AQA A LEVEL BIOLOGY REVISION EXAM SET OF
QUESTIONS AND CORRECT ANSWERS ALREADY
GRADE A+ GUARANTEED SUCCESS
Describe a chemical test you could carry out to show that a piece of coconut contains lipids. [3]
(Crush in) ethanol / alcohol; Add (to) water (Order of adding is critical for this point); Emulsion /
white colour
Explain how you would calculate the volume of a sphere
Measure the radius ; Repeat and calculate a mean radius Use formula =4/3 πr^3
Describe the structure of starch and explain how its structure is related to its function. [3]
Formed from α glucose; Joined by condensation/ by the removal of a water molecule/ glycosidic
bonds; Between (carbons) 1 and 4 (and 1 and 6); Coiled chain; compact; (Allows) storage of
large amount in a small space; Insoluble so has no effect on osmosis/water potential; Branches;
(Allows) rapid breakdown/release of glucose / hydrolysis;
Explain why we collect a large number of results
allows anomalies to be identified / increases reliability (of means / averages / results); allows use
of statistical test; effect of variation in data to be minimised;
Genetic diversity can be compared within, or between species by investigation of? (3 marks)
DNA Base sequences, amino acids sequences, immunological comparisons
Explain how inhibitors affect the rate of enzyme-controlled reactions. [6]
Statement about two types, competitive and non-competitive; Competitive: Similar shape to
substrate;Inhibitor can enter/bind with active site (of enzyme);Non-competitive: Affect/bind to
enzyme other than at active site; Distorts shape of active site; Inhibitors: Prevent entry of/binding
of substrate to active site; Therefore fewer/no enzyme-substrate complexes formed;
When collecting variation data how do we ensure it is reliable? (1 mark)
Large and random samples taken/ mean SD calculated
What is species richness(1 mark)
the number of different species in a community
What do you need to calculate an index of diversity (1 mark)
Number of individuals of each species and total number of individuals of all species
, Explain what is meant by a polymer. [1]
Molecule) made up of many identical/similar molecules/monomers/ subunits;
Name the reaction which occurs when starch is broken down into maltose. [1]
Hydrolysis
What is the formula for lactose? [2]
C12 ; H22Ō1
Describe how β-glucose molecule differs from a molecule of α-glucose. [1]
H at top right end (instead of OH) / OH at bottom (carbon 1)
Show two ways in which the structure of cellulose is different from the structure of starch. [2]
Starch 1,4 and 1,6 bonds / branching Cellulose 1,4 bonds / no 1,6 bonds / straight; starch All
glucoses /monomers same way up cellulose Alternate glucoses upside down; starch Helix /
coiled/compact cellulose Straight; Starch monomer Alpha glucose Cellulose monomer Beta
glucose
The structure of a phospholipid molecule is different from that of a triglyceride. Describe how.
[2]
triglyceride has three fatty acids and phospholipid has two; no phosphate group present in
triglyceride but present in phospholipid.
What is an unsaturated fatty acid? [1]
Some / two carbons with only one hydrogen / (double bonds) between carbon atoms / not
saturated with hydrogen;
Describe the structure of cellulose and explain how its structure is related to its function. [3]
Alternate β-glucose rotated 180o, long straight chains, Many hydrogen bonds join
(polysaccharide) chains/molecules to each other / makes microfibrils / gives tensile strength;
Which elements are found in proteins? [1]
Carbon, hydrogen, oxygen, nitrogen (sometimes sulphur)
Describe how you would use a biochemical test to show that a solution contained protein. [2]
Biuret / alkali + copper sulphate; Lilac/purple/mauve/violet;
Which bonds are found in a)Primary structure [1]b)Secondary structure [1] c)Tertiary structure
[2]
a)Peptide b) Hydrogen (and peptide) c)Ionic, disulphide bridges, hydrophobic interactions
(hydrogen and peptide)
QUESTIONS AND CORRECT ANSWERS ALREADY
GRADE A+ GUARANTEED SUCCESS
Describe a chemical test you could carry out to show that a piece of coconut contains lipids. [3]
(Crush in) ethanol / alcohol; Add (to) water (Order of adding is critical for this point); Emulsion /
white colour
Explain how you would calculate the volume of a sphere
Measure the radius ; Repeat and calculate a mean radius Use formula =4/3 πr^3
Describe the structure of starch and explain how its structure is related to its function. [3]
Formed from α glucose; Joined by condensation/ by the removal of a water molecule/ glycosidic
bonds; Between (carbons) 1 and 4 (and 1 and 6); Coiled chain; compact; (Allows) storage of
large amount in a small space; Insoluble so has no effect on osmosis/water potential; Branches;
(Allows) rapid breakdown/release of glucose / hydrolysis;
Explain why we collect a large number of results
allows anomalies to be identified / increases reliability (of means / averages / results); allows use
of statistical test; effect of variation in data to be minimised;
Genetic diversity can be compared within, or between species by investigation of? (3 marks)
DNA Base sequences, amino acids sequences, immunological comparisons
Explain how inhibitors affect the rate of enzyme-controlled reactions. [6]
Statement about two types, competitive and non-competitive; Competitive: Similar shape to
substrate;Inhibitor can enter/bind with active site (of enzyme);Non-competitive: Affect/bind to
enzyme other than at active site; Distorts shape of active site; Inhibitors: Prevent entry of/binding
of substrate to active site; Therefore fewer/no enzyme-substrate complexes formed;
When collecting variation data how do we ensure it is reliable? (1 mark)
Large and random samples taken/ mean SD calculated
What is species richness(1 mark)
the number of different species in a community
What do you need to calculate an index of diversity (1 mark)
Number of individuals of each species and total number of individuals of all species
, Explain what is meant by a polymer. [1]
Molecule) made up of many identical/similar molecules/monomers/ subunits;
Name the reaction which occurs when starch is broken down into maltose. [1]
Hydrolysis
What is the formula for lactose? [2]
C12 ; H22Ō1
Describe how β-glucose molecule differs from a molecule of α-glucose. [1]
H at top right end (instead of OH) / OH at bottom (carbon 1)
Show two ways in which the structure of cellulose is different from the structure of starch. [2]
Starch 1,4 and 1,6 bonds / branching Cellulose 1,4 bonds / no 1,6 bonds / straight; starch All
glucoses /monomers same way up cellulose Alternate glucoses upside down; starch Helix /
coiled/compact cellulose Straight; Starch monomer Alpha glucose Cellulose monomer Beta
glucose
The structure of a phospholipid molecule is different from that of a triglyceride. Describe how.
[2]
triglyceride has three fatty acids and phospholipid has two; no phosphate group present in
triglyceride but present in phospholipid.
What is an unsaturated fatty acid? [1]
Some / two carbons with only one hydrogen / (double bonds) between carbon atoms / not
saturated with hydrogen;
Describe the structure of cellulose and explain how its structure is related to its function. [3]
Alternate β-glucose rotated 180o, long straight chains, Many hydrogen bonds join
(polysaccharide) chains/molecules to each other / makes microfibrils / gives tensile strength;
Which elements are found in proteins? [1]
Carbon, hydrogen, oxygen, nitrogen (sometimes sulphur)
Describe how you would use a biochemical test to show that a solution contained protein. [2]
Biuret / alkali + copper sulphate; Lilac/purple/mauve/violet;
Which bonds are found in a)Primary structure [1]b)Secondary structure [1] c)Tertiary structure
[2]
a)Peptide b) Hydrogen (and peptide) c)Ionic, disulphide bridges, hydrophobic interactions
(hydrogen and peptide)
