NEET 2025 MCQ with Answer Explanation : “Excretory Products and their Elimination”

MCQ 41
Which structure carries urine from the kidneys to the bladder?

A) Urethra
B) Renal pelvis
C) Ureter
D) Collecting duct

Answer: C) Ureter

Explanation: The ureters are tubes that transport urine from the kidneys to the bladder for storage.

MCQ 42
Which organ is primarily responsible for detoxifying ammonia?

A) Kidney
B) Liver
C) Pancreas
D) Spleen

Answer: B) Liver

Explanation: The liver converts toxic ammonia into urea, which can then be safely excreted by the kidneys.

MCQ 43
Which type of transport is primarily used for glucose reabsorption in the nephron?

A) Passive diffusion
B) Active transport
C) Facilitated diffusion
D) Bulk flow

Answer: B) Active transport

Explanation: Glucose reabsorption in the proximal convoluted tubule occurs via active transport, requiring energy to move glucose against its concentration gradient.

MCQ 44
The term ‘osmolarity’ refers to:

A) Concentration of solids in urine
B) Concentration of solute particles in a solution
C) Volume of urine produced
D) pH level of urine

Answer: B) Concentration of solute particles in a solution

Explanation: Osmolarity measures the total concentration of solute particles in a solution, influencing fluid balance and kidney function.

MCQ 45
What happens to the glomerular filtration rate (GFR) when blood pressure decreases?

A) Increases
B) Decreases
C) Remains constant
D) Fluctuates

Answer: B) Decreases

Explanation: A decrease in blood pressure typically leads to a reduction in GFR, as there is less pressure available to drive filtration.

MCQ 46
What is the primary waste product excreted by the kidneys?

A) Bilirubin
B) Urea
C) Glucose
D) Hormones

Answer: B) Urea

Explanation: Urea, a nitrogenous waste product of protein metabolism, is the primary waste product excreted in urine.

MCQ 47
Which condition is characterized by the presence of excessive protein in urine?

A) Hematuria
B) Proteinuria
C) Oliguria
D) Anuria

Answer: B) Proteinuria

Explanation: Proteinuria refers to the presence of excess protein in the urine, often indicating kidney dysfunction or damage.

MCQ 48
What triggers the release of aldosterone from the adrenal glands?

A) High potassium levels
B) Low sodium levels
C) Low blood pressure
D) All of the above

Answer: D) All of the above

Explanation: Aldosterone release is stimulated by high potassium levels, low sodium levels, and low blood pressure to help regulate electrolyte balance and blood volume.

MCQ 49
Which of the following is an indicator of kidney function in blood tests?

A) Blood urea nitrogen (BUN)
B) Serum creatinine
C) Glucose
D) A and B only

Answer: D) A and B only

Explanation: Blood urea nitrogen (BUN) and serum creatinine are both indicators of kidney function and help assess renal health.

MCQ 50
What is the primary function of the loop of Henle?

A) Filtration
B) Concentration of urine
C) Reabsorption of amino acids
D) Regulation of blood pH

Answer: B) Concentration of urine

Explanation: The loop of Henle creates a concentration gradient that allows for the reabsorption of water and the production of concentrated urine.