75 practice questions on Excretory Products and their Elimination , sorted Easy → Hard. Try each one first, then open its answer page for the worked explanation. Want the full theory first? Read the Excretory Products and their Elimination notes .
The Nephron: Stages of Urine Formation Bowman's capsule FILTRATION PCT bulk REABSORPTION Loop of Henle counter-current - concentrates medulla DCT SECRETION Collecting duct ADH acts HERE Filtrate flows through four functionally distinct stages of the nephron: Bowman's capsule filters blood, the PCT reabsorbs most useful substances unconditionally, the Loop of Henle builds a concentration gradient via counter-current exchange, the DCT secretes selected substances, and the collecting duct performs the final ADH-controlled water reabsorption.
Easy - 25 questions Q2.
The approximate number of nephrons in each human kidney is:
A One thousandB One millionC One hundredD Just tenShow answer & explanation →
Q3.
The nitrogenous waste that needs the least water for its removal is:
A AmmoniaB UreaC Uric acidD Amino acidShow answer & explanation →
Q4.
Blood is brought into the glomerulus by the:
A Renal veinB Efferent arterioleC Peritubular veinD Afferent arterioleShow answer & explanation →
Q5.
Besides the glomerulus, the second capillary bed around a nephron is the:
A Peritubular capillariesB Pulmonary capillariesC Hepatic sinusoidsD Lymphatic capillariesShow answer & explanation →
Q8.
Urine is produced in the kidneys and flows to the bladder via:
A UrethraB UreterC Renal veinD Fallopian tubeShow answer & explanation →
Q10.
Which structure in the nephron is mainly responsible for filtering blood to form the initial filtrate?
A Collecting ductB GlomerulusC Loop of HenleD Distal convoluted tubuleShow answer & explanation →
Q11.
Animals that excrete ammonia as their main nitrogenous waste are called:
A UricotelicB AminotelicC UreotelicD AmmonotelicShow answer & explanation →
Q13.
Which of these is a paired excretory organ in humans, located on either side of the vertebral column?
A LiverB Urinary bladderC KidneyD PancreasShow answer & explanation →
Q14.
The process by which useful substances like glucose are taken back from the filtrate into the blood in the nephron is called:
A MicturitionB ReabsorptionC SecretionD FiltrationShow answer & explanation →
Q15.
The expulsion of urine from the urinary bladder is known as:
A OsmoregulationB MicturitionC UltrafiltrationD FiltrationShow answer & explanation →
Q16.
The removal of nitrogenous and other metabolic wastes from the body is called:
A excretionB digestionC respirationD circulationShow answer & explanation →
Q21.
The tube that carries urine from each kidney to the urinary bladder is the:
A ureterB urethraC oesophagusD tracheaShow answer & explanation →
Q22.
Urine is stored temporarily in the:
A the urinary bladderB the kidney cortexC the liver lobeD the stomach wallShow answer & explanation →
Medium - 25 questions Q26.
The volume of glomerular filtrate formed by the human kidneys per day is about:
A About 1.5 litresB About 180 litresC About 10 litresD About 500 litresShow answer & explanation →
Q27.
Of the filtrate formed daily, the amount finally passed out as urine is about:
A About 90 litresB About 45 litresC About 1.5 litresD About 18 litresShow answer & explanation →
Q28.
Aldosterone from the adrenal cortex makes the kidney reabsorb more:
A Glucose onlyB Urea onlyC Water onlyD Sodium ionsShow answer & explanation →
Q29.
Amoeba and other simple animals remove ammonia from the body mainly by:
A Simple diffusionB Active dialysisC Pressure filtrationD MicturitionShow answer & explanation →
Q30.
Land animals conserve water by excreting nitrogen as urea or as:
A AmmoniaB Uric acidC NitrateD Free nitrogenShow answer & explanation →
Q31.
Glomerular filtration rate (GFR) refers to:
A Volume of urine excreted from the bladder per hourB Volume of blood filtered by glomeruli per minute (normal ~125 mL/min)C Rate at which sodium and water are reabsorbed in the proximal tubuleD Concentration of glucose spilling into urine during hyperglycemiaShow answer & explanation →
Q32.
Antidiuretic hormone (ADH) acts on the:
A Glomerulus to increase the overall rate of filtrationB Collecting duct to increase water reabsorptionC Loop of Henle specifically, bypassing the collecting ductD Urinary bladder directly, increasing its muscular toneShow answer & explanation →
Q33.
Reabsorption of glucose and amino acids from the filtrate occurs mainly in the:
A Distal convoluted tubuleB Loop of HenleC Collecting ductD Proximal convoluted tubuleShow answer & explanation →
Q34.
The process of tubular secretion in the nephron mainly helps to:
A Filter plasma proteins out of the blood at Bowman's capsule in general clinical practiceB Maintain ionic and acid-base balance by adding H+ and K+ to the filtrateC Concentrate filtrate as it enters Bowman's capsule in most reference accountsD Reabsorb filtered glucose back into the peritubular blood as frequently documentedShow answer & explanation →
Q36.
Animals that excrete nitrogenous waste mainly as uric acid are called:
A AmmonotelicB AminotelicC UreotelicD UricotelicShow answer & explanation →
Q37.
The high osmolarity in the medullary interstitium of the kidney is mainly maintained by the:
A Counter-current flow in the loop of Henle and vasa rectaB Renal artery and renal vein together in typical laboratory settingsC Proximal convoluted tubule reabsorbing salts as generally observedD Glomerulus and Bowman's capsule together under normal conditionsShow answer & explanation →
Q38.
A decrease in blood pressure or blood volume stimulates the release of which hormone to help restore them?
A AldosteroneB InsulinC Atrial natriuretic factorD CalcitoninShow answer & explanation →
Q39.
Compared to the glomerular filtrate, the urine that finally leaves the body is much more concentrated mainly because of:
A Reabsorption of most filtered water along the tubules and collecting ductB Secretion of extra water into the filtrate by the tubules according to most studiesC Filtration of plasma proteins at the glomerulus under usual circumstancesD A rise in glomerular filtration rate during the day in the majority of documented casesShow answer & explanation →
Q40.
Atrial Natriuretic Factor (ANF) is released by the heart in response to:
A Low sodium concentration in the blood under most conditions studiedB Increased blood volume stretching the atrial wallC A drop in overall blood volume as widely reportedD A drop in systemic blood pressure in standard reference materialShow answer & explanation →
Q41.
The knot of capillaries in the nephron where blood is filtered is the:
A glomerulusB the alveolusC the villusD the neuronShow answer & explanation →
Q43.
The filtration of blood in the glomerulus under pressure is called:
A ultrafiltrationB digestionC respirationD emulsificationShow answer & explanation →
Q44.
Useful substances such as glucose are taken back into the blood from the nephron by:
A reabsorptionB only filtrationC excretionD secretionShow answer & explanation →
Q45.
Animals that excrete urea as their main nitrogenous waste are said to be:
A ureotelicB uricotelicC ammonotelicD aminotelicShow answer & explanation →
Q46.
Animals such as birds that excrete uric acid are described as:
A uricotelicB ureotelicC ammonotelicD aminotelicShow answer & explanation →
Q48.
The cup-shaped structure that surrounds the glomerulus is the:
A Bowman's capsuleB the loop of HenleC the collecting ductD the ureterShow answer & explanation →
Q49.
The kidneys help to regulate the body’s ___ balance:
A water and saltB oxygen levelC protein levelD fat contentShow answer & explanation →
Q50.
The artificial technique used to filter the blood when the kidneys fail is:
A dialysisB transfusionC only transplantD emulsificationShow answer & explanation →
Hard - 25 questions Q51.
The vasa recta, running alongside the loop of Henle, help hold the medullary gradient by acting as a:
A Simple blood filterB A hollow storage sacC Counter-current exchangerD Secretory glandShow answer & explanation →
Q52.
During tubular secretion, ions such as H<sup>+</sup> and K<sup>+</sup> are added to the filtrate mainly to maintain the blood's:
A Body temperatureB Glucose levelC Red-cell countD Acid-base balanceShow answer & explanation →
Q53.
Glucose appears in the urine (glycosuria) when the blood glucose rises above the tubule's:
A Renal thresholdB Filtration pressureC Osmotic limitD Storage capacityShow answer & explanation →
Q54.
Marine bony fishes tend to lose water osmotically, so they drink seawater and excrete excess salt through the:
A The skin onlyB The gillsC The lungsD A large urine volumeShow answer & explanation →
Q55.
In the urea cycle, urea is formed by combining ammonia with:
A Oxygen gasB Glucose sugarC Carbon dioxideD Lactic acidShow answer & explanation →
Q56.
The juxtaglomerular apparatus (JGA) controls blood pressure by:
A Increasing the filtration surface area of glomerular capillaries on demand quickly in many documented casesB Macula densa sensing tubular flow and releasing renin from JG cells when blood pressure drops (RAAS activation)C Synthesizing aldosterone directly within the nephron for rapid sodium retention purposes according to conventional understandingD Selectively blocking the passage of plasma proteins across Bowman's capsule membrane in routine practice overallShow answer & explanation →
Q57.
The counter-current multiplier in the loop of Henle:
A It filters plasma proteins out of the blood as it enters the glomerulus using size-selective podocyte slits rather than any salt-gradient mechanism in the medullaB Creates a hyperosmotic medullary gradient by active NaCl transport in thick ascending limb, enabling concentrated urine productionC It reabsorbs all filtered glucose completely via SGLT transporters in the descending limb, a transporter and nephron segment actually responsible for glucose, not osmotic gradient formationD It synthesizes and releases the enzyme renin into the afferent arteriole, a hormone-secreting function carried out by granular cells, not the loop of Henle itselfShow answer & explanation →
Q58.
The renin-angiotensin-aldosterone system (RAAS) chain is:
A Renin cleaves angiotensinogen to Ang I, ACE converts to Ang II, Ang II stimulates aldosterone secretion from adrenal cortexB Renin is converted directly into aldosterone by hepatic liver enzymes without any intermediate steps under most conditions encounteredC Aldosterone secreted by the adrenal cortex stimulates juxtaglomerular cells to release more renin as frequently observed in practiceD ACE inhibitors bind angiotensin II receptors directly to amplify overall RAAS signaling activity in many documented casesShow answer & explanation →
Q59.
Aquaporin-2 channels in collecting duct are regulated by:
A ADH binding directly to the AQP2 channel pore to physically widen its overall diameter according to conventional understandingB ADH-stimulated PKA phosphorylation of AQP2, causing vesicle fusion with apical membrane (more water channels inserted)C Aldosterone-driven upregulation of sodium channels located on the basolateral membrane surface in routine practiceD Renin-mediated cleavage of angiotensinogen occurring within the collecting duct lumen region overall in most casesShow answer & explanation →
Q60.
ADH (vasopressin) acts on the kidney to conserve water mainly by:
A Stimulating renin release from nearby juxtaglomerular cellsB Raising glomerular filtration rate to filter more blood plasmaC Raising water permeability of the distal tubule and collecting ductD Blocking sodium reabsorption within the proximal tubuleShow answer & explanation →
Q61.
The descending limb of the loop of Henle is relatively impermeable to which substance, a key feature of the counter-current mechanism?
A Glucose dissolved in the filtrateB WaterC Urea, but not other ionsD Sodium and chloride ionsShow answer & explanation →
Q62.
If the afferent arteriole of a glomerulus constricts, the most direct effect on kidney function would be:
A A rise in glomerular filtration rate from higher blood flowB No change, since arteriole diameter does not affect filtrationC A surge of glucose being secreted directly into urineD A fall in glomerular filtration rate from reduced blood flowShow answer & explanation →
Q63.
Urea recycling between the collecting duct and the loop of Henle contributes to the kidney's concentrating ability mainly by:
A Adding to medullary osmolarity, which aids water reabsorption from the ductB Reducing sodium reabsorption mainly along the nephronC Pumping water out of the collecting duct without any osmotic gradientD Diluting the medullary interstitium to limit water lossShow answer & explanation →
Q64.
In uremia, a condition associated with kidney failure, urea accumulates in the blood mainly because:
A The liver has stopped producing urea from ammoniaB The urinary bladder fails to store urine properlyC Urea is being overproduced by the pancreas insteadD The kidneys cannot filter and excrete urea efficientlyShow answer & explanation →
Q65.
During hemodialysis, a patient's blood is passed through a dialysing fluid that has a composition similar to plasma but lacking nitrogenous wastes, mainly so that:
A Red blood cells pass freely into the dialysing fluid in most observed casesB Nitrogenous wastes diffuse out down their gradient while useful solutes stayC Plasma proteins diffuse out of the blood into the fluid in standard reference materialD Water is pumped into the blood from the dialysing fluid under most conditions studiedShow answer & explanation →
Q66.
The region of the nephron where most reabsorption of water and nutrients occurs is the:
A proximal convoluted tubuleB the glomerulus knotC the long collecting ductD the Bowman's capsule cupShow answer & explanation →
Q67.
The hormone that controls water reabsorption in the kidney is:
A ADH (vasopressin)B the hormone insulinC plain adrenalineD plain thyroxineShow answer & explanation →
Q68.
The loop-shaped part of the nephron that helps concentrate the urine is the:
A loop of HenleB glomerulusC Bowman's capsuleD ureterShow answer & explanation →
Q69.
Ammonia is the most toxic nitrogenous waste and its excretion needs:
A a large amount of waterB very little waterC no water at allD only a moderate amountShow answer & explanation →
Q70.
Excreting nitrogen as uric acid, as birds and reptiles do, mainly helps them to conserve:
A waterB energyC proteinD oxygenShow answer & explanation →
Q71.
The kidney’s role in maintaining the water and ionic balance of body fluids is called:
A osmoregulationB respirationC digestionD circulationShow answer & explanation →
Q72.
The excretory structures found in insects are the:
A Malpighian tubulesB the kidney nephronsC simple flame cellsD simple sweat glandsShow answer & explanation →
Q73.
Glucose normally does not appear in the urine of a healthy person because it is completely:
A reabsorbedB filtered outC secretedD digestedShow answer & explanation →
Q75.
Flame cells serve as the excretory structures in:
A flatworms such as PlanariaB human beings like usC birds and their kinD various common insectsShow answer & explanation →