Excretory Products and Their Elimination — Class 11 MCQs with Answers
Class 11 CBSE Biology · Chapter 16
90 practice questions · 30 Easy · 30 Medium · 30 Hard · Updated
Practise the most important Class 11 CBSE Biology questions from Chapter 16, "Excretory Products and Their Elimination". You get 9 timed quizzes made from 90 NCERT-based MCQs, with answers and explanations. The questions are split into 30 Easy, 30 Medium and 30 Hard. Warm up on the basics, then move on to the exam-level questions that set top scorers in CBSE & Maharashtra HSC Board exams, MHT-CET and NEET UG apart.
To score well in "Excretory Products and Their Elimination", focus on diagrams, key terms and knowing NCERT line by line. Each MCQ here is timed and uses exam-style marking (+4 correct, −1 wrong, 0 skipped). This trains you to stay accurate under time pressure, as real papers need. Every question has a short explanation, so a wrong answer becomes a quick lesson. It is the fastest way to fix gaps before a test.
Use this chapter for focused revision. Start with the Easy set to check your basics on Excretory Products and Their Elimination, then move to Medium and Hard to practise applying them. Your accuracy, streaks and XP save automatically. This chapter also adds to your overall Class 11 Biology mastery score. 14 sample questions are solved in full below, with the answer and a worked explanation. Sign in free to start practising.
Key concepts: Excretory Products and Their Elimination (Class 11 Biology)
Nitrogenous wastes must be voided without losing too much water. This chapter compares ammonotelism, ureotelism and uricotelism, dissects the nephron, and follows urine formation through filtration, reabsorption and secretion, the counter-current multiplier that concentrates urine, hormonal control, and dialysis.
- Modes of excretion
- Animals are ammonotelic (ammonia, aquatic), ureotelic (urea, mammals) or uricotelic (uric acid, birds and reptiles) by water availability and toxicity.
- Human excretory system
- Two kidneys, two ureters, a urinary bladder and the urethra; each kidney has an outer cortex, an inner medulla with pyramids, and a pelvis.
- Nephron
- The nephron is the functional unit: a glomerulus in Bowman's capsule (Malpighian body), proximal tubule, loop of Henle, distal tubule and collecting duct.
- Cortical vs juxtamedullary
- Cortical nephrons have short loops barely entering the medulla; juxtamedullary nephrons have long loops with vasa recta, key to concentrating urine.
Excretory Products and Their Elimination — important questions & MCQs with answers (Class 11 Biology)
14 solved questions from this chapter's difficulty levels, each with its answer and explanation. The other 76 are timed and scored when you sign in.
- Q1Easy
Functional unit of kidney:
A.Nephron✓ CorrectB.NeuronC.AlveolusD.HepatocyteAnswer: A. Nephron
Explanation: The nephron filters, reabsorbs and secretes to form urine — the name sounds like neuron but that's the nerve cell's unit, and alveolus belongs to the lung.
- Q2Easy
Animals that excrete mainly ammonia are termed:
A.UreotelicB.Ammonotelic✓ CorrectC.UricotelicD.AminotelicAnswer: B. Ammonotelic
Explanation: Ammonotelic animals excrete nitrogen mainly as ammonia, the most toxic form but cheapest to make. It needs plenty of water to dilute, so it suits aquatic animals like bony fishes.
- Q3Easy
Which hormone increases water reabsorption from collecting duct?
A.AldosteroneB.ADH✓ CorrectC.ANFD.ReninAnswer: B. ADH
Explanation: ADH (vasopressin) raises water reabsorption in the collecting duct via aquaporin channels; aldosterone instead targets Na+ reabsorption in the DCT.
- Q4Easy
Humans are:
A.UricotelicB.AmmonotelicC.Ureotelic✓ CorrectD.NoneAnswer: C. Ureotelic
Explanation: Humans are ureotelic: liver converts toxic ammonia to less-toxic urea via the ornithine cycle. Aquatic animals stay ammonotelic; birds/reptiles are uricotelic to save water.
- Q5Easy
Birds and reptiles primarily excrete:
A.Uric acid✓ CorrectB.UreaC.AmmoniaD.CreatinineAnswer: A. Uric acid
Explanation: Birds and reptiles are uricotelic, excreting semi-solid uric acid that needs almost no water — key for animals that can't afford to lose fluid, unlike ureotelic mammals.
- Q6Easy
Aldosterone primarily promotes reabsorption of:
A.Water in collecting ductB.Glucose in PCTC.Na⁺ in DCT✓ CorrectD.Urea in loop of HenleAnswer: C. Na⁺ in DCT
Explanation: Aldosterone from the adrenal cortex promotes Na+ reabsorption (and K+ secretion) in the DCT — distinct from ADH, which targets water in the collecting duct.
- Q7Medium
Glomerular filtration occurs in:
A.Bowman's capsule✓ CorrectB.Loop of HenleC.Collecting ductD.BladderAnswer: A. Bowman's capsule
Explanation: Glomerular filtration happens in Bowman's capsule, where blood pressure forces plasma past the glomerulus wall. The loop of Henle and collecting duct concentrate urine afterward, they don't filter it.
- Q8Medium
Urea is synthesised in liver through:
A.Calvin cycleB.Krebs cycleC.Glyoxylate cycleD.Ornithine cycle✓ CorrectAnswer: D. Ornithine cycle
Explanation: The liver makes urea from ammonia and CO2 via the ornithine (urea) cycle, not the Krebs or Calvin cycle, which handle respiration and photosynthesis instead.
- Q9Medium
ADH (vasopressin) acts on:
A.Liver onlyB.HeartC.LungsD.Collecting duct — increases water reabsorption✓ CorrectAnswer: D. Collecting duct — increases water reabsorption
Explanation: ADH acts on the collecting duct, inserting aquaporin channels so water is reabsorbed and urine concentrates. It doesn't touch the liver, heart or lungs directly.
- Q10Medium
Renal cortex projects into medulla in the form of:
A.Pyramids of MalpighiB.Loops of HenleC.Columns of Bertini✓ CorrectD.Vasa rectaAnswer: C. Columns of Bertini
Explanation: Renal cortex tissue dips between medullary pyramids as the columns of Bertini, distinct from the pyramids themselves or the loops of Henle within them.
- Q11Medium
Adult frog living on land is:
A.AmmonotelicB.Ureotelic✓ CorrectC.UricotelicD.AminotelicAnswer: B. Ureotelic
Explanation: Adult frogs on land are ureotelic like humans; only their aquatic tadpole stage is ammonotelic, switching to urea as they metamorphose and leave water.
- Q12Hard
Haemodialysis uses:
A.HeatB.MagnetismC.LightD.Artificial semipermeable membrane to remove wastes✓ CorrectAnswer: D. Artificial semipermeable membrane to remove wastes
Explanation: Haemodialysis passes blood across an artificial semipermeable membrane against dialysing fluid, removing urea and wastes when nephrons fail — no heat, magnetism or light involved.
- Q13Hard
Excretion as uric acid involves:
A.Less ATP and more waterB.More ATP expenditure but less water loss✓ CorrectC.No ATP and most water lossD.Only passive processAnswer: B. More ATP expenditure but less water loss
Explanation: Making uric acid costs more ATP than urea or ammonia synthesis, but its near-insolubility means excretion loses far less water — an energy-for-water trade-off.
- Q14Hard
Renin is released by kidney to regulate:
A.Blood pressure (RAAS)✓ CorrectB.Body temperatureC.VisionD.Bone densityAnswer: A. Blood pressure (RAAS)
Explanation: Renin, released by juxtaglomerular cells when blood pressure or GFR falls, triggers the RAAS to raise blood pressure — not temperature, vision or bone density.
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Start this chapter free →Excretory Products and Their Elimination — FAQs
What are the key concepts in Class 11 Biology Excretory Products and Their Elimination?+
Nitrogenous wastes must be voided without losing too much water. This chapter compares ammonotelism, ureotelism and uricotelism, dissects the nephron, and follows urine formation through filtration, reabsorption and secretion, the counter-current multiplier that concentrates urine, hormonal control, and dialysis. Key ideas include Modes of excretion, Human excretory system, Nephron, Cortical vs juxtamedullary.
What does Class 11 Biology Chapter 16 (Excretory Products and Their Elimination) cover on XamBaaz?+
It has 90 NCERT-based MCQs on "Excretory Products and Their Elimination": 30 Easy, 30 Medium and 30 Hard. Together they make 9 timed quizzes, and you never get the same set twice. Every question has an instant explanation. They help you prepare for CBSE & Maharashtra HSC Board exams, MHT-CET and NEET UG.
Are these "Excretory Products and Their Elimination" questions free to practise?+
Yes. Sign in with Google to practise "Excretory Products and Their Elimination" free. Full unlimited access is ₹999/year on a launch offer until 1 December 2026. No chapter is charged separately.
How should I revise "Excretory Products and Their Elimination" for the exam?+
Start with the Easy quiz to check your basics, then try Medium and Hard to practise applying them. There are 9 timed quizzes on this chapter, so you can come back for a fresh set instead of one you have seen. Read each explanation, retry the questions you miss, and track your accuracy until it stays high.
Are these "Excretory Products and Their Elimination" MCQs available with answers?+
Yes. 14 sample questions are shown here in full, each with the correct option and a step-by-step "Why" explanation. Sign in free with Google to start practising, with instant scoring.
Is there negative marking in the "Excretory Products and Their Elimination" quizzes?+
Yes. The timed quizzes use exam-style marking: +4 for a right answer, −1 for a wrong one and 0 for a skip, the same negative marking as NEET UG. MHT-CET and CBSE board papers have no negative marking. Our mocks for those are scored their way.
What are the important questions from Excretory Products and Their Elimination (Class 11 Biology)?+
The questions that matter most test Modes of excretion, Human excretory system, Nephron, Cortical vs juxtamedullary. This page shows 14 solved important MCQs with answers and explanations; all 90 questions on the chapter are available as timed quizzes once you sign in.
Is there an online quiz for Excretory Products and Their Elimination?+
Yes — Class 11 Biology Excretory Products and Their Elimination has timed online quizzes at Easy, Medium and Hard levels, with instant scoring and a worked explanation on every question. The first quiz on the chapter is free.