Chapter 19: Excretory Products and Their Elimination – MCQs with Answers & Explanations

CBSE Class 11 Biology MCQs – Excretory Products and Their Elimination (NCERT-Based)

Course & Examination Details

• Course: CBSE Class 11 Biology
• Prescribed By: Central Board of Secondary Education
• Based On: NCERT
• Unit: Unit V – Human Physiology
• Chapter: Chapter 19 – Excretory Products and Their Elimination
• Question Type: Multiple Choice Questions (MCQs)
• Exam Relevance: CBSE Class 11 Annual Exam, Unit Tests, Periodic Assessments

Section A: Excretory System (MCQ 1–18)

1. Excretion is defined as the removal of

A. Undigested food
B. Metabolic wastes
C. Excess nutrients
D. Hormones

Correct Answer: B
Explanation:
Excretion involves removal of metabolic wastes like urea, excess salts, and water produced during metabolism.

2. Humans are classified as ureotelic because they excrete nitrogen mainly as

A. Ammonia
B. Uric acid
C. Creatinine
D. Urea

Correct Answer: D
Explanation:
Urea is the chief nitrogenous waste excreted by humans.

3. The main excretory organs in humans are

A. Lungs
B. Liver
C. Kidneys
D. Skin

Correct Answer: C
Explanation:
Kidneys filter blood and remove nitrogenous wastes through urine.

4. The functional unit of kidney is

A. Neuron
B. Alveolus
C. Nephron
D. Glomerulus

Correct Answer: C
Explanation:
Nephrons are structural and functional units responsible for urine formation.

5. Each human kidney contains approximately

A. 10,000 nephrons
B. 100,000 nephrons
C. 1 million nephrons
D. 10 million nephrons

Correct Answer: C
Explanation:
Each kidney has about one million nephrons.

6. The cup-shaped structure enclosing the glomerulus is

A. Renal pelvis
B. Bowman’s capsule
C. Loop of Henle
D. Collecting duct

Correct Answer: B
Explanation:
Bowman’s capsule surrounds the glomerulus and collects filtrate.

7. Blood enters the glomerulus through

A. Renal vein
B. Efferent arteriole
C. Afferent arteriole
D. Vasa recta

Correct Answer: C
Explanation:
Afferent arteriole brings blood into the glomerulus.

8. Which nephron type is mainly involved in urine concentration?

A. Cortical nephron
B. Juxtamedullary nephron
C. Malpighian body
D. Renal corpuscle

Correct Answer: B
Explanation:
Juxtamedullary nephrons have long loops of Henle essential for urine concentration.

9. The funnel-shaped cavity in kidney leading to ureter is

A. Renal cortex
B. Renal medulla
C. Renal pelvis
D. Collecting duct

Correct Answer: C
Explanation:
Renal pelvis collects urine and directs it into ureter.

10. The right kidney is placed slightly lower because of the presence of

A. Heart
B. Lungs
C. Liver
D. Spleen

Correct Answer: C
Explanation:
The liver occupies space above the right kidney.

11. Which organ converts ammonia into urea?

A. Kidney
B. Liver
C. Lung
D. Skin

Correct Answer: B
Explanation:
The liver converts toxic ammonia into urea.

12. Lungs act as excretory organs by removing

A. Urea
B. Ammonia
C. Carbon dioxide
D. Creatinine

Correct Answer: C
Explanation:
Lungs excrete carbon dioxide and water vapour.

13. Sweat excreted by skin contains

A. Urea only
B. Salts only
C. Water, salts, and urea
D. Glucose

Correct Answer: C
Explanation:
Sweat contains water, salts, and traces of urea.

14. Renal calculi are formed due to

A. Infection
B. Protein deficiency
C. Salt precipitation
D. Excess water intake

Correct Answer: C
Explanation:
Kidney stones form due to precipitation of salts like calcium oxalate.

15. Uremia refers to

A. Blood infection
B. High glucose in blood
C. Accumulation of urea in blood
D. Kidney stone formation

Correct Answer: C
Explanation:
Uremia occurs due to kidney failure causing urea buildup in blood.

16. Which of the following is NOT a part of human excretory system?

A. Kidney
B. Ureter
C. Urinary bladder
D. Gall bladder

Correct Answer: D
Explanation:
Gall bladder is part of digestive system, not excretory system.

17. The tube carrying urine from bladder to outside is

A. Ureter
B. Urethra
C. Renal pelvis
D. Nephron

Correct Answer: B
Explanation:
Urethra expels urine from the bladder.

18. Temporary storage of urine occurs in

A. Kidney
B. Ureter
C. Urinary bladder
D. Urethra

Correct Answer: C
Explanation:
Urinary bladder stores urine before micturition.

Section B: Urine Formation (MCQ 19–36)

19. Urine formation begins with

A. Reabsorption
B. Filtration
C. Secretion
D. Osmosis

Correct Answer: B
Explanation:
Glomerular filtration is the first step of urine formation.

20. Glomerular filtration occurs in

A. PCT
B. Loop of Henle
C. DCT
D. Glomerulus

Correct Answer: D
Explanation:
Filtration of blood plasma occurs in glomerulus.

21. The filtrate formed in Bowman’s capsule lacks

A. Water
B. Glucose
C. Proteins
D. Salts

Correct Answer: C
Explanation:
Proteins are too large to pass through filtration membrane.

22. Normal glomerular filtration rate (GFR) is about

A. 50 mL/min
B. 75 mL/min
C. 100 mL/min
D. 125 mL/min

Correct Answer: D
Explanation:
GFR in healthy adults is about 125 mL per minute.

23. Maximum reabsorption occurs in

A. DCT
B. Collecting duct
C. PCT
D. Loop of Henle

Correct Answer: C
Explanation:
PCT reabsorbs glucose, amino acids, ions, and water.

24. Selective reabsorption helps in

A. Waste removal
B. Loss of nutrients
C. Conservation of useful substances
D. Increasing urine volume

Correct Answer: C
Explanation:
Useful substances are reabsorbed into blood.

25. Tubular secretion mainly occurs in

A. Bowman’s capsule
B. PCT
C. DCT
D. Collecting duct

Correct Answer: C
Explanation:
DCT secretes ions like H⁺ and K⁺.

26. Which substance is secreted to regulate pH?

A. Sodium
B. Hydrogen ions
C. Glucose
D. Water

Correct Answer: B
Explanation:
Hydrogen ions regulate blood pH.

27. Loop of Henle helps in

A. Filtration
B. Secretion
C. Concentration of urine
D. Micturition

Correct Answer: C
Explanation:
It establishes osmotic gradient for urine concentration.

28. Descending limb of loop of Henle is permeable to

A. Salts
B. Proteins
C. Water
D. Glucose

Correct Answer: C
Explanation:
Water diffuses out of descending limb.

29. Ascending limb of loop of Henle is impermeable to

A. Salts
B. Water
C. Ions
D. Urea

Correct Answer: B
Explanation:
Ascending limb does not allow water movement.

30. Counter current mechanism operates between

A. PCT and DCT
B. Nephron and bladder
C. Loop of Henle and vasa recta
D. Glomerulus and tubule

Correct Answer: C
Explanation:
These structures maintain osmotic gradient.

31. The final concentration of urine is regulated mainly by

A. Aldosterone
B. Insulin
C. ADH
D. Thyroxine

Correct Answer: C
Explanation:
ADH controls water reabsorption.

32. Dilute urine is formed when

A. ADH increases
B. ADH decreases
C. Aldosterone increases
D. ANF decreases

Correct Answer: B
Explanation:
Low ADH causes reduced water reabsorption.

33. Proteins appear in urine when

A. Blood pressure rises
B. Kidney is damaged
C. Water intake increases
D. ADH secretion increases

Correct Answer: B
Explanation:
Proteinuria indicates glomerular damage.

34. Micturition is

A. Urine formation
B. Urine filtration
C. Urine storage
D. Urine expulsion

Correct Answer: D
Explanation:
Micturition is expulsion of urine.

35. Which substance is normally absent in urine?

A. Urea
B. Uric acid
C. Creatinine
D. Glucose

Correct Answer: D
Explanation:
Glucose is reabsorbed completely in healthy individuals.

36. Diuresis refers to

A. Reduced urine output
B. Increased urine output
C. Kidney inflammation
D. Stone formation

Correct Answer: B
Explanation:
Diuresis is increased urine formation.

Section C: Regulation of Kidney Function (MCQ 37–50)

37. ADH is secreted by

A. Thyroid
B. Adrenal cortex
C. Posterior pituitary
D. Pancreas

Correct Answer: C
Explanation:
ADH is released from posterior pituitary.

38. Aldosterone primarily regulates

A. Water reabsorption
B. Sodium and potassium balance
C. Glucose level
D. Blood pH directly

Correct Answer: B
Explanation:
Aldosterone increases Na⁺ reabsorption and K⁺ excretion.

39. Atrial natriuretic factor (ANF) is released from

A. Kidneys
B. Lungs
C. Heart atria
D. Adrenal gland

Correct Answer: C
Explanation:
ANF reduces blood volume and pressure.

40. Juxtaglomerular apparatus regulates

A. Respiration
B. Digestion
C. Blood pressure and GFR
D. Hormone secretion

Correct Answer: C
Explanation:
JGA controls renal blood flow and filtration.

41. The enzyme released by JGA is

A. Pepsin
B. Renin
C. Trypsin
D. Amylase

Correct Answer: B
Explanation:
Renin regulates blood pressure.

42. Dialysis is needed when

A. Liver fails
B. Lungs fail
C. Kidneys fail
D. Heart fails

Correct Answer: C
Explanation:
Dialysis removes wastes when kidneys fail.

43. Hemodialysis uses a

A. Filter paper
B. Dialyzer
C. Glomerulus
D. Catheter only

Correct Answer: B
Explanation:
Dialyzer acts as artificial kidney.

44. Kidney transplantation requires

A. Antibiotics only
B. Hormone therapy
C. Tissue matching
D. Blood transfusion only

Correct Answer: C
Explanation:
Matching reduces rejection risk.

45. Excess ADH secretion leads to

A. Dilute urine
B. Concentrated urine
C. No urine
D. Kidney stones

Correct Answer: B
Explanation:
More water reabsorbed → concentrated urine.

46. Low blood pressure stimulates release of

A. ADH only
B. Insulin
C. Renin
D. ANF

Correct Answer: C
Explanation:
Renin helps raise blood pressure.

47. Which factor directly affects GFR?

A. Blood pressure
B. Blood glucose
C. Oxygen level
D. Body temperature

Correct Answer: A
Explanation:
GFR depends on glomerular blood pressure.

48. Removal of kidney wastes helps maintain

A. Digestion
B. Homeostasis
C. Respiration
D. Movement

Correct Answer: B
Explanation:
Excretion maintains internal balance.

49. Which condition is treated by dialysis?

A. Diabetes
B. Hypertension
C. Renal failure
D. Kidney stones

Correct Answer: C
Explanation:
Dialysis substitutes kidney function.

50. Excretion is essential because accumulation of wastes is

A. Helpful
B. Harmless
C. Toxic
D. Nutritive

Correct Answer: C
Explanation:
Metabolic wastes are toxic to cells.

NCERT & CBSE Compliance Note

✔ Strictly based on NCERT Class 11 Biology
✔ Concept-clearing explanations included
✔ Fully aligned with CBSE exam pattern
✔ Ideal for revision, practice, and assessments

🎯 Targeting Exams

This MCQ set is useful for preparation of:

• CBSE Class 11 Biology Annual Examination

• CBSE Unit Tests & Periodic Assessments

• NEET (UG) – Human Physiology Fundamentals

• CUET (UG) – Biology Section

• State Board Class 11 Biology Exams

• Medical & Paramedical Entrance Foundation Courses

🔑 Related & Semantic Keyphrases

• Excretory Products and Their Elimination MCQs Class 11

• CBSE Class 11 Biology Chapter 19 MCQs

• NCERT Excretory System MCQs

• Human Excretory System MCQs Class 11

• Urine Formation MCQs Class 11 Biology

• Kidney Function MCQs Class 11

• Regulation of Kidney Function MCQs

• NCERT Class 11 Biology Objective Questions