Urine Formation — NEET Biology MCQs with Solutions
Free NEET Biology Urine Formation MCQs with step-by-step solutions (54 questions). Part of Excretory Products and Their Elimination. Practise online on Prepizo — no login needed.
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Questions with solutions
Q1 — Urine Formation · easy · theory
The three basic processes involved in urine formation are:
A. Ingestion, digestion and egestion
B. Diffusion, osmosis and active transport
C. Glomerular filtration, reabsorption and secretion ✓ Correct
D. Filtration, digestion and absorption
Solution: Urine formation = glomerular filtration → tubular reabsorption → tubular secretion.
Q2 — Urine Formation · easy · theory
The filtration of blood at the glomerulus is called ______ because it filters everything except large proteins and cells:
A. Osmosis
B. Ultrafiltration ✓ Correct
C. Reabsorption
D. Secretion
Solution: Ultrafiltration under blood pressure passes water and small solutes into Bowman's capsule, retaining proteins/cells.
Q3 — Urine Formation · medium · theory
The amount of filtrate formed by the kidneys per minute is the Glomerular Filtration Rate (GFR), which in a healthy adult is about:
A. 1000 mL/min
B. 500 mL/min
C. 125 mL/min ✓ Correct
D. 25 mL/min
Solution: GFR ≈ 125 mL/min (~180 L/day); most is reabsorbed, leaving ~1.5 L of urine per day.
Q4 — Urine Formation · medium · theory
Tubular secretion of H⁺, K⁺ and NH₃ into the filtrate is important for:
A. Maintaining the ionic and acid-base (pH) balance of body fluids ✓ Correct
B. Storing urine
C. Filtering blood cells
D. Reabsorbing glucose
Solution: Secretion of H⁺/K⁺/NH₃ helps maintain the pH and electrolyte balance of blood.
Q5 — Urine Formation · hard · theory
The GFR is regulated by the JGA through the renin-angiotensin mechanism: a fall in GFR causes the JG cells to release ______:
A. Insulin
B. Renin (which raises blood pressure and GFR) ✓ Correct
C. ADH
D. Aldosterone directly
Solution: Low GFR → renin release → angiotensin II → vasoconstriction + aldosterone → restores GFR/BP.
Q6 — Urine Formation · hard · theory
If about 180 L of filtrate is formed daily but only ~1.5 L of urine is voided, this shows that:
A. All filtrate becomes urine
B. The kidneys filter very little
C. No reabsorption occurs
D. Nearly 99% of the filtrate is reabsorbed by the tubules ✓ Correct
Solution: The tubules reabsorb about 99% of the filtrate (water, glucose, ions), concentrating waste into a small urine volume.
Q7 — Urine Formation · easy · numerical
The main force that drives fluid out of the glomerular capillaries into the Bowman's capsule is the:
A. Active pumping of water by the podocytes
B. Hydrostatic pressure of fluid already inside the capsule
C. Colloidal osmotic pressure of the plasma proteins
D. High glomerular (blood) hydrostatic pressure ✓ Correct
Solution: Filtration is driven by the high glomerular blood hydrostatic pressure, which is opposed by the plasma colloidal osmotic pressure and the capsular hydrostatic pressure.
Q8 — Urine Formation · easy · numerical
Of the total glomerular filtrate formed, the fraction reabsorbed back into the blood by the renal tubules is nearly:
A. 99 per cent ✓ Correct
B. 10 per cent
C. 25 per cent
D. 50 per cent
Solution: About 99% of the filtrate is reabsorbed by the tubules, so only around 1% is finally voided as urine.
Q9 — Urine Formation · easy · numerical
In a healthy person, glucose is normally absent from the urine because:
A. It is destroyed by enzymes present in the collecting duct
B. It is too large a molecule to pass through the filtration membrane
C. It is secreted back into the blood by the vasa recta
D. It is completely reabsorbed from the filtrate by active transport in the tubule ✓ Correct
Solution: Glucose is freely filtered but is entirely reabsorbed (mainly in the PCT) by active transport, so it does not normally appear in urine.
Q10 — Urine Formation · easy · numerical
Conditional (facultative) reabsorption of water and sodium ions, adjusted according to the body's needs, occurs mainly in the:
A. Glomerulus and Bowman's capsule
B. Distal convoluted tubule and collecting duct ✓ Correct
C. Afferent and efferent arterioles
D. Descending limb of the loop of Henle only
Solution: The DCT and collecting duct carry out conditional reabsorption under hormonal control (ADH, aldosterone), fine-tuning the final volume and concentration of urine.
Q11 — Urine Formation · medium · numerical
The process of glomerular filtration is described as ultrafiltration because:
A. Only water and no dissolved solutes are able to cross the membrane
B. Everything in the plasma except large proteins and blood cells passes through the filtering membrane ✓ Correct
C. Filtration occurs against the direction of the blood pressure gradient
D. The filtrate contains large amounts of red blood cells and plasma proteins
Solution: In ultrafiltration the fine glomerular membrane lets water and small solutes through but retains blood cells and most plasma proteins, so the filtrate is nearly protein-free plasma.
Q12 — Urine Formation · medium · numerical
If the glomerular filtration rate is about 125 mL per minute, the volume of filtrate formed by both kidneys in 24 hours is approximately:
A. 18 litres
B. 1080 litres
C. 1.5 litres
D. 180 litres ✓ Correct
Solution: 125 mL/min × 60 × 24 ≈ 180,000 mL, i.e. about 180 litres of filtrate per day, of which nearly all is reabsorbed.
Q13 — Urine Formation · medium · numerical
The kidneys receive a very large share of the blood pumped by the heart. Roughly what fraction of the blood is filtered by the kidneys, amounting to about 1100–1200 mL per minute?
A. About one-fiftieth of the blood pumped by the heart
B. About four-fifths of the blood pumped by the heart
C. About one-half of the blood pumped by the heart
D. About one-fifth of the blood pumped by the heart ✓ Correct
Solution: The kidneys process roughly 1100–1200 mL of blood each minute, which is about one-fifth (1/5) of the blood pumped by the heart.
Q14 — Urine Formation · medium · numerical
Assertion (A): The glomerular filtrate is almost identical to plasma except that it lacks plasma proteins. Reason (R): The glomerular filtration membrane holds back molecules larger than the pore size, such as most plasma proteins, while letting smaller solutes pass. Choose the correct option.
A. A is true but R is false
B. Both A and R are true but R is NOT the correct explanation of A
C. A is false but R is true
D. Both A and R are true and R is the correct explanation of A ✓ Correct
Solution: The size-selective filtration barrier retains large plasma proteins, so the filtrate resembles protein-free plasma; hence R correctly explains A.
Q15 — Urine Formation · medium · numerical
Which of the following correctly pairs the tubular process with an example of the substance handled?
A. Tubular secretion — glucose and amino acids returned to the blood
B. Selective reabsorption — potassium ions actively pushed into the filtrate
C. Glomerular filtration — plasma proteins passing freely into the tubule
D. Tubular secretion — H⁺, K⁺ and NH₃ moved from blood into the filtrate ✓ Correct
Solution: Tubular secretion transfers H⁺, K⁺ and ammonia from the blood into the filtrate, helping maintain the ionic and acid–base balance of body fluids.
Q16 — Urine Formation · medium · numerical
During the reabsorption of substances from the filtrate, which of the following is chiefly reabsorbed by an ACTIVE (energy-requiring) transport mechanism?
A. Most of the chloride ions following sodium passively
B. Urea diffusing down its concentration gradient
C. A major part of the water
D. Glucose and amino acids ✓ Correct
Solution: Glucose and amino acids are reabsorbed by active transport, whereas most water is reabsorbed passively and much of the chloride follows sodium along electrochemical gradients.
Q17 — Urine Formation · easy
Urine formation involves
A. Ultrafiltration and reabsorption occurring in different parts of nephron
B. Ultrafiltration and reabsorption occurring in same part of nephron
C. Ultrafiltration, reabsorption and secretion occurring in same part of nephron
D. Ultrafiltration, reabsorption and secretion occurring in different parts of nephron ✓ Correct
Solution: Urine formation involves three main processes - glomerular filtration (ultrafiltration), reabsorption and secretion - which take place in different parts of the nephron.
Q18 — Urine Formation · medium
Match Column I with Column II. A. PCT; B. DCT; C. Loop of Henle; D. Counter-current mechanism; E. Renal corpuscle. I. Concentrated urine formation; II. Filtration of blood; III. Reabsorption of 70-80% electrolytes; IV. Ionic balance; V. Maintenance of concentration gradient in medulla.
A. A-III, B-I, C-IV, D-V, E-II
B. A-III, B-V, C-IV, D-II, E-I
C. A-I, B-III, C-II, D-V, E-IV
D. A-III, B-IV, C-I, D-V, E-II ✓ Correct
Solution: PCT reabsorbs 70-80% electrolytes (III); DCT maintains ionic balance (IV); Loop of Henle helps in concentrated urine formation (I); counter-current mechanism maintains the concentration gradient in the medulla (V); renal corpuscle filters blood (II).
Q19 — Urine Formation · medium
Which of the following statements is/are correct? I. Renal vein takes blood away from kidney. II. Loop of Henle conserves water. III. Podocytes occur in inner wall of Bowman's capsule. IV. Ultrafiltrate (nephric filtrate) is plasma minus proteins.
A. I and III
B. III and IV
C. I and II
D. I, II, III, IV ✓ Correct
Solution: All four statements are correct: the renal vein carries blood away from the kidney, the loop of Henle conserves water, podocytes line the inner (visceral) wall of Bowman's capsule, and the ultrafiltrate is essentially plasma minus proteins.
Q20 — Urine Formation · easy
The glomerular capillaries cause filtration of blood through how many layers?
A. 2
B. 6
C. 1
D. 3 ✓ Correct
Solution: Blood is filtered through three layers - the endothelium of glomerular blood vessels, the epithelium of Bowman's capsule, and the basement membrane between these two layers.
Q21 — Urine Formation · medium
The layers between the blood in the glomerulus and the Bowman's space are:
A. Endothelium of glomerular blood vessel + Endothelium of Bowman's capsule + Parietal layer of Bowman's capsule
B. Tunica media + Epithelium of Bowman's capsule + Endothelium of Bowman's capsule
C. Endothelium + Epithelium of Bowman's capsule + Basement membrane between the 2 layers ✓ Correct
D. Tunica media + Cuboidal epithelium + Basement membrane
Solution: The filtration barrier consists of the endothelium of glomerular capillaries, the epithelium (podocytes) of Bowman's capsule, and the basement membrane lying between these two layers.
Q22 — Urine Formation · easy
On average, ____ mL of blood is filtered by the kidney per minute, which constitutes roughly ____ of the blood pumped out by each ventricle of the heart in a minute.
A. 100-125 mL, 1/6th
B. 5 L, 1/10th
C. 125 mL, 1/6th
D. 1100-1200 mL, 1/5th ✓ Correct
Solution: About 1100-1200 mL of blood is filtered by the kidneys per minute, which is roughly one-fifth of the blood pumped out by each ventricle of the heart per minute.
Q23 — Urine Formation · easy
The amount of filtrate formed by the kidneys per minute is called GFR (Glomerular Filtration Rate). The GFR of a healthy adult is
A. 300 mL/min
B. 20 mL/min
C. 80 mL/min
D. 125 mL/min ✓ Correct
Solution: The glomerular filtration rate (GFR) in a healthy individual is approximately 125 mL of filtrate per minute.
Q24 — Urine Formation · easy
The GFR per day in a healthy adult is
A. 180 L ✓ Correct
B. 5 L
C. 200 L
D. 20 L
Solution: At a GFR of about 125 mL/min, roughly 180 litres of filtrate are formed per day.
Q25 — Urine Formation · medium
The juxtaglomerular apparatus, a special sensitive cellular region, is formed in
A. PCT and loop of Henle at the location of their contact
B. PCT and DCT at the location of their contact
C. PCT and DCT
D. DCT and afferent arteriole at the location of their contact ✓ Correct
Solution: The juxtaglomerular apparatus (JGA) is a specialised region formed by cellular modifications at the location where the DCT comes in contact with the afferent arteriole.
Q26 — Urine Formation · easy
Of the filtrate, nearly how much of it is reabsorbed by the renal tubules?
A. 99% ✓ Correct
B. 50%
C. 5%
D. 25%
Solution: Nearly 99% of the filtrate is reabsorbed by the renal tubules; only about 1% is excreted as urine.
Q27 — Urine Formation · medium
Which of the following statements is false?
A. During urine formation tubular cells secrete H+, K+ and NH3 into the filtrate
B. The kidney has built-in mechanisms for regulation of GFR
C. Tubular secretion does not play any significant role in urine formation ✓ Correct
D. The amount of urine output per day in a normal adult is about 1.5 L
Solution: Tubular secretion is an important step in urine formation - tubular cells secrete substances like H+, K+ and NH3 into the filtrate, helping maintain the ionic and acid-base balance. Hence the statement that it plays no significant role is false.
Q28 — Urine Formation · medium
Which of the following statements about the proximal convoluted tubule (PCT) is false?
A. It is lined by simple cuboidal brush border epithelium which increases the surface area
B. PCT is not the site of selective secretion ✓ Correct
C. PCT helps to maintain the pH and ionic balance of body fluids
D. Nearly all the essential nutrients, 70-80% electrolytes and 70% H2O are reabsorbed by PCT
Solution: The PCT is indeed a site of selective secretion - it secretes H+, NH3 and K+ ions into the filtrate. Therefore, the statement that PCT is not the site of selective secretion is false.
Q29 — Urine Formation · medium
PCT helps to maintain the pH and ionic balance of body fluids by
A. Reabsorption of HCO3 from filtrate
B. Both (a) and (b) ✓ Correct
C. Secreting regulatory hormones like renin and angiotensinogen
D. Selective secretion of H+, NH3 and K+ ions into the filtrate
Solution: The PCT maintains pH and ionic balance both by selective secretion of H+, NH3 and K+ into the filtrate and by reabsorption of HCO3 from the filtrate.
Q30 — Urine Formation · medium
If the loop of Henle were absent from mammalian nephrons, which of the following is to be expected?
A. The urine will be more dilute ✓ Correct
B. There will be no urine formation
C. The urine will be more concentrated
D. There will be hardly any change in quality and quantity of urine formed
Solution: The loop of Henle, along with the counter-current mechanism, is responsible for concentrating urine by maintaining the osmotic gradient in the medulla. Without it, urine cannot be concentrated and would be more dilute.