Describe how ultrafiltration occurs in a glomerulus - AQA - A-Level Biology - Question 1 - 2019 - Paper 1
Question 1
Describe how ultrafiltration occurs in a glomerulus.
High blood/hydrostatic pressure;
Two named small substances pass out eg water, glucose, ions, urea;
(Through sm... show full transcript
Worked Solution & Example Answer:Describe how ultrafiltration occurs in a glomerulus - AQA - A-Level Biology - Question 1 - 2019 - Paper 1
Step 1
High blood/hydrostatic pressure
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Answer
Ultrafiltration begins due to high blood pressure in the glomerulus, which forces fluid and small molecules through the capillary walls.
Step 2
Two named small substances pass out eg water, glucose, ions, urea
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Answer
During ultrafiltration, small substances such as water, glucose, ions, and urea pass out of the blood into the Bowman’s capsule.
Step 3
Through small gaps/pores/pfenestrations in (capillary) endothelium
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Answer
The filtration occurs through the gaps or pores in the capillary endothelium, allowing these small molecules to escape while retaining larger molecules like proteins.
Step 4
And through (capillary) basement membrane
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Answer
The final layer of filtration is the capillary basement membrane, which further prevents the passage of large proteins and retains the essential blood components.
