Excretory Products and Their Elimination – Daily Practice Problem (DPP)

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🎯 NEET 2026 Daily Practice Problem (DPP)

Topic: Excretory Products and Their Elimination | 20 High-Yield MCQs

Q1. Which of the following is the most toxic nitrogenous waste requiring large amounts of water for its elimination?

  1. Urea
  2. Uric acid
  3. Ammonia
  4. Creatinine
✅ View Answer & Explanation

Correct Answer: (3) Ammonia
Explanation: Ammonia is highly toxic and readily soluble in water, so it is generally excreted by diffusion across body surfaces in aquatic animals (Ammonotelic).

Q2. Protonephridia (Flame cells) are the excretory structures in:

  1. Platyhelminthes (Planaria)
  2. Rotifers
  3. Cephalochordate (Amphioxus)
  4. All of the above
✅ View Answer & Explanation

Correct Answer: (4) All of the above
Explanation: Protonephridia are primarily concerned with osmoregulation and are found in flatworms, rotifers, some annelids, and Amphioxus.

Q3. The part of the kidney where the ureter, blood vessels, and nerves enter is called:

  1. Cortex
  2. Medulla
  3. Hilum
  4. Pelvis
✅ View Answer & Explanation

Correct Answer: (3) Hilum
Explanation: Towards the centre of the inner concave surface of the kidney is a notch called hilum through which the ureter and vessels enter.

Q4. Podocytes are cells present in:

  1. Wall of the efferent arteriole
  2. Inner wall of Bowman’s capsule
  3. Lining of the PCT
  4. Lining of the DCT
✅ View Answer & Explanation

Correct Answer: (2) Inner wall of Bowman’s capsule
Explanation: Podocytes are arranged in an intricate manner leaving minute spaces called filtration slits or slit pores for ultrafiltration.

Q5. Which of the following is NOT part of the Renal Corpuscle (Malpighian Body)?

  1. Glomerulus
  2. Bowman’s capsule
  3. Henle’s loop
  4. Both 1 and 2
✅ View Answer & Explanation

Correct Answer: (3) Henle’s loop
Explanation: The Glomerulus along with Bowman’s capsule is called the Renal Corpuscle. Henle’s loop is part of the renal tubule.

Q6. On average, how much urea is excreted out per day by a healthy adult human?

  1. 10-15 gm
  2. 25-30 gm
  3. 50-60 gm
  4. 1-5 gm
✅ View Answer & Explanation

Correct Answer: (2) 25-30 gm
Explanation: A human adult excretes an average of 1 to 1.5 litres of urine per day, which contains 25-30 grams of urea.

Q7. The GFR (Glomerular Filtration Rate) in a healthy individual is approximately:

  1. 125 mL/min
  2. 180 Litres/day
  3. Both 1 and 2
  4. 500 mL/min
✅ View Answer & Explanation

Correct Answer: (3) Both 1 and 2
Explanation: GFR is 125 mL per minute, which calculates to 180 litres per day.

Q8. Conditional reabsorption of $Na^+$ and water takes place in which part of the nephron?

  1. PCT
  2. DCT
  3. Descending limb of Henle’s loop
  4. Ascending limb of Henle’s loop
✅ View Answer & Explanation

Correct Answer: (2) DCT
Explanation: Conditional reabsorption of sodium and water occurs in the Distal Convoluted Tubule (DCT) under the influence of hormones like Aldosterone and ADH.

Q9. Which part of the Henle’s loop is impermeable to water but allows transport of electrolytes?

  1. Descending limb
  2. Ascending limb
  3. Both limbs
  4. None of the limbs
✅ View Answer & Explanation

Correct Answer: (2) Ascending limb
Explanation: The descending limb is permeable to water but impermeable to electrolytes. The ascending limb is impermeable to water but permeable to electrolytes.

Q10. The counter-current mechanism operates between:

  1. Two limbs of Henle’s loop
  2. Two limbs of Vasa recta
  3. Both 1 and 2
  4. PCT and DCT
✅ View Answer & Explanation

Correct Answer: (3) Both 1 and 2
Explanation: The counter-current flow occurs in both the limbs of Henle’s loop and the vasa recta to maintain a high osmolarity in the medullary interstitium.

Q11. Antidiuretic hormone (ADH) acts on the kidneys to:

  1. Increase water reabsorption
  2. Decrease water reabsorption
  3. Increase salt excretion
  4. Decrease blood pressure
✅ View Answer & Explanation

Correct Answer: (1) Increase water reabsorption
Explanation: ADH (Vasopressin) facilitates water reabsorption from the latter parts of the tubule (DCT and Collecting duct), thereby preventing diuresis.

Q12. The JGA (Juxtaglomerular Apparatus) releases which enzyme in response to a fall in GFR?

  1. Renin
  2. Angiotensin
  3. Aldosterone
  4. Atrial Natriuretic Factor
✅ View Answer & Explanation

Correct Answer: (1) Renin
Explanation: A fall in GFR activates JG cells to release Renin, which initiates the RAAS (Renin-Angiotensin-Aldosterone System) to increase blood pressure and GFR.

Q13. ANF (Atrial Natriuretic Factor) is secreted by the heart to:

  1. Increase blood pressure
  2. Cause vasodilation
  3. Stimulate Renin release
  4. Increase sodium reabsorption
✅ View Answer & Explanation

Correct Answer: (2) Cause vasodilation
Explanation: ANF is released when blood pressure increases; it causes vasodilation and acts as a check on the RAAS to lower blood pressure.

Q14. Presence of glucose and ketone bodies in urine are indicative of:

  1. Renal calculi
  2. Diabetes insipidus
  3. Diabetes mellitus
  4. Glomerulonephritis
✅ View Answer & Explanation

Correct Answer: (3) Diabetes mellitus
Explanation: Glycosuria (glucose in urine) and Ketonuria (ketones in urine) are classic clinical indicators of Diabetes mellitus.

Q15. The process of release of urine is called:

  1. Micturition
  2. Parturition
  3. Dialysis
  4. Ultrafiltration
✅ View Answer & Explanation

Correct Answer: (1) Micturition
Explanation: Micturition is the neural reflex-mediated process of emptying the urinary bladder.

Q16. Stones or insoluble mass of crystallized salts formed within the kidney are called:

  1. Bright’s disease
  2. Renal calculi
  3. Uremia
  4. Cystitis
✅ View Answer & Explanation

Correct Answer: (2) Renal calculi
Explanation: These are usually composed of oxalates and can cause severe pain and blockage in the urinary tract.

Q17. Haemodialysis is used for patients suffering from:

  1. Ketonuria
  2. Uremia
  3. Glycosuria
  4. Goitre
✅ View Answer & Explanation

Correct Answer: (2) Uremia
Explanation: Accumulation of urea in the blood (Uremia) due to kidney failure can be managed by artificial removal of urea via haemodialysis.

Q18. Sweat contains which of the following excretory products?

  1. NaCl
  2. Small amounts of urea
  3. Lactic acid
  4. All of the above
✅ View Answer & Explanation

Correct Answer: (4) All of the above
Explanation: Sweat produced by sudoriferous glands helps in cooling and also eliminates salt, urea, and lactic acid.

Q19. The osmolarity of the inner medullary interstitium is maintained at about:

  1. 300 mOsmol/L
  2. 600 mOsmol/L
  3. 900 mOsmol/L
  4. 1200 mOsmol/L
✅ View Answer & Explanation

Correct Answer: (4) 1200 mOsmol/L
Explanation: Osmolarity increases from 300 in the cortex to 1200 mOsmol/L in the inner medulla, helping in the concentration of urine.

Q20. In the absence of ADH, urine becomes:

  1. Hypertonic
  2. Hypotonic
  3. Isotonic
  4. Bloody
✅ View Answer & Explanation

Correct Answer: (2) Hypotonic
Explanation: Without ADH, the distal parts of the nephron remain impermeable to water, resulting in the excretion of a large volume of dilute (hypotonic) urine.

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