AQA A-LEVEL BIOLOGY Questions With Accurate Answers
Competitive Inhibitors - Accurate answers Bind to active site of the enzyme, occupies the active
site.
Non-Competitive Inhibitors - Accurate answers Bind to allosteric site of the enzyme, causes the
shape of active site to change.
Resolution - Accurate answers The minimum distance between two objects for them to appear as
separate items.
Magnification - Accurate answers Size of Image / Size of object
Diffusion - Accurate answers The net movement of molecules or ions from a higher concentration
region to a lower concentration region until evenly distributed.
Proportional to the surface area of exchange x concentration gradient / diffusion pathway
Osmosis - Accurate answers The passage of water from a higher water potential region to a lower
water potential region through a selectively permeable membrane.
Active Transport - Accurate answers The movement of molecules or ions from a lower
concentration region to a higher concentration region using ATP and carrier proteins.
Pathogen - Accurate answers Any organism that causes disease.
Antigen - Accurate answers Any part of an organism or molecule (usually a protein) that is
recognised as foreign by the immune system, and triggers an immune response.
Passive Immunity - Accurate answers The introduction of antibodies to an individual from an
outside source, direct contact with pathogen or antigen is not required.
Immunity is acquired immediately, but not long lasting.
Retroviruses - Accurate answers Virus that are able to produce DNA from RNA.
Active Immunity - Accurate answers Stimulating production of antibodies by the individual's own
immune system, through direct contact with the pathogen or antigen.
Takes time to develop, but long lasting.
Countercurrent Principle - Accurate answers Blood flows in opposite direction to water, water with
higher concentration of oxygen is always next to blood with lower concentration of oxygen, so a
concentration gradient is maintained along the whole length of the gill lamella, ensures maximum
amount of oxygen to be diffused into the blood.
, Risk Factors of Lung Disease - Accurate answers Smoking
Air Pollution
Genetic make-up
Infection
Occupation
Positive Cooperativity - Accurate answers The binding of the first molecule of oxygen to the
haemoglobin changes the conformation of the haemoglobin, easier for the next oxygen molecules to
bind to haemoglobin.
Note: it is difficult for the fourth oxygen molecule to bind to the haemoglobin due to low probability of
finding an empty site to bind to.
Risk Factors of Cardiovascular Disease - Accurate answers Smoking
1. Carbon Monoxide
2. Nicotine
High Blood Pressure
Blood Cholesterol
1. High Density Lipoprotein - removes cholesterol from from tissues and transport to liver for excretion
2. Low Density Lipoprotein - transport cholesterol from liver to tissues
Diets
1. High levels of salt
2. High levels of saturated fat
Translocation - Accurate answers The process by which organic molecules and some mineral ions
are transported from one part of a plant to another.
Gene - Accurate answers A base sequence of DNA that codes for the amino acid sequence of a
polypeptide or a functional RNA.
Triplet - Accurate answers A sequence of DNA bases that codes for a specific amino acid.
Locus - Accurate answers The location of a particular gene in the DNA sequence.
Degenerate - Accurate answers Most amino acids are coded by more than one triplet.
Non-Overlapping - Accurate answers Each base in the sequence is only read once.
Exons - Accurate answers Coding sequences.
Introns - Accurate answers Non-coding sequences.
Allele - Accurate answers One of the alternative forms of a gene.
Competitive Inhibitors - Accurate answers Bind to active site of the enzyme, occupies the active
site.
Non-Competitive Inhibitors - Accurate answers Bind to allosteric site of the enzyme, causes the
shape of active site to change.
Resolution - Accurate answers The minimum distance between two objects for them to appear as
separate items.
Magnification - Accurate answers Size of Image / Size of object
Diffusion - Accurate answers The net movement of molecules or ions from a higher concentration
region to a lower concentration region until evenly distributed.
Proportional to the surface area of exchange x concentration gradient / diffusion pathway
Osmosis - Accurate answers The passage of water from a higher water potential region to a lower
water potential region through a selectively permeable membrane.
Active Transport - Accurate answers The movement of molecules or ions from a lower
concentration region to a higher concentration region using ATP and carrier proteins.
Pathogen - Accurate answers Any organism that causes disease.
Antigen - Accurate answers Any part of an organism or molecule (usually a protein) that is
recognised as foreign by the immune system, and triggers an immune response.
Passive Immunity - Accurate answers The introduction of antibodies to an individual from an
outside source, direct contact with pathogen or antigen is not required.
Immunity is acquired immediately, but not long lasting.
Retroviruses - Accurate answers Virus that are able to produce DNA from RNA.
Active Immunity - Accurate answers Stimulating production of antibodies by the individual's own
immune system, through direct contact with the pathogen or antigen.
Takes time to develop, but long lasting.
Countercurrent Principle - Accurate answers Blood flows in opposite direction to water, water with
higher concentration of oxygen is always next to blood with lower concentration of oxygen, so a
concentration gradient is maintained along the whole length of the gill lamella, ensures maximum
amount of oxygen to be diffused into the blood.
, Risk Factors of Lung Disease - Accurate answers Smoking
Air Pollution
Genetic make-up
Infection
Occupation
Positive Cooperativity - Accurate answers The binding of the first molecule of oxygen to the
haemoglobin changes the conformation of the haemoglobin, easier for the next oxygen molecules to
bind to haemoglobin.
Note: it is difficult for the fourth oxygen molecule to bind to the haemoglobin due to low probability of
finding an empty site to bind to.
Risk Factors of Cardiovascular Disease - Accurate answers Smoking
1. Carbon Monoxide
2. Nicotine
High Blood Pressure
Blood Cholesterol
1. High Density Lipoprotein - removes cholesterol from from tissues and transport to liver for excretion
2. Low Density Lipoprotein - transport cholesterol from liver to tissues
Diets
1. High levels of salt
2. High levels of saturated fat
Translocation - Accurate answers The process by which organic molecules and some mineral ions
are transported from one part of a plant to another.
Gene - Accurate answers A base sequence of DNA that codes for the amino acid sequence of a
polypeptide or a functional RNA.
Triplet - Accurate answers A sequence of DNA bases that codes for a specific amino acid.
Locus - Accurate answers The location of a particular gene in the DNA sequence.
Degenerate - Accurate answers Most amino acids are coded by more than one triplet.
Non-Overlapping - Accurate answers Each base in the sequence is only read once.
Exons - Accurate answers Coding sequences.
Introns - Accurate answers Non-coding sequences.
Allele - Accurate answers One of the alternative forms of a gene.
