AQA GCSE Biology Paper 1 - Revision
Questions And Answers
How is the real size of a magnified image calculated? - ✔✔✔Real size = Image size ÷ Total
magnification.
What is a eukaryotic cell? - ✔✔✔A cell with DNA inside a membrane bound nucleus. Prokaryotic cells
do not have a nucleus.
Name two differences between a plant cell and a bacterial cell? - ✔✔✔Plant cells have a nucleus /
plant cells have mitochondria / plant cells have chloroplasts / plant cells have a cellulose cell wall
whereas bacteria do not contain any of these structures. Bacteria have chromosomal DNA not in a
nucleus and have DNA plasmids whereas plant cells do not contain these structures.
How can the rate of diffusion be increased? - ✔✔✔Higher temperature, Steeper concentration
gradient, Shorter diffusion distance
Why are stem cells used in medicine? - ✔✔✔Treatment with stem cells may be able to help conditions
such as diabetes and paralysis.
What is the lock and key model of enzyme action? - ✔✔✔The active site of an enzyme is a specific
shape, which is complimentary to its substrate - they fit together like a lock and key to form an enzyme-
substrate complex.
What happens when an enzyme is denatured? - ✔✔✔The active site changes shape and can no longer
bind with the substrate. The enzyme will no longer function
What is the test for a reducing sugar (such as glucose)? - ✔✔✔Heated with Benedict's reagent. A
change in colour from blue to green, orange or brick-red are all positive results.
Questions And Answers
How is the real size of a magnified image calculated? - ✔✔✔Real size = Image size ÷ Total
magnification.
What is a eukaryotic cell? - ✔✔✔A cell with DNA inside a membrane bound nucleus. Prokaryotic cells
do not have a nucleus.
Name two differences between a plant cell and a bacterial cell? - ✔✔✔Plant cells have a nucleus /
plant cells have mitochondria / plant cells have chloroplasts / plant cells have a cellulose cell wall
whereas bacteria do not contain any of these structures. Bacteria have chromosomal DNA not in a
nucleus and have DNA plasmids whereas plant cells do not contain these structures.
How can the rate of diffusion be increased? - ✔✔✔Higher temperature, Steeper concentration
gradient, Shorter diffusion distance
Why are stem cells used in medicine? - ✔✔✔Treatment with stem cells may be able to help conditions
such as diabetes and paralysis.
What is the lock and key model of enzyme action? - ✔✔✔The active site of an enzyme is a specific
shape, which is complimentary to its substrate - they fit together like a lock and key to form an enzyme-
substrate complex.
What happens when an enzyme is denatured? - ✔✔✔The active site changes shape and can no longer
bind with the substrate. The enzyme will no longer function
What is the test for a reducing sugar (such as glucose)? - ✔✔✔Heated with Benedict's reagent. A
change in colour from blue to green, orange or brick-red are all positive results.
