AQA GCSE Combined Science Biology Paper 1 (8464) – Full Revision Notes on Cells, Enzymes, Organisation, Infection & Bioenergetics

5/6/26, 6:44 Edexcel gcse combined sci
AM




AQA GCSE Combined Science Biology Paper 1 (8464) –
Full Revision Notes on Cells, Enzymes, Organisation,
Infection & Bioenergetics.

What is the function of the nucleus?
Contains DNA to control the cell


What is the function of the cell membrane?
Controls entry and exit of substances


What is the function of the cell wall?
Provides structure and support


What is the function of mitochondria?
Carry out respiration to release energy


What is the function of ribosomes?
Protein synthesis


What is the function of chloroplasts?
Carry out photosynthesis


What is the function of a vacuole?
Contains cell sap


Define a prokaryote
A cell that does not have a nucleus


Define a eukaryote
A cell that has DNA in a nucleus


Name two cell structures that are in a eukaryote but not in a prokaryote
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,5/6/26, 6:44 Edexcel gcse combined sci
AM
Nucleus, mitochondria, chloroplasts




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, 5/6/26, 6:44 Edexcel gcse combined sci
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What is a plasmid?
A small loop of DNA in bacteria


What is a plant cell wall made from?
Cellulose


How is DNA stored in a bacterial cell?
As a single, free-floating loop; also on plasmids


What is differentiation?
The process by which cells become specialised


What is the equation for magnification?
Magnification = Image Size ÷ Actual Size


A photograph of a cell is 15mm long. It has a magnification of 1100x. What is the
actual size?
0.0136mm, or 13.6µm


A cell is 12µm wide. It is magnified by 450 times. How big is the image?
5400µm, or 5.4mm


If the image of a virus is 1.2mm, and its actual size is 0.2µm, how much has it been
magnified by?
6000 times


Convert 38500µm into mm

38.5mm


How many µm are in 1mm?
1000


Write 17400m in standard form
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