Explanation: Pepsin is a protease enzyme secreted by the stomach that digests proteins into smaller peptides. - Which hormone is responsible for the development of secondary sexual characteristics in males?
(A) Estrogen
(B) Testosterone
(C) Progesterone
(D) Insulin
Answer: (B)
Explanation: Testosterone, produced by the testes, promotes the development of male secondary sexual characteristics such as facial hair and deep voice. - Which mineral is essential for the synthesis of thyroid hormones?
(A) Calcium
(B) Iron
(C) Iodine
(D) Magnesium
Answer: (C)
Explanation: Iodine is a key component of thyroid hormones (T3 and T4), necessary for regulating metabolism. - Which process produces ATP in the absence of oxygen?
(A) Aerobic respiration
(B) Anaerobic respiration
(C) Photosynthesis
(D) Chemosynthesis
Answer: (B)
Explanation: Anaerobic respiration (fermentation) produces ATP without oxygen, but yields less energy than aerobic respiration. - Which vitamin is essential for the absorption of calcium from the intestine?
(A) Vitamin A
(B) Vitamin B12
(C) Vitamin C
(D) Vitamin D
Answer: (D)
Explanation: Vitamin D promotes the absorption of calcium from the intestine, which is vital for healthy bones and teeth. - Which hormone controls the reabsorption of water in the kidneys?
(A) Adrenaline
(B) Insulin
(C) Antidiuretic hormone
(D) Thyroxine
Answer: (C)
Explanation: Antidiuretic hormone (ADH), produced by the pituitary gland, increases water reabsorption in the kidneys to maintain fluid balance. - Which structure in the human brain controls voluntary muscle movements?
(A) Medulla oblongata
(B) Cerebellum
(C) Cerebrum
(D) Hypothalamus
Answer: (C)
Explanation: The cerebrum is responsible for voluntary muscle movements, reasoning, memory, and sensory perception. - Which vitamin deficiency causes scurvy?
(A) Vitamin A
(B) Vitamin B12
(C) Vitamin C
(D) Vitamin D
Answer: (C)
Explanation: Scurvy is caused by a deficiency of vitamin C, leading to bleeding gums, weakness, and poor wound healing. - Which hormone is responsible for stimulating uterine contractions during childbirth?
(A) Estrogen
(B) Progesterone
(C) Prolactin
(D) Oxytocin
Answer: (D)
Explanation: Oxytocin, released by the pituitary gland, stimulates powerful uterine contractions during labor and also aids milk ejection during breastfeeding. - Which enzyme breaks down proteins in the small intestine?
(A) Amylase
(B) Lipase
(C) Trypsin
(D) Maltase
Answer: (C)
Explanation: Trypsin, produced by the pancreas, digests proteins into smaller peptides in the small intestine. - Which organ in the human body stores bile?
(A) Liver
(B) Pancreas
(C) Gallbladder
(D) Stomach
Answer: (C)
Explanation: The gallbladder stores and concentrates bile produced by the liver, releasing it into the small intestine to aid in fat digestion. - Which hormone is responsible for stimulating milk production after childbirth?
(A) Prolactin
(B) Oxytocin
(C) Estrogen
(D) Progesterone
Answer: (A)
Explanation: Prolactin, secreted by the pituitary gland, stimulates the mammary glands to produce milk after childbirth. - Which mineral is essential for blood clotting?
(A) Iron
(B) Calcium
(C) Sodium
(D) Potassium
Answer: (B)
Explanation: Calcium is necessary for the activation of clotting factors and proper blood coagulation. - Which part of the human skeleton protects the spinal cord?
(A) Skull
(B) Rib cage
(C) Vertebral column
(D) Pelvis
Answer: (C)
Explanation: The vertebral column (spine) surrounds and protects the spinal cord from injury. - Which vitamin is essential for healthy skin and vision?
(A) Vitamin A
(B) Vitamin C
(C) Vitamin D
(D) Vitamin K
Answer: (A)
Explanation: Vitamin A is necessary for the maintenance of healthy skin, vision, and immune function. - Which hormone is responsible for the “fight or flight” response?
(A) Insulin
(B) Adrenaline
(C) Thyroxine
(D) Progesterone
Answer: (B)
Explanation: Adrenaline, secreted by the adrenal medulla, prepares the body to respond to stress by increasing heart rate, blood pressure, and energy availability. - Which process in plants produces glucose and oxygen using sunlight?
(A) Respiration
(B) Photosynthesis
(C) Fermentation
(D) Transpiration
Answer: (B)
Explanation: Photosynthesis is the process where plants use sunlight, carbon dioxide, and water to produce glucose and release oxygen. This occurs in the chloroplasts and is fundamental for plant energy and oxygen supply to the atmosphere.