Given below are two statements: Statement I: NaCl carried out by the ascending limb of Henle's loop is exchanged with the descending limb of the vasa recta. Statement II: The osmolarity of the interstitial fluid falls from about 1200 mOsmol L⁻¹ in the cortex to about 300 mOsmol L⁻¹ in the inner medulla. Choose the correct answer.

Statement I is correct but Statement II is incorrect

Both Statement I and Statement II are correct

Statement I is incorrect but Statement II is correct

Both Statement I and Statement II are incorrect

Excretory Products and their Elimination

29 NEET-UG practice questions on Excretory Products and their Elimination, part of Zoology. The first 25 are below; the first 5 with answers and explanations (tap Show answer after you have chosen), the rest in Learn with a free account.

Question 1 · Easy
In haemodialysis, the dialysing fluid has the same composition as plasma except that it lacks
1. Aglucose
2. Bbicarbonate ions
3. Cnitrogenous wastes
4. Dsodium ions
Show answerHide answer
Answer: C · nitrogenous wastes
The dialysing fluid has the same composition as plasma except for nitrogenous wastes. The wastes therefore move out of the blood down their concentration gradient across the porous cellophane membrane, and the cleared blood is returned to the patient.
- A: Glucose is a plasma constituent, so it is not the missing component named in NCERT.
- B: Bicarbonate is a plasma constituent, so it is not the missing component named in NCERT.
- D: Sodium ions are kept in the fluid so that the patient does not lose them from the blood.
Remember this
The concentration gradient for nitrogenous wastes drives dialysis, because the fluid matches plasma in everything except those wastes.
Question 2 · Hard
Regarding the regulation of kidney function, consider the following: A. Excessive loss of fluid from the body can activate osmoreceptors, which stimulate the hypothalamus to release ADH. B. By constricting blood vessels, ADH can raise blood pressure and thereby the GFR. C. Aldosterone causes reabsorption of Na⁺ and water mainly from the proximal convoluted tubule. D. Atrial natriuretic factor causes vasodilation and acts as a check on the renin-angiotensin mechanism. Choose the correct answer.
1. AA, B and D only
2. BA and D only
3. CB, C and D only
4. DA, B and C only
Show answerHide answer
Answer: A · A, B and D only
A, B and D follow NCERT: osmoreceptors trigger ADH release, ADH has a constrictory effect that raises GFR, and ANF lowers blood pressure and opposes the renin-angiotensin mechanism. C is wrong because aldosterone acts on the distal parts of the tubule.
- B: This rejects B, overlooking the constrictory effect of ADH on blood vessels.
- C: This accepts C and rejects A, although osmoreceptors do trigger ADH release.
- D: This accepts C, which puts the action of aldosterone in the wrong part of the tubule.
Remember this
Aldosterone acts on the distal tubule parts; ANF is the check that opposes the renin-angiotensin mechanism.
Question 3 · Medium
A fall in glomerular blood pressure sets off a hormonal cascade. Which substance in this cascade both constricts blood vessels and activates the adrenal cortex to release aldosterone?
1. AAngiotensin II
2. BRenin
3. CAtrial natriuretic factor
4. DAngiotensin I
Show answerHide answer
Answer: A · Angiotensin II
JG cells release renin, which converts angiotensinogen to angiotensin I and then to angiotensin II. Angiotensin II is a powerful vasoconstrictor that raises glomerular blood pressure and GFR, and it also activates the adrenal cortex to release aldosterone.
- B: Renin starts the cascade by its action on angiotensinogen and does not itself act on the adrenal cortex.
- C: ANF causes vasodilation and acts as a check on this cascade.
- D: Angiotensin I is only the intermediate formed before angiotensin II.
Remember this
Angiotensin II raises GFR by vasoconstriction and raises reabsorption through aldosterone.
Question 4 · Medium
Given below are two statements: Statement I: NaCl carried out by the ascending limb of Henle's loop is exchanged with the descending limb of the vasa recta. Statement II: The osmolarity of the interstitial fluid falls from about 1200 mOsmol L⁻¹ in the cortex to about 300 mOsmol L⁻¹ in the inner medulla. Choose the correct answer.
1. ABoth Statement I and Statement II are correct
2. BStatement I is incorrect but Statement II is correct
3. CBoth Statement I and Statement II are incorrect
4. DStatement I is correct but Statement II is incorrect
Show answerHide answer
Answer: D · Statement I is correct but Statement II is incorrect
Statement I is the NCERT account of the counter-current exchange: NaCl from the ascending limb enters the descending vasa recta and is returned to the interstitium by the ascending vasa recta. Statement II reverses the gradient: osmolarity rises from about 300 mOsmol L⁻¹ in the cortex to about 1200 mOsmol L⁻¹ in the inner medulla.
- A: Statement II has the gradient upside down, so both cannot be correct.
- B: Statement I is correct and Statement II is the one that reverses the gradient.
- C: Statement I correctly describes the exchange between Henle's loop and the vasa recta.
Remember this
Medullary osmolarity rises inward from 300 to 1200 mOsmol L⁻¹, built by NaCl and urea.
Question 5 · Easy
A student compares sections of different nephron segments under a microscope. Which segment has a simple cuboidal brush border epithelium that enlarges the surface for reabsorption?
1. ACollecting duct
2. BProximal convoluted tubule
3. CBowman's capsule
4. DAscending limb of Henle's loop
Show answerHide answer
Answer: B · Proximal convoluted tubule
The proximal convoluted tubule is lined by simple cuboidal brush border epithelium, which increases the surface area for reabsorption. This is why nearly all essential nutrients and 70-80% of electrolytes and water are reabsorbed here.
- A: The collecting duct is a long duct that concentrates urine, and it is not the segment described by a brush border.
- C: Bowman's capsule is a double-walled cup around the glomerulus that receives the filtrate.
- D: Reabsorption in the ascending limb is minimum, and the brush border is a feature of the PCT.
Remember this
The PCT has the brush border and carries out the largest share of reabsorption in the nephron.
Question 6 · Easy
A healthy adult has a glomerular filtration rate of 125 mL per minute. What volume of filtrate do the kidneys form in 24 hours?
1. A18 L
2. B125 L
3. C7.5 L
4. D180 L
Answer and explanation in LearnFree account
Question 7 · Medium
Match List-I with List-II. List-I (nephron segment) A. Descending limb of Henle's loop B. Ascending limb of Henle's loop C. Proximal convoluted tubule D. Collecting duct List-II (feature) I. Reabsorbs large amounts of water and passes small amounts of urea into the medullary interstitium II. Reabsorbs nearly all essential nutrients and 70-80% of electrolytes and water III. Permeable to water but almost impermeable to electrolytes IV. Impermeable to water but allows transport of electrolytes
1. AA-III, B-IV, C-I, D-II
2. BA-IV, B-III, C-II, D-I
3. CA-III, B-IV, C-II, D-I
4. DA-IV, B-III, C-I, D-II
Answer and explanation in LearnFree account
Question 8 · Hard
A hypothetical drug stops electrolyte transport out of the ascending limb of Henle's loop, while every other segment works normally. Which early effect on urine is expected?
1. ASmaller volume of more concentrated urine, as the medullary gradient rises
2. BUnchanged volume and concentration, as ADH fully compensates for the block
3. CLarger volume of less concentrated urine, as the medullary gradient falls
4. DLarger volume with much glucose, as the PCT stops reabsorbing nutrients
Answer and explanation in LearnFree account
Question 9 · Medium
Given below are two statements about the pathway in the figure: Statement I: P is an enzyme released by the JG cells, and Q is angiotensin I. Statement II: R comes from the adrenal medulla and increases the loss of Na⁺ and water in urine. Choose the correct answer.
Figure: MedExams
1. ABoth Statement I and Statement II are incorrect
2. BStatement I is correct but Statement II is incorrect
3. CStatement I is incorrect but Statement II is correct
4. DBoth Statement I and Statement II are correct
Answer and explanation in LearnFree account
Question 10 · Medium
Osmolarity of the fluid is plotted along a human renal tubule, from Bowman's capsule to the collecting duct. Which marked segment is impermeable to water but allows electrolytes to leave the tubule?
Figure: MedExams
1. ASegment P
2. BSegment R
3. CSegment S
4. DSegment Q
Answer and explanation in LearnFree account
Question 11 · Easy
In most human nephrons, the loop of Henle is short and dips only a little into the medulla. These nephrons are called
1. Amedullary nephrons
2. Bcortical nephrons
3. Cjuxtamedullary nephrons
4. Dcollecting nephrons
Answer and explanation in LearnFree account
Question 12 · Hard
Given below are two statements: Statement I: NaCl transported by the ascending limb of Henle's loop is exchanged with the descending limb of the vasa recta. Statement II: Small amounts of urea enter the thin segment of the ascending limb of Henle's loop and are transported back to the interstitium by the collecting tubule. Choose the correct answer.
1. ABoth Statement I and Statement II are correct
2. BStatement I is correct but Statement II is incorrect
3. CBoth Statement I and Statement II are incorrect
4. DStatement I is incorrect but Statement II is correct
Answer and explanation in LearnFree account
Question 13 · Medium
An increase in blood flow to the atria of the heart causes the release of a factor that
1. Aconstricts blood vessels and raises blood pressure
2. Bincreases water reabsorption from the collecting duct
3. Ccauses vasodilation and lowers blood pressure
4. Dstimulates the adrenal cortex to release aldosterone
Answer and explanation in LearnFree account
Question 14 · Medium
A person's glomerular filtration rate is 120 mL per minute, and 99 per cent of the filtrate is reabsorbed by the tubules. How much urine is formed in one hour?
1. A72 mL
2. B7128 mL
3. C720 mL
4. D1.2 mL
Answer and explanation in LearnFree account
Question 15 · Medium
Match List-I with List-II. List-I (disorder) A. Uremia B. Renal calculi C. Glomerulonephritis D. Diabetes insipidus List-II (feature) I. Inflammation of the glomeruli of the kidney II. Loss of water due to impaired ADH synthesis or release III. Accumulation of urea in the blood IV. Stone or insoluble mass of crystallised salts formed in the kidney Choose the correct answer.
1. AA-IV, B-III, C-I, D-II
2. BA-III, B-IV, C-I, D-II
3. CA-III, B-IV, C-II, D-I
4. DA-I, B-IV, C-III, D-II
Answer and explanation in LearnFree account
Question 16 · Easy
Arrange these parts of a nephron in the order in which the filtrate flows through them. A. Distal convoluted tubule B. Bowman's capsule C. Henle's loop D. Proximal convoluted tubule
1. AB, D, C, A
2. BD, B, C, A
3. CB, D, A, C
4. DB, C, D, A
Answer and explanation in LearnFree account
Question 17 · Medium
The initial glomerular filtrate has an osmolarity of about 300 mOsmol L⁻¹, and human kidneys can produce urine nearly four times as concentrated as this filtrate. What is the approximate osmolarity of the most concentrated urine?
1. AAbout 1200 mOsmol L⁻¹
2. BAbout 600 mOsmol L⁻¹
3. CAbout 75 mOsmol L⁻¹
4. DAbout 304 mOsmol L⁻¹
Answer and explanation in LearnFree account
Question 18 · Medium
When the urinary bladder fills, stretch receptors in its wall send signals to the CNS. Which motor response then brings about micturition?
1. AContraction of the bladder's smooth muscles with relaxation of the urethral sphincter
2. BRelease of ADH to empty the bladder
3. CRelaxation of the bladder's smooth muscles with contraction of the urethral sphincter
4. DContraction of both the bladder muscles and the urethral sphincter
Answer and explanation in LearnFree account
Question 19 · Medium
Assertion A: Adaptation to life on land favoured the excretion of less toxic nitrogenous wastes such as urea and uric acid. Reason R: Ammonia, being highly toxic, needs a large amount of water for its elimination. Choose the correct answer.
1. AA is not correct but R is correct
2. BBoth A and R are correct and R is the correct explanation of A
3. CBoth A and R are correct but R is not the correct explanation of A
4. DA is correct but R is not correct
Answer and explanation in LearnFree account
Question 20 · Hard
Read these statements about tubular function. A. The descending limb of Henle's loop is permeable to water but almost impermeable to electrolytes. B. The proximal convoluted tubule reabsorbs only about 20-30 per cent of the electrolytes and water of the filtrate. C. The distal convoluted tubule can reabsorb HCO₃⁻ and selectively secrete H⁺, K⁺ and NH₃. D. The collecting duct allows small amounts of urea to pass into the medullary interstitium. Which of these are correct?
1. AA, B, C and D
2. BC and D only
3. CA, C and D only
4. DA and C only
Answer and explanation in LearnFree account
Question 21 · Hard
Consider these statements about the human kidney: A. Each kidney has nearly one million nephrons. B. Cortical nephrons have long loops of Henle that run deep into the medulla. C. The cortex extends between the medullary pyramids as renal columns called columns of Bertini. D. The vasa recta is absent or highly reduced in cortical nephrons. Which of these are correct?
1. AA, B and C only
2. BB and D only
3. CA, C and D only
4. DA, B, C and D
Answer and explanation in LearnFree account
Question 22 · Easy
In a human nephron, the Malpighian corpuscle, the PCT and the DCT all lie in which region of the kidney?
1. AMedullary pyramids
2. BCortex
3. CRenal pelvis
4. DMedulla
Answer and explanation in LearnFree account
Question 23 · Medium
According to NCERT, the blood filtered by the kidneys each minute is roughly one-fifth of the blood pumped out by each ventricle in a minute. If each ventricle of a person pumps 5.5 L per minute, about how much blood is filtered by the kidneys per minute?
1. A550 mL
2. B1375 mL
3. C1100 mL
4. D125 mL
Answer and explanation in LearnFree account
Question 24 · Hard
In a person who is conserving water, the filtrate is compared with blood plasma at three points: (P) the hairpin bend of Henle's loop in a juxtamedullary nephron, (Q) the end of the ascending limb, (R) the end of the collecting duct. Which description is correct?
1. AP hypotonic, Q hypertonic, R hypotonic
2. BP hypertonic, Q isotonic, R isotonic
3. CP isotonic, Q hypotonic, R hypertonic
4. DP hypertonic, Q hypotonic, R hypertonic
Answer and explanation in LearnFree account
Question 25 · Medium
Given below are two statements: Statement I: Besides reabsorption, the proximal convoluted tubule helps maintain the pH and ionic balance of body fluids by secreting H⁺, NH₃ and K⁺ into the filtrate and absorbing HCO₃⁻ from it. Statement II: The collecting duct allows passage of small amounts of urea into the medullary interstitium to keep up its osmolarity. Choose the correct answer.
1. AStatement I is incorrect but Statement II is correct
2. BStatement I is correct but Statement II is incorrect
3. CBoth Statement I and Statement II are incorrect
4. DBoth Statement I and Statement II are correct
Answer and explanation in LearnFree account

4 more Excretory Products and their Elimination questions

Answer them one by one, keep your score and see your weak topics in Learn. Signed-out visitors try 25 per exam; sign in with Google to see them all.

Study Zoology

Excretory Products and their Elimination

In haemodialysis, the dialysing fluid has the same composition as plasma except that it lacks

A fall in glomerular blood pressure sets off a hormonal cascade. Which substance in this cascade both constricts blood vessels and activates the adrenal cortex to release aldosterone?

A student compares sections of different nephron segments under a microscope. Which segment has a simple cuboidal brush border epithelium that enlarges the surface for reabsorption?

A healthy adult has a glomerular filtration rate of 125 mL per minute. What volume of filtrate do the kidneys form in 24 hours?

A hypothetical drug stops electrolyte transport out of the ascending limb of Henle's loop, while every other segment works normally. Which early effect on urine is expected?

Given below are two statements about the pathway in the figure: Statement I: P is an enzyme released by the JG cells, and Q is angiotensin I. Statement II: R comes from the adrenal medulla and increases the loss of Na⁺ and water in urine. Choose the correct answer.

Osmolarity of the fluid is plotted along a human renal tubule, from Bowman's capsule to the collecting duct. Which marked segment is impermeable to water but allows electrolytes to leave the tubule?

In most human nephrons, the loop of Henle is short and dips only a little into the medulla. These nephrons are called

An increase in blood flow to the atria of the heart causes the release of a factor that

A person's glomerular filtration rate is 120 mL per minute, and 99 per cent of the filtrate is reabsorbed by the tubules. How much urine is formed in one hour?

Arrange these parts of a nephron in the order in which the filtrate flows through them. A. Distal convoluted tubule B. Bowman's capsule C. Henle's loop D. Proximal convoluted tubule

The initial glomerular filtrate has an osmolarity of about 300 mOsmol L⁻¹, and human kidneys can produce urine nearly four times as concentrated as this filtrate. What is the approximate osmolarity of the most concentrated urine?

When the urinary bladder fills, stretch receptors in its wall send signals to the CNS. Which motor response then brings about micturition?

Assertion A: Adaptation to life on land favoured the excretion of less toxic nitrogenous wastes such as urea and uric acid. Reason R: Ammonia, being highly toxic, needs a large amount of water for its elimination. Choose the correct answer.

In a human nephron, the Malpighian corpuscle, the PCT and the DCT all lie in which region of the kidney?

According to NCERT, the blood filtered by the kidneys each minute is roughly one-fifth of the blood pumped out by each ventricle in a minute. If each ventricle of a person pumps 5.5 L per minute, about how much blood is filtered by the kidneys per minute?

In a person who is conserving water, the filtrate is compared with blood plasma at three points: (P) the hairpin bend of Henle's loop in a juxtamedullary nephron, (Q) the end of the ascending limb, (R) the end of the collecting duct. Which description is correct?