AQA A LEVEL BIOLOGY PAPER 1 EXAM QUESTIONS AND CORRECT VERIFIED ANSWERS LATEST UPDATE 2023/2024 BEST EXAM SOLUTION GRADED A+ FOR SUCCESS

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AQA A LEVEL BIOLOGY PAPER 1 EXAM QUESTIONS AND CORRECT
VERIFIED ANSWERS LATEST UPDATE 2023/2024 BEST EXAM
SOLUTION GRADED A+ FOR SUCCESS.

Water removed from the reactants joining two molecules together forming a chemical bond
- CORRECT ANSWERS Condensation



The addition of water to the reactants to break a chemical bond between 2 molecules -
CORRECT ANSWERS Hydrolysis



1. Add Benedict's reagent. 2. Heat the solution in a water bath for 5 minutes at 95 degrees
Celsius. 3. Change from blue to brick red as CuO formed - CORRECT ANSWERS Test for
Reducing Sugars (3)



Smaller units from which larger molecules are made - CORRECT ANSWERS Monomer



1. Add 2cm³ of food sample then add 2cm³ of dilute HCl and heat.

2. Add 2cm³ of NaHCO3 then do test for reducing sugars. - CORRECT ANSWERS Non-
Reducing Sugars (2)



Add drops of iodine to starch solution. Colour change to blue-black - CORRECT ANSWERS
Test for Starch (1)



1. Mix Test solution with ethanol.

2. Shake for 1 minute then add water.

3. Cloudy white emulsion - CORRECT ANSWERS Test for Lipids (3)



1. Obtain equal volumes of test solution and NaOH then add a few drops of biuret solution
(dilute copper (II) sulphate solution).

2. Colour change to mauve/purple - CORRECT ANSWERS Test for Proteins (2)



1. Very high resolution.

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AQA A LEVEL BIOLOGY PAPER 1 EXAM QUESTIONS AND CORRECT
VERIFIED ANSWERS LATEST UPDATE 2023/2024 BEST EXAM
SOLUTION GRADED A+ FOR SUCCESS.
2. Needs thin and dead specimen.

3. Artefacts can occur (remnant left on object during prep, such as air bubbles)

4. Uses magnets to focus on specimen

5. Uses electrons fired at sample.

6. Is not in colour - CORRECT ANSWERS Transmission Electron Microscope (5)



1. Inhibitor is similar in shape to substrate so it impermanently binds to the active site.

2. Prevents ESC from forming, slowing rate - CORRECT ANSWERS Competitive inhibition (2)



1. Molecule will bind to allosteric site.

2. Binding causes a change in active site.

3. Permanently preventing further ESC. - CORRECT ANSWERS Non-competitive inhibition (3)



1. DNA helicase breaks the hydrogen bonds between the base pairs

2. 2 single strands formed as the double helix "unzips".

3. Free DNA nucleotides in the nucleoplasm bond to the complementary bases on the
strand.

4. DNA polymerase forms phosphodiester bonds between adjacent DNA nucleotides via
condensation reaction with the hydrolysis of ATP, forming the phosphate backbone -
CORRECT ANSWERS DNA Replication: Semiconservative (4)



1. ATP stores or releases only a small amount of energy at a time, so no energy is wasted as
heat.

2. Small and soluble so easily transported

3. Easily broken down, so energy is released instantaneously

4. Can be quickly re-made

5. Can make other molecules more reactive via phosphorylation

6. ATP can't pass out of cell, so the cell always has an immediate supply of energy. -
CORRECT ANSWERS Describe 6 properties of ATP that make it a good energy source. (6)

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AQA A LEVEL BIOLOGY PAPER 1 EXAM QUESTIONS AND CORRECT
VERIFIED ANSWERS LATEST UPDATE 2023/2024 BEST EXAM
SOLUTION GRADED A+ FOR SUCCESS.

Prevents the cell from drying out. Allows bacteria to stick to each other - CORRECT
ANSWERS Slime capsule (2)



Used for attachment of a cell to a surface - CORRECT ANSWERS Fimbria



Involved in bacterial conjugation - CORRECT ANSWERS Pilli



Invagination of cell membrane. Site of cell respiration (prokaryotes) - CORRECT ANSWERS
Mesosome



The ability to distinguish two points apart - CORRECT ANSWERS Resolution



1. Lower resolution than TEM

2. 3D image

3. Does not require thin samples - CORRECT ANSWERS Scanning Electron Microscope



The mass of organelles at the bottom of the test tube after centrifugation. - CORRECT
ANSWERS Pellet



Cold. Low temperature slows enzyme activity, minimising self digestion by reducing
metabolic rate. Isotonic. Salt and sugar concentration kept the same, minimising organelle
size change due to osmosis. Buffered. Minimum changes in pH, so prevents enzymes in
organelles denaturing. - CORRECT ANSWERS Solution Required for cell fractionation (6
Marks)



1. Homogenisation. Breaking up cells by blending the sample to create a homogenate.

2. Filtering. Filtering the large, unwanted sil, producing the filtrate.

3. Ultracentrifugation. Spin in a centrifuge so components separate out by weight. Heavier
near the bottom of the tube.

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AQA A LEVEL BIOLOGY PAPER 1 EXAM QUESTIONS AND CORRECT
VERIFIED ANSWERS LATEST UPDATE 2023/2024 BEST EXAM
SOLUTION GRADED A+ FOR SUCCESS.
4. Supernatant is removed and spun again at higher speed. - CORRECT ANSWERS
Separation of Organelles From The Cells (4)



The solution not including the pellet at the bottom of the test tube after centrifugation. -
CORRECT ANSWERS Supernatant



1. Cell wall forms, dividing the two genetically identical daughter cells.

2. Same circular DNA. - CORRECT ANSWERS Binary Fission 3



Nuclei, Chloroplasts, Mitochondria, Lysosomes, Endoplasmic Reticulum, Ribosomes -
CORRECT ANSWERS Order of Organelles



(Pass me a taco chief) - CORRECT ANSWERS Mitosis acronym



Cell grows and carrys out its normal function - CORRECT ANSWERS Interphase



Cells grow to normal size. Organelles replicate and genes are expressed to make proteins
needed. - CORRECT ANSWERS Interphase G1



DNA and histones replicated. - CORRECT ANSWERS Interphase S



Spindle fibres are made - CORRECT ANSWERS Interphase G2



1. DNA winds up making chromosones from chromatin.

2. Centrioles appear at opposite poles of the cell. 3. Nucleolus disappears - CORRECT
ANSWERS Prophase (3)



1. Nuclear envelope disappears.

2. Chromosomes align along the equator of the cell.