Kidney Functions and Malfunctions | OCR A-Level Biology B (Advancing Biology) (H422)
Kidney Functions and Malfunctions
- 87 questions
- 6 subtopics
- Biology content, examined on all three papers
- Component 01, Component 02 and Component 03
Kidney Functions and Malfunctions is examined in all three written papers — the specification states that Components 01, 02 and 03 can each assess content from any of the five modules, so nothing is confined to one paper.
It covers excretion and the gross structure of the kidney, the nephron: ultrafiltration and selective reabsorption, investigating the composition of urine, plasma and filtrate, osmoregulation and the action of ADH, the kidney as an endocrine gland and kidney failure and dialysis, transplantation and the future of transplant surgery.
Sample questions from Kidney Functions and Malfunctions
Answer each one closed book first, then open the answer.
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Excretion and the gross structure of the kidney
Why is ammonia converted into urea rather than being excreted as it is?
Show the answer
Ammonia is extremely soluble and highly toxic even at low concentrations, so the liver converts it into urea, which is far less toxic and can be carried safely in the blood until the kidney removes it. -
Excretion and the gross structure of the kidney
Trace the path taken by urine from the renal pelvis until it leaves the body.
Show the answer
It passes down the ureter to the bladder, where it is stored, and then leaves the body through the urethra. -
The nephron: ultrafiltration and selective reabsorption
How are podocytes adapted to their role?
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They have finger-like extensions that wrap around the capillary and leave narrow filtration slits between them, so filtrate passes freely into the capsule without the cells forming a complete barrier. -
The nephron: ultrafiltration and selective reabsorption
Why does water follow the solutes out of the proximal convoluted tubule?
Show the answer
Reabsorbing glucose, amino acids and ions raises the water potential of the filtrate and lowers that of the blood, so water leaves the tubule by osmosis down the water potential gradient. -
Investigating the composition of urine, plasma and filtrate
Which of glucose, protein and urea would you expect to find in a mock sample of glomerular filtrate?
Show the answer
Glucose and urea, but not protein. -
Investigating the composition of urine, plasma and filtrate
Why would you expect mock renal vein plasma to contain less urea than mock renal artery plasma?
Show the answer
Urea has been filtered out of the blood at the glomerulus and excreted in the urine, so the blood leaving the kidney carries less of it than the blood entering. -
Osmoregulation and the action of ADH
On which parts of the nephron does ADH act?
Show the answer
Mainly on the collecting ducts, and also on the distal convoluted tubules. -
Osmoregulation and the action of ADH
What is the full negative feedback response to drinking a large volume of water?
Show the answer
The water potential of the blood rises, so the osmoreceptors in the hypothalamus are less stimulated and less ADH is released from the posterior pituitary; the collecting ducts lose aquaporins and become less permeable, and a large volume of dilute urine is produced, which lowers the water potential of the blood again.
The 6 subtopics
One subtopic is one session. Work down the list.
| Subtopic | What it covers | Questions |
|---|---|---|
| Excretion and the gross structure of the kidney | Recall questions on excretion, deamination in the liver and its products, why ammonia becomes urea, the cortex, medulla, renal pyramids and pelvis, the renal artery and vein, the path of urine, renal blood flow, and dissecting a kidney safely. | 13 |
| The nephron: ultrafiltration and selective reabsorption | Recall questions on the parts of the nephron, ultrafiltration through endothelium, basement membrane and podocytes, what glomerular filtrate contains, reabsorption of glucose by co-transport in the proximal convoluted tubule, the loop of Henle and collecting duct, and the distal convoluted tubule. | 15 |
| Investigating the composition of urine, plasma and filtrate | Recall questions on why mock samples are used, testing for glucose, protein and urea, what filtrate should not contain, artery and vein comparisons, and colorimetric measurement. | 12 |
| Osmoregulation and the action of ADH | Recall questions on where the osmoreceptors sit, the route ADH takes, cyclic AMP and aquaporins in the collecting duct, and the feedback response to drinking heavily or sweating. | 14 |
| The kidney as an endocrine gland and kidney failure | Recall questions on the hormone that drives erythrocyte production, renin and angiotensin II raising blood pressure, the causes of kidney damage, albumin in urine, and estimating filtration rate. | 15 |
| Dialysis, transplantation and the future of transplant surgery | Recall questions on the composition of dialysis fluid and countercurrent flow, haemodialysis and peritoneal dialysis compared, kidney transplants, tissue matching and immunosuppressants, living donors, and therapeutic cloning, its ethics, reproductive cloning and induced pluripotent stem cells. | 18 |
How the guide is worked
Answering a question from memory stores it far better than reading the answer again. The guide runs that as a fixed procedure on one subtopic at a time, about twenty minutes a session.
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Step 1 · Closed book
Cover the answers. Work through one subtopic and write down what you can. Leave blanks where you have nothing.
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Step 2 · Open book
Go back to the top. Read each printed answer and write it out in full, including the ones you had right.
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Step 3 · Closed book again
Same questions, same order, from memory. The gap between pass one and pass three is the session result.
Read the full method, the return schedule and the research behind it.
Nearby topics
OCR A-Level Biology B (Advancing Biology) Active Recall Guide
Every topic, not just this one. 2,895 questions with their answers.