Excretion in Humans
Each subtopic includes About section, revision page link, 10 preview questions, and practice CTAs.
Excretory products
SubtopicExcretory products under Excretion in Humans for Grade 11 IGCSE.
Preview questions (no answers)
- 1.
Which of the following is a substance that the body needs to remove to maintain a constant internal environment?
A.Excess salts
B.Glucose for energy
C.Oxygen for respiration
D.Red blood cells for transport
- 2.
What is the function of the urethra?
A.To produce urine
B.To store urine
C.To transport urine out of the body
D.To transport blood to the kidney
- 3.
Which waste product is produced from the breakdown of excess amino acids?
A.Carbon dioxide
B.Water
C.Urea
D.Oxygen
- 4.
In humans, where does the majority of urea excretion occur?
A.Lungs
B.Skin
C.Kidneys
D.Intestines
- 5.
The diagram shows the metabolic and dietary origins of three substances that are removed from the blood and excreted by the kidneys. Which row correctly identifies these three substances?
A.Substance 1: Salts; Substance 2: Water; Substance 3: Urea
B.Substance 1: Urea; Substance 2: Water; Substance 3: Salts
C.Substance 1: Urea; Substance 2: Carbon dioxide; Substance 3: Salts
D.Substance 1: Ammonia; Substance 2: Water; Substance 3: Carbon dioxide
- 6.
Which of these is a metabolic waste product of aerobic respiration?
A.Glucose
B.Nitrogen
C.Water
D.Oxygen
- 7.
Why is the liver considered an accessory organ of the excretory system?
A.It pumps blood to the kidneys
B.It produces the urea that the kidneys excrete
C.It stores urine before it is released
D.It removes carbon dioxide from the blood
- 8.
A person spends a day in a very hot environment and drinks very little water. What change would you expect in their urea excretion?
A.The concentration of urea in the urine will increase, but the total mass of urea excreted remains similar.
B.The total mass of urea excreted will double to compensate for the lack of water.
C.The kidneys will stop excreting urea entirely to conserve water.
D.The urea will be converted back into amino acids to prevent water loss.
- 9.
Which statement about the origin of excretory products is correct?
A.Urea is made in the liver; is made in all living cells; Salts are taken in with food.
B.Urea is made in the kidney; is made in the lungs; Salts are made in the skin.
C.Urea is made in the bladder; is made in the heart; Salts are made in the liver.
D.Urea is made in the muscles; is made in the liver; Salts are made in the blood.
- 10.
If the body's pH begins to drop due to high levels of , how does the excretory system respond to maintain homeostasis?
A.The breathing rate increases to expel more via the lungs.
B.The kidneys secrete more urea to neutralize the acidity.
C.The skin produces more sweat to wash away the excess carbonic acid.
D.The liver converts the excess into glucose to store energy.
Download the worksheet for Excretion in Humans - Excretory products to practice offline. It includes additional chapter-level practice questions.
Structure and function of kidneys
SubtopicStructure and function of kidneys under Excretion in Humans for Grade 11 IGCSE.
Preview questions (no answers)
- 1.
Which component of the nephron comes immediately after the Bowman's capsule?
A.Loop of Henle
B.Collecting duct
C.Proximal convoluted tubule
D.Distal convoluted tubule
- 2.
What is the name for the process where useful substances are taken back into the blood from the kidney tubule?
A.Active filtration
B.Selective reabsorption
C.Osmosis
D.Diffusion
- 3.
Which of these is a metabolic waste product?
A.Carbon dioxide
B.Fiber
C.Undigested cellulose
D.Vitamin C
- 4.
Which part of the urinary system connects the kidney to the bladder?
A.Urethra
B.Ureter
C.Renal vein
D.Renal artery
- 5.
By what process is the majority of water reabsorbed in the kidney?
A.Active transport
B.Diffusion
C.Osmosis
D.Ultrafiltration
- 6.
What would be the effect on urine production if a person's pituitary gland was unable to secrete ADH?
A.Small volume of concentrated urine
B.Large volume of dilute urine
C.Small volume of dilute urine
D.No urine would be produced
- 7.
What role does the liver play in the excretory system?
A.Filtering the blood for urea
B.Storing urine before it is excreted
C.Converting excess amino acids into urea
D.Reabsorbing glucose from the blood
- 8.
In the provided flowchart representing the physiological conditions in the kidney's collecting duct, how would the presence of an unabsorbable solute (such as excess glucose) in the filtrate affect 'Process Z' and the final volume of urine?
A.Process Z increases, leading to a decrease in the volume of urine produced
B.Process Z decreases, leading to an increase in the volume of urine produced
C.Process Z increases, leading to an increase in the volume of urine produced
D.Process Z decreases, leading to a decrease in the volume of urine produced
- 9.
Which part of the kidney contains the glomeruli and the convoluted tubules?
A.Cortex
B.Medulla
C.Pelvis
D.Ureter
- 10.
What is the consequence of the counter-current flow mechanism in the kidney's vasa recta (capillaries surrounding the nephron)?
A.It maintains the osmotic gradient in the medulla by removing reabsorbed water without washing away the salts.
B.It increases the speed at which blood flows through the kidney to maximize filtration.
C.It allows for the direct exchange of urea between the renal artery and the renal vein.
D.It prevents the kidney from becoming too cold compared to the rest of the body.
Download the worksheet for Excretion in Humans - Structure and function of kidneys to practice offline. It includes additional chapter-level practice questions.
Dialysis and transplants
SubtopicDialysis and transplants under Excretion in Humans for Grade 11 IGCSE.
Preview questions (no answers)
- 1.
What is the main role of the dialysis fluid's salt concentration?
A.To provide the patient with extra energy
B.To balance the patient's blood electrolytes
C.To make the urea more soluble
D.To prevent the blood from freezing
- 2.
Why does dialysis treatment not require tissue matching?
A.Because the blood is returned to the same person
B.Because the machine uses artificial blood
C.Because urea does not have antigens
D.Because the dialysis fluid is sterile
- 3.
Which substance is added to blood during dialysis to prevent it from clotting in the machine?
A.Insulin
B.Heparin (an anti-coagulant)
C.Adrenaline
D.Glucagon
- 4.
In the context of transplants, what is an 'autograft'?
A.A transplant between identical twins
B.A transplant from one part of a person's body to another
C.A transplant from a deceased donor
D.A machine-based transplant
- 5.
If a donor kidney is not a close match to the recipient, what will the recipient's immune system produce to attack it?
A.Insulin
B.Antibodies
C.Urea
D.Hemoglobin
- 6.
Which statement about the dialysis membrane is true?
A.It is a fully permeable membrane
B.It is a partially permeable membrane
C.It is an impermeable membrane
D.It is a membrane that only allows urea to pass through
- 7.
Why is the blood returned to a vein rather than an artery after dialysis?
A.Veins have higher blood pressure than arteries
B.Veins have thinner walls and are easier to access
C.Arteries carry blood away from the heart, and we want to return it towards the heart
D.Veins contain valves that prevent the dialysis fluid from flowing backward
- 8.
If the dialysis membrane were to rupture during a session, which would be the most immediate sign?
A.The dialysis fluid in the 'used' outlet would become tinged with red (blood).
B.The patient's urea levels would immediately drop to zero.
C.The machine would start producing loud vibrating noises due to air intake.
D.The dialysis fluid would stop flowing due to the change in pressure.
- 9.
Comparing the energy requirements, how does dialysis compare to the function of a normal kidney?
A.Dialysis relies entirely on passive diffusion and pressure, while a kidney uses significant ATP for active transport.
B.Both rely solely on the kinetic energy of molecules for the movement of solutes.
C.Dialysis requires more energy from the patient's own metabolism than a normal kidney.
D.A normal kidney is purely passive, whereas a dialysis machine requires electricity.
- 10.
Why does the dialysis fluid NOT contain any urea?
A.To ensure the maximum possible concentration gradient for urea removal from the blood.
B.Because urea is toxic and would corrode the plastic components of the machine.
C.Because urea is a large molecule that cannot be synthesized in a laboratory.
D.To prevent urea from moving into the blood by active transport.
Download the worksheet for Excretion in Humans - Dialysis and transplants to practice offline. It includes additional chapter-level practice questions.