AQA A Level Biology Year 1 Questions
With Correct Answers
What is diversity index? - CORRECT ANSWER- Where N is total organisms of all
species and n is total number of organisms of one species. The higher the area, the
more diverse. It is 1 if they are all one species.
Impact of agriculture on biodiversity: - CORRECT ANSWER- Woodland clearance
reduces species, lowers biodiversity, destroys habitat, and species migrate lowering it
further.
Hedgerow removal same effect.
Pesticides kill insects, lowering bd and also affects what eats them, lowering it further.
Herbicides kill weeds, lower bd and removing a food source, further lowering it.
Monoculture only grows one crop, lowering bd and is able to support less species.
Why is biodiversity important? - CORRECT ANSWER- Produce food and fibres for
clothing, to make medicines and fuels. Provides new sources of food and medicine, and
benefit agriculture as large insect populations will pollinate crops.
How to work out if there is a correlation between two variables. - CORRECT
ANSWER- Use the Spearman's rank correlation coefficient. Between -1 (perfect
negative) and +1 (perfect positive correlation.
What is a null hypothesis? - CORRECT ANSWER- Something that always suggests
there is no correlation. It can then be rejected or kept according to Spearman's rank
correlation coefficient.
How do biological molecules provide evidence for evolution? - CORRECT ANSWER-
They all have similar molecules and use the same amino acids and DNA.
What are monomers of carbohydrates called? - CORRECT ANSWER-
Monosaccharides.
Beta Glucose - CORRECT ANSWER-
Alpha glucose - CORRECT ANSWER-
Glucose formula - CORRECT ANSWER- C₆H₁₂O₆
Name of the bond between monosaccharides? - CORRECT ANSWER- Glycosidic
bond.
What is sucrose made from? - CORRECT ANSWER- Glucose and fructose.
What is lactose made from? - CORRECT ANSWER- Glucose and galactose.
,What is maltose made from? - CORRECT ANSWER- Two alpha glucose.
Testing for reducing sugars? - CORRECT ANSWER- Add Benedict's reagent (blue)
and heat in a water bath at a boil. If present: Green → yellow → orange → brick red
Test for non-reducing sugars? - CORRECT ANSWER- Add dilute hydrochloric acid
and heat, neutralise with Sodium Hydrogencarbonate and add Benedicts reagent.
What is the scientific name for carbohydrates? - CORRECT ANSWER-
Polysaccharides.
What is starch made of? - CORRECT ANSWER- Starch is a mixture of two
polysaccharides of alpha glucose: Amylose and amylopectin.
What is amylose? - CORRECT ANSWER- A long, unbranched alpha glucose chain.
The angles in it make it have a coiled shape which makes it compact and effective for
storage.
What is amylopectin? - CORRECT ANSWER- A long, braqnched alpha glucose
chain. The side branches mean that enzymes can get to and hydrolise glycosidic bonds
faster so glucose can be released quickly.
What is glycogen? - CORRECT ANSWER- A polysaccharide of alpha glucose with a
similar structure to starch except it is more branched, allowing even faster energy
release. It is also very compact.
What is celluose? - CORRECT ANSWER- it is made of long. straight chains of beta
glucose. The chains are linked my hydrogen bonds to form microfibrils, a strong fibre.
The strong fibres allow it to provide structural support in cells as cell walls.
How to test for starch. - CORRECT ANSWER- Add iodine which is dissolved in
potassium iodie ti the sample. Positive result: Turns blue-black. Negative result: stays
browny-orange.
Which of proteins, polysaccharides and lipids are not a polymer. - CORRECT
ANSWER- Lipids.
What are triglycerides made of? - CORRECT ANSWER- Glycerol and fatty acids.
What causes lipids to be insoluble in water? - CORRECT ANSWER- The
hydrophobic fatty acid tails.
What is the structure of a fatty acid? - CORRECT ANSWER-
What do double bonds cause in fatty acids? - CORRECT ANSWER- A kink in the
chain.
, Triglyceride formation? - CORRECT ANSWER-
What are phospholipids? - CORRECT ANSWER- Similar to triglycerides, but one of
the fatty acid tails is replaced by a phosphate group head.
Which part of a phospholipid is hydrophillic and which part is hydrophobic? -
CORRECT ANSWER- The phosphate group is hydrophillic and the fatty acid tail is
hydrophobic.
What are triglycerides mainly used for? - CORRECT ANSWER- To store energy,
they are effective at this as the hydrocarbon tails contain a lot of energy. They are also
insoluble so do not affect the water potential of cells, preventing swelling.
How much energy do lipids contain compared to carbohydrates? - CORRECT
ANSWER- Twice as much energy per gram.
Why do triglycerides bundle together in water? - CORRECT ANSWER- The fatty
acid tails are hydrophobic so face inwards, so are shielded by the glycerol heads.
What role do phospholipids perform? - CORRECT ANSWER- They make up the
bilayer in cell membranes.
Test for lipids? - CORRECT ANSWER- The emulsion test: Shake substance with
ethanol and pour into water. A white emulsion forms if it is present.
What are proteins made of? - CORRECT ANSWER- Amino acids.
What is the bond between amino acids called? - CORRECT ANSWER- Peptide
bond.
Amino acid structure. - CORRECT ANSWER- Amino group, variable group, carboxyl
group.
What is a primary structure? - CORRECT ANSWER- Polypeptide chain.
What is a secondary structure? - CORRECT ANSWER- Chain twists into alpha helix
or folds in beta pleated sheet.
What is a tertiary structure? - CORRECT ANSWER- Chain coils further, forming
hydrogen bonds, ionic bonds and disulphide bridges.
When do disulphide bridges form? - CORRECT ANSWER- When the sulphur atoms
on the amino acid cysteine form sulphur bonds.
What is a Quaternary structure> - CORRECT ANSWER- Like tertiary, but made of
several chains.
With Correct Answers
What is diversity index? - CORRECT ANSWER- Where N is total organisms of all
species and n is total number of organisms of one species. The higher the area, the
more diverse. It is 1 if they are all one species.
Impact of agriculture on biodiversity: - CORRECT ANSWER- Woodland clearance
reduces species, lowers biodiversity, destroys habitat, and species migrate lowering it
further.
Hedgerow removal same effect.
Pesticides kill insects, lowering bd and also affects what eats them, lowering it further.
Herbicides kill weeds, lower bd and removing a food source, further lowering it.
Monoculture only grows one crop, lowering bd and is able to support less species.
Why is biodiversity important? - CORRECT ANSWER- Produce food and fibres for
clothing, to make medicines and fuels. Provides new sources of food and medicine, and
benefit agriculture as large insect populations will pollinate crops.
How to work out if there is a correlation between two variables. - CORRECT
ANSWER- Use the Spearman's rank correlation coefficient. Between -1 (perfect
negative) and +1 (perfect positive correlation.
What is a null hypothesis? - CORRECT ANSWER- Something that always suggests
there is no correlation. It can then be rejected or kept according to Spearman's rank
correlation coefficient.
How do biological molecules provide evidence for evolution? - CORRECT ANSWER-
They all have similar molecules and use the same amino acids and DNA.
What are monomers of carbohydrates called? - CORRECT ANSWER-
Monosaccharides.
Beta Glucose - CORRECT ANSWER-
Alpha glucose - CORRECT ANSWER-
Glucose formula - CORRECT ANSWER- C₆H₁₂O₆
Name of the bond between monosaccharides? - CORRECT ANSWER- Glycosidic
bond.
What is sucrose made from? - CORRECT ANSWER- Glucose and fructose.
What is lactose made from? - CORRECT ANSWER- Glucose and galactose.
,What is maltose made from? - CORRECT ANSWER- Two alpha glucose.
Testing for reducing sugars? - CORRECT ANSWER- Add Benedict's reagent (blue)
and heat in a water bath at a boil. If present: Green → yellow → orange → brick red
Test for non-reducing sugars? - CORRECT ANSWER- Add dilute hydrochloric acid
and heat, neutralise with Sodium Hydrogencarbonate and add Benedicts reagent.
What is the scientific name for carbohydrates? - CORRECT ANSWER-
Polysaccharides.
What is starch made of? - CORRECT ANSWER- Starch is a mixture of two
polysaccharides of alpha glucose: Amylose and amylopectin.
What is amylose? - CORRECT ANSWER- A long, unbranched alpha glucose chain.
The angles in it make it have a coiled shape which makes it compact and effective for
storage.
What is amylopectin? - CORRECT ANSWER- A long, braqnched alpha glucose
chain. The side branches mean that enzymes can get to and hydrolise glycosidic bonds
faster so glucose can be released quickly.
What is glycogen? - CORRECT ANSWER- A polysaccharide of alpha glucose with a
similar structure to starch except it is more branched, allowing even faster energy
release. It is also very compact.
What is celluose? - CORRECT ANSWER- it is made of long. straight chains of beta
glucose. The chains are linked my hydrogen bonds to form microfibrils, a strong fibre.
The strong fibres allow it to provide structural support in cells as cell walls.
How to test for starch. - CORRECT ANSWER- Add iodine which is dissolved in
potassium iodie ti the sample. Positive result: Turns blue-black. Negative result: stays
browny-orange.
Which of proteins, polysaccharides and lipids are not a polymer. - CORRECT
ANSWER- Lipids.
What are triglycerides made of? - CORRECT ANSWER- Glycerol and fatty acids.
What causes lipids to be insoluble in water? - CORRECT ANSWER- The
hydrophobic fatty acid tails.
What is the structure of a fatty acid? - CORRECT ANSWER-
What do double bonds cause in fatty acids? - CORRECT ANSWER- A kink in the
chain.
, Triglyceride formation? - CORRECT ANSWER-
What are phospholipids? - CORRECT ANSWER- Similar to triglycerides, but one of
the fatty acid tails is replaced by a phosphate group head.
Which part of a phospholipid is hydrophillic and which part is hydrophobic? -
CORRECT ANSWER- The phosphate group is hydrophillic and the fatty acid tail is
hydrophobic.
What are triglycerides mainly used for? - CORRECT ANSWER- To store energy,
they are effective at this as the hydrocarbon tails contain a lot of energy. They are also
insoluble so do not affect the water potential of cells, preventing swelling.
How much energy do lipids contain compared to carbohydrates? - CORRECT
ANSWER- Twice as much energy per gram.
Why do triglycerides bundle together in water? - CORRECT ANSWER- The fatty
acid tails are hydrophobic so face inwards, so are shielded by the glycerol heads.
What role do phospholipids perform? - CORRECT ANSWER- They make up the
bilayer in cell membranes.
Test for lipids? - CORRECT ANSWER- The emulsion test: Shake substance with
ethanol and pour into water. A white emulsion forms if it is present.
What are proteins made of? - CORRECT ANSWER- Amino acids.
What is the bond between amino acids called? - CORRECT ANSWER- Peptide
bond.
Amino acid structure. - CORRECT ANSWER- Amino group, variable group, carboxyl
group.
What is a primary structure? - CORRECT ANSWER- Polypeptide chain.
What is a secondary structure? - CORRECT ANSWER- Chain twists into alpha helix
or folds in beta pleated sheet.
What is a tertiary structure? - CORRECT ANSWER- Chain coils further, forming
hydrogen bonds, ionic bonds and disulphide bridges.
When do disulphide bridges form? - CORRECT ANSWER- When the sulphur atoms
on the amino acid cysteine form sulphur bonds.
What is a Quaternary structure> - CORRECT ANSWER- Like tertiary, but made of
several chains.
