Excretory System : (āύāĻŋāσāϏ⧰āĻŖ āϤāĻ¨ā§āĻ¤ā§ā§°) : MCQs


Excretory System  : (āύāĻŋāσāϏ⧰āĻŖ āϤāĻ¨ā§āĻ¤ā§ā§°) : MCQs


Q1. Where is urea formed ? : āχāω⧰āĻŋāϝāĻŧāĻž āĻ•’āϤ āĻ—āĻ āĻŋāϤ āĻšāϝāĻŧ ?


(a) Kidney (b) Liver (c) Heart (d) Lungs


Ans: (b) Liver


Explanation: Urea is produced in the liver during the breakdown of proteins. The liver converts toxic ammonia into urea, which is then transported to the kidneys for excretion in urine.


āĻŦā§āϝāĻžāĻ–ā§āϝāĻž: āχāω⧰āĻŋāϝāĻŧāĻž āϞāĻŋāĻ­āĻžā§°āϤ āĻ—āĻ āĻŋāϤ āĻšāϝāĻŧāĨ¤ āĻĒā§ā§°’āϟāĻŋāύ āĻ­āĻžāĻ™āĻŋ āĻ‰ā§ŽāĻĒāĻ¨ā§āύ āĻšā§‹ā§ąāĻž āĻŦāĻŋāώāĻžāĻ•ā§āϤ ammonia āϞāĻŋāĻ­āĻžā§°ā§‡ āχāω⧰āĻŋāϝāĻŧāĻžāϤ āĻĒā§°āĻŋāĻŖāϤ āϕ⧰⧇ āφ⧰⧁ āĻĒāĻŋāĻ›āϤ āχ āĻ•āĻŋāĻĄāύāĻŋā§° āϜ⧰āĻŋāϝāĻŧāϤ⧇ āĻŽā§‚āĻ¤ā§ā§°ā§° āϏ⧈āϤ⧇ āĻŦāĻžāĻšāĻŋā§° āĻšāϝāĻŧāĨ¤


Q2. Yellow color of urine is due to ? : āĻŽā§‚āĻ¤ā§ā§°ā§° āĻšāĻžāϞāϧ⧀āϝāĻŧāĻž ā§°āĻ‚ āĻ•āĻŋāĻšā§° āĻŦāĻžāĻŦ⧇ āĻšāϝāĻŧ ?


(a) Hemoglobin (b) Urochrome (c) Melanin (d) Bilirubin


Ans: (b) Urochrome


Explanation: The yellow color of urine is due to the pigment urochrome, which is formed during the breakdown of hemoglobin in the body. āĻŦā§āϝāĻžāĻ–ā§āϝāĻž: āĻŽā§‚āĻ¤ā§ā§°ā§° āĻšāĻžāϞāϧ⧀āϝāĻŧāĻž ā§°āĻ‚ urochrome āύāĻžāĻŽā§° ā§°āĻžā§āϜāϕ⧰ āĻŦāĻžāĻŦ⧇ āĻšāϝāĻŧ, āϝāĻŋ āĻšāĻŋāĻŽā§‹āĻ—ā§āϞ⧋āĻŦāĻŋāύ āĻ­āĻžāĻ™āĻŋ āϏ⧃āĻˇā§āϟāĻŋ āĻšāϝāĻŧāĨ¤


Q3. What is the functional unit of the kidney ? : āĻ•āĻŋāĻĄāύāĻŋā§° āĻ•āĻžā§°ā§āϝāϕ⧰⧀ āĻāĻ•āĻ• āĻ•āĻŋ ?


(a) Neuron (b) Nephron (c) Alveoli (d) Artery


Ans: (b) Nephron


Explanation: Nephron is the structural and functional unit of the kidney responsible for filtration of blood and formation of urine. āĻŦā§āϝāĻžāĻ–ā§āϝāĻž: Nephron āĻ•āĻŋāĻĄāύāĻŋā§° āĻ—āĻ āύāĻ—āϤ āφ⧰⧁ āĻ•āĻžā§°ā§āϝāϕ⧰⧀ āĻāĻ•āĻ•, āϝāĻŋ ā§°āĻ•ā§āϤ āĻĒā§°āĻŋāĻļā§‹āϧāύ āϕ⧰āĻŋ āĻŽā§‚āĻ¤ā§ā§° āϤ⧈āϝāĻŧāĻžā§° āϕ⧰⧇āĨ¤


Q4. Dialysis is used for ? : Dialysis āĻ•āĻŋāĻšā§° āĻŦāĻžāĻŦ⧇ āĻŦā§āĻ¯ā§ąāĻšāĻžā§° āϕ⧰āĻž āĻšāϝāĻŧ ?


(a) Heart function (b) Kidney function (c) Lung function (d) Brain function


Ans: (b) Kidney function


Explanation: Dialysis is used when kidneys fail to filter waste from blood. It artificially removes waste and excess water from the body. āĻŦā§āϝāĻžāĻ–ā§āϝāĻž: āĻ•āĻŋāĻĄāύāĻŋ āϏāĻ āĻŋāĻ•āĻ­āĻžā§ąā§‡ āĻ•āĻžāĻŽ āύāϕ⧰āĻŋāϞ⧇ dialysis āĻŦā§āĻ¯ā§ąāĻšāĻžā§° āϕ⧰āĻž āĻšāϝāĻŧāĨ¤ āχāϝāĻŧāĻžā§° āϜ⧰āĻŋāϝāĻŧāϤ⧇ ā§°āĻ•ā§āϤ⧰ āĻ…āĻĒāĻĻā§ā§°āĻŦā§āϝ āφ⧰⧁ āĻ…āϤāĻŋāϰāĻŋāĻ•ā§āϤ āĻĒāĻžāύ⧀ āφāρāĻ¤ā§°ā§‹ā§ąāĻž āĻšāϝāĻŧāĨ¤


Q5. What is the pH of urine ? : āĻŽā§‚āĻ¤ā§ā§°ā§° pH āĻ•āĻŋāĻŽāĻžāύ ?


(a) 4 (b) 6 (c) 8 (d) 10


Ans: (b) 6


Explanation: Normal urine is slightly acidic with an average pH around 6, though it may vary depending on diet and health. āĻŦā§āϝāĻžāĻ–ā§āϝāĻž: āϏāĻžāϧāĻžā§°āĻŖāϤ⧇ āĻŽā§‚āĻ¤ā§ā§° āϏāĻžāĻŽāĻžāĻ¨ā§āϝ āĻ…āĻŽā§āϞ⧀āϝāĻŧ āĻšāϝāĻŧ āφ⧰⧁ āχāϝāĻŧāĻžā§° pH āĻĒā§ā§°āĻžāϝāĻŧ 6āĨ¤


Q6. Artificial kidney is called ? : āĻ•ā§ƒāĻ¤ā§ā§°āĻŋāĻŽ āĻ•āĻŋāĻĄāύāĻŋāĻ• āĻ•āĻŋ āĻŦ⧁āϞāĻŋ āĻ•ā§‹ā§ąāĻž āĻšāϝāĻŧ ?


(a) Pacemaker (b) Dialyzer (c) Ventilator (d) Filter


Ans: (b) Dialyzer


Explanation: A dialyzer is the machine used in dialysis that acts like an artificial kidney by filtering waste from blood. āĻŦā§āϝāĻžāĻ–ā§āϝāĻž: Dialyzer āĻšā§ˆāϛ⧇ dialysis āϤ āĻŦā§āĻ¯ā§ąāĻšā§ƒāϤ āϝāĻ¨ā§āĻ¤ā§ā§° āϝāĻŋāϝāĻŧ⧇ āĻ•ā§ƒāĻ¤ā§ā§°āĻŋāĻŽ āĻ•āĻŋāĻĄāύāĻŋā§° āĻĻ⧰⧇ āĻ•āĻžāĻŽ āϕ⧰āĻŋ ā§°āĻ•ā§āϤ āĻĒā§°āĻŋāĻļā§‹āϧāύ āϕ⧰⧇āĨ¤


Q7. When kidneys fail, what accumulates in blood ? : āĻ•āĻŋāĻĄāύāĻŋ āĻŦāĻŋāĻ•āϞ āĻšāϞ⧇ ā§°āĻ•ā§āϤāϤ āĻ•āĻŋ āϜāĻŽāĻž āĻšāϝāĻŧ ?


(a) Oxygen (b) Urea (c) Glucose (d) Calcium


Ans: (b) Urea


Explanation: When kidneys fail, nitrogenous wastes such as urea accumulate in the blood, causing a condition called uremia.


āĻŦā§āϝāĻžāĻ–ā§āϝāĻž: āĻ•āĻŋāĻĄāύāĻŋ āĻŦāĻŋāĻ•āϞ āĻšāϞ⧇ urea ā§° āĻĻ⧰⧇ āύāĻžāχāĻŸā§ā§°’āĻœā§‡āύāϝ⧁āĻ•ā§āϤ āĻ…āĻĒāĻĻā§ā§°āĻŦā§āϝ ā§°āĻ•ā§āϤāϤ āϜāĻŽāĻž āĻšāϝāĻŧ, āϝāĻžāĻ• uremia āĻŦ⧁āϞāĻŋ āĻ•ā§‹ā§ąāĻž āĻšāϝāĻŧāĨ¤


Q8. Number of kidneys in humans ? : āĻŽāĻžāύ⧁āĻšā§° āĻĻ⧇āĻšāϤ āĻ•āĻŋāĻŽāĻžāύāϟāĻž āĻ•āĻŋāĻĄāύāĻŋ āĻĨāĻžāϕ⧇ ?


(a) One (b) Two (c) Three (d) Four


Ans: (b) Two


Explanation: Humans normally have two kidneys located on either side of the spine in the abdominal cavity.


āĻŦā§āϝāĻžāĻ–ā§āϝāĻž: āĻŽāĻžāύ⧁āĻšā§° āĻĻ⧇āĻšāϤ āϏāĻžāϧāĻžā§°āĻŖāϤ⧇ āĻĻ⧁āϟāĻž āĻ•āĻŋāĻĄāύāĻŋ āĻĨāĻžāϕ⧇, āϝāĻŋāĻŦā§‹ā§° āĻŽā§‡ā§°ā§āĻĻāĻŖā§āĻĄā§° āĻĻ⧁āϝāĻŧā§‹āĻĢāĻžāϞ⧇ āĻ…ā§ąāĻ¸ā§āĻĨāĻŋāϤāĨ¤


Q9. Which organ filters blood ? : āϕ⧋āύ āĻ…āĻ‚āϗ⧇ ā§°āĻ•ā§āϤ āĻĒā§°āĻŋāĻļā§‹āϧāύ āϕ⧰⧇ ?


(a) Liver (b) Kidney (c) Heart (d) Lungs


Ans: (b) Kidney


Explanation: Kidneys filter blood to remove wastes, excess salts, and water, producing urine.


āĻŦā§āϝāĻžāĻ–ā§āϝāĻž: āĻ•āĻŋāĻĄāύāĻŋāϝāĻŧ⧇ ā§°āĻ•ā§āϤ āĻĒā§°āĻŋāĻļā§‹āϧāύ āϕ⧰āĻŋ āĻ…āĻĒāĻĻā§ā§°āĻŦā§āϝ āφ⧰⧁ āĻ…āϤāĻŋāϰāĻŋāĻ•ā§āϤ āĻĒāĻžāύ⧀ āφāρāϤ⧰āĻžāχ āĻŽā§‚āĻ¤ā§ā§° āĻ‰ā§ŽāĻĒāĻ¨ā§āύ āϕ⧰⧇āĨ¤


Q10. Nephron is found in ? : Nephron āĻ•’āϤ āĻĒā§‹ā§ąāĻž āϝāĻžāϝāĻŧ ?


(a) Heart (b) Kidney (c) Lung (d) Brain


Ans: (b) Kidney


Explanation: Nephrons are microscopic structures present in the kidneys responsible for filtration and urine formation. āĻŦā§āϝāĻžāĻ–ā§āϝāĻž: Nephron āĻ•āĻŋāĻĄāύāĻŋāϤ āĻĨāĻ•āĻž āĻ…āϤāĻŋ āϏ⧂āĻ•ā§āĻˇā§āĻŽ āĻ—āĻ āύ āϝāĻŋāϝāĻŧ⧇ ā§°āĻ•ā§āϤ āĻĒā§°āĻŋāĻļā§‹āϧāύ āϕ⧰āĻŋ āĻŽā§‚āĻ¤ā§ā§° āϏ⧃āĻˇā§āϟāĻŋ āϕ⧰⧇āĨ¤


Q11. What is urea? : āχāω⧰āĻŋāϝāĻŧāĻž āĻ•āĻŋ?


(a) Sugar (b) Protein (c) Nitrogenous waste (d) Fat


Ans: (c) Nitrogenous waste


Explanation: Urea is a nitrogenous waste product formed during protein metabolism in the liver. āĻŦā§āϝāĻžāĻ–ā§āϝāĻž: āχāω⧰āĻŋāϝāĻŧāĻž āĻšā§ˆāϛ⧇ āĻĒā§ā§°’āϟāĻŋāύ āĻŦāĻŋāĻĒāĻžāĻ• āĻĒā§ā§°āĻ•ā§ā§°āĻŋāϝāĻŧāĻžāϤ āϏ⧃āĻˇā§āϟāĻŋ āĻšā§‹ā§ąāĻž āύāĻžāχāĻŸā§ā§°’āĻœā§‡āύāϝ⧁āĻ•ā§āϤ āĻ…āĻĒāĻĻā§ā§°āĻŦā§āϝāĨ¤


Q12. Carbon dioxide is removed by ? : āĻ•āĻžā§°ā§āĻŦāύ āĻĄāĻžāχāĻ…āĻ•ā§āϏāĻžāχāĻĄ āϕ⧋āύ āĻ…āĻ‚āϗ⧇ āĻŦāĻžāĻšāĻŋā§° āϕ⧰⧇ ? 


(a) Kidney (b) Skin (c) Lungs (d) Liver


Ans: (c) Lungs


Explanation: Lungs remove carbon dioxide from the blood during respiration. āĻŦā§āϝāĻžāĻ–ā§āϝāĻž: āĻĢ⧁āϏāĻĢ⧁āϏāϝāĻŧ⧇ āĻļā§āĻŦāĻžāϏ-āĻĒā§ā§°āĻļā§āĻŦāĻžāϏ āĻĒā§ā§°āĻ•ā§ā§°āĻŋāϝāĻŧāĻžāϤ ā§°āĻ•ā§āϤ⧰ āĻĒā§°āĻž āĻ•āĻžā§°ā§āĻŦāύ āĻĄāĻžāχāĻ…āĻ•ā§āϏāĻžāχāĻĄ āφāρāϤ⧰āĻžāϝāĻŧāĨ¤


Q13 Main excretory organ of human body ? : āĻŽāĻžāύ⧁āĻšā§° āĻĻ⧇āĻšā§° āĻŽā§‚āϞ āύāĻŋāσāϏ⧰āĻŖ āĻ…āĻ‚āĻ— āĻ•āĻŋ ?


(a) Liver (b) Kidney (c) Heart (d) Skin


Ans: (b) Kidney


Explanation: Kidneys are the main organs responsible for removing metabolic wastes from the body. āĻŦā§āϝāĻžāĻ–ā§āϝāĻž: āĻ•āĻŋāĻĄāύāĻŋ āĻšā§ˆāϛ⧇ āĻŽāĻžāύ⧁āĻšā§° āĻĻ⧇āĻšā§° āĻŽā§‚āϞ āύāĻŋāσāϏ⧰āĻŖ āĻ…āĻ‚āĻ— āϝāĻŋāϝāĻŧ⧇ āĻ…āĻĒāĻĻā§ā§°āĻŦā§āϝ āĻŦāĻžāĻšāĻŋā§° āϕ⧰⧇āĨ¤


Q14. Sweat is released by ? : āϘāĻžāĻŽ āϕ⧋āύ⧇ āύāĻŋāσāϏ⧰āĻŖ āϕ⧰⧇ ?


(a) Kidney (b) Liver (c) Sweat glands (d) Lungs


Ans: (c) Sweat glands (āϘāĻžāĻŽ āĻ—ā§ā§°āĻ¨ā§āĻĨāĻŋ)


Explanation: Sweat is released by sweat glands present in the skin. It helps in excretion of small amounts of salt, water, and urea and also regulates body temperature.


āĻŦā§āϝāĻžāĻ–ā§āϝāĻž: Sweat glands āĻŦāĻž āϘāĻžāĻŽ āĻ—ā§ā§°āĻ¨ā§āĻĨāĻŋāϝāĻŧ⧇ āϘāĻžāĻŽ āύāĻŋāσāϏ⧰āĻŖ āϕ⧰⧇āĨ¤ āχāϝāĻŧāĻžā§° āϜ⧰āĻŋāϝāĻŧāϤ⧇ āĻĒāĻžāύ⧀, āĻ˛ā§ąāĻŖ āφ⧰⧁ āĻ…āϞāĻĒ āχāω⧰āĻŋāϝāĻŧāĻž āĻŦāĻžāĻšāĻŋā§° āĻšāϝāĻŧ āφ⧰⧁ āĻĻ⧇āĻšā§° āϤāĻžāĻĒāĻŽāĻžāĻ¤ā§āϰāĻž āύāĻŋāϝāĻŧāĻ¨ā§āĻ¤ā§ā§°āĻŖ āĻšāϝāĻŧāĨ¤