Excretory Products and Their Elimination — Page 4 | NEET Biology

Q31

Which one of the following statements is correct with respect to kidney function regulation?

A When someone drinks lot of water, ADH release is suppressed.

B Exposure to cold temperature stimulates formation of Angiotensin II.

C An increase in glomerular blood flow stimulates formation of Angiotensin II.

D During summer when body loses lot of water by evaporation, the release of ADH is suppressed.

Correct Answer

Option A

Solution

(a) When someone drinks lots of water, ADH release is suppressed, producing more dilute urine.

Q32

Which one of the following correctly explains the function of a specific part of a human nephron?

A Podocytes create minute spaces (slit pores) for filtration of blood into Bowman's capsule

B Henle's loop: most reabsorption of water and ions from glomerular filtrate

C Distal convoluted tubule: reabsorption of K+ ions into surrounding blood capillaries

D Afferent arteriole: carries blood towards renal vein.

Correct Answer

Option A

Solution

(a) Podocytes have slit pores that form the filtration barrier in the glomerular capsule.

Q33

Which one of the following characteristics is common to both humans and adult frogs?

A Four-chambered heart

B Internal fertilization

C Nucleated RBCs

D Ureotelic mode of excretion

Correct Answer

Option D

Solution

(d) Both adult frogs and humans are ureotelic — they excrete urea as nitrogenous waste.

Q34

A fall in glomerular filtration rate (GFR) activates

A adrenal cortex to release aldosterone.

B adrenal medulla to release adrenaline.

C juxta-glomerular cells to release renin.

D posterior pituitary to release vasopressin.

Correct Answer

Option C

Solution

(c) Fall in GFR activates JG cells to release renin → angiotensin II → increased GFR.

Q35

The maximum amount of electrolytes and water (70-80%) from the glomerular filtrate is reabsorbed in which part of the nephron?

A Ascending limb of loop of Henle

B Distal convoluted tubule

C Proximal convoluted tubule

D Descending limb of loop of Henle

Correct Answer

Option C

Solution

(c) PCT reabsorbs nearly all essential nutrients and 70-80% of electrolytes and water.

Q36

Which of the following causes an increase in sodium reabsorption in the distal convoluted tubule?

A Increase in aldosterone levels

B Increase in antidiuretic hormone levels

C Decrease in aldosterone levels

D Decrease in antidiuretic hormone levels

Correct Answer

Option A

Solution

(a) Aldosterone increases reabsorption of sodium and water in DCT, increasing blood pressure.

Q37

Human urine is usually acidic because:

A excreted plasma proteins are acidic

B potassium and sodium exchange generates acidity

C hydrogen ions are actively secreted into the filtrate.

D the sodium transporter exchanges one hydrogen ion for each sodium ion in peritubular capillaries.

Correct Answer

Option C

Solution

(c) Hydrogen ions (H+) are actively secreted into the filtrate, making urine acidic.

Q38

Removal of proximal convoluted tubule from the nephron will result in:

A More concentrated urine

B No change in quality and quantity of urine

C No urine formation

D More diluted urine

Correct Answer

Option D

Solution

(d) PCT reabsorbs 70-80% of electrolytes and water; its removal leads to more dilute urine.

Q39

Which of the following does not favour the formation of large quantities of dilute urine?

A Caffeine

B Renin

C Atrial-natriuretic factor

D Alcohol

Correct Answer

Option B

Solution

(b) Renin maintains blood pressure; it has no role in forming large quantities of dilute urine.

Q40

In mammals, which blood vessel would normally carry largest amount of urea?

A Renal Vein

B Dorsal Aorta

C Hepatic Vein

D Hepatic Portal Vein

Correct Answer

Option C

Solution

(c) Hepatic vein carries the most urea because the liver produces urea via the ornithine cycle.