AQA A LEVEL BIOLOGY 7402 3
PAPER 3 JUNE 2022 STUDY GUIDE
QUESTIONS AND VERIFIED
ANSWERS GRADE A+
◉ Ways to increase reliability of study. Answer: 1) use a wider/narrower
range of concentrations (depending on questions);
2) use at least five more concentrations;
3) use a method to ensure controlled variables are maintained;
4) run experiments one at a time / stagger the start times;
5) repeat measurements for each concentration and calculate the mean ;
◉ The apparatus use to measure colour intensity quantitatively. Answer:
Colorimeter
◉ How to determine the level of risk of experiment? (Low, medium,
high). Answer: The risk level is higher if there are:
1) Harmful chemicals (harmful/ irritant)
2) Heat
3) sharp objects
◉ Beaker. Answer:
◉ Boiling tube / Large test tube. Answer:
, ◉ test tube rack. Answer: Holds test tubes
◉ two types of dilution. Answer: 1) Proportional
2) Serial
◉ Proportional dilution. Answer: A dilution solution contains solute (or
stock solution) and a solvent (called diluent). These two components
proportionally combine to create a dilution. You can identify a dilution
solution by the amount of solute in the total volume, expressed as a
proportion.
Make a dilution table
◉ Drawing a large plan diagram of plants. Answer: 1) Use the 10x
objective lens
2) uses most of the available space, at least two layers of tissue, no
shading ;
3) draws part of plant organ and no individual cells ;
4) draws correct shape of plant organ ;
5) shows subdivision of the vascular tissue ;
6) label line and label to identify the tissue instructed in the question;
◉ The differences between normal plant and xerophytes (plants that live
in very dry environment). Answer: 1) sunken stomata
PAPER 3 JUNE 2022 STUDY GUIDE
QUESTIONS AND VERIFIED
ANSWERS GRADE A+
◉ Ways to increase reliability of study. Answer: 1) use a wider/narrower
range of concentrations (depending on questions);
2) use at least five more concentrations;
3) use a method to ensure controlled variables are maintained;
4) run experiments one at a time / stagger the start times;
5) repeat measurements for each concentration and calculate the mean ;
◉ The apparatus use to measure colour intensity quantitatively. Answer:
Colorimeter
◉ How to determine the level of risk of experiment? (Low, medium,
high). Answer: The risk level is higher if there are:
1) Harmful chemicals (harmful/ irritant)
2) Heat
3) sharp objects
◉ Beaker. Answer:
◉ Boiling tube / Large test tube. Answer:
, ◉ test tube rack. Answer: Holds test tubes
◉ two types of dilution. Answer: 1) Proportional
2) Serial
◉ Proportional dilution. Answer: A dilution solution contains solute (or
stock solution) and a solvent (called diluent). These two components
proportionally combine to create a dilution. You can identify a dilution
solution by the amount of solute in the total volume, expressed as a
proportion.
Make a dilution table
◉ Drawing a large plan diagram of plants. Answer: 1) Use the 10x
objective lens
2) uses most of the available space, at least two layers of tissue, no
shading ;
3) draws part of plant organ and no individual cells ;
4) draws correct shape of plant organ ;
5) shows subdivision of the vascular tissue ;
6) label line and label to identify the tissue instructed in the question;
◉ The differences between normal plant and xerophytes (plants that live
in very dry environment). Answer: 1) sunken stomata
