AQA AS Biology Paper 1 Exam Questions
First heat the sample with an acid in a water bath and neutralise, then heat with
Benedict solution in a water bath for five minutes. A positive test should produce a red
precipitate. - questions and answersDescribe a biochemical test to show that raffinose
solution contains a non-reducing sugar.
Phospholipids are arranged in a phospholipid bilayer. The hydrophobic fatty acid tails
point away from the water and the hydrophilic heads attract the water. - questions and
answersExplain the arrangement of phospholipids in a cell-surface membrane.
An ester bond is formed between a glycerol and a fatty acid, producing a water
molecule in a condensation reaction. - questions and answersDescribe how an ester
bond is formed in a phospholipid molecule.
Water has a high specific heat capacity. This buffers changes in temperature, so lots of
energy is required to change the temperature. - questions and answersState and
explain the property of water that helps to prevent temperature increase in a cell.
The phagocyte is attracted to the pathogen by chemoattractants. The phagocyte binds
to the pathogen. The pathogen is engulfed and lysosomes migrate to the phagosome.
The lysosomes then release lytic enzymes which break down the pathogen. The
breakdown products are then absorbed by the phagocyte. - questions and
answersDescribe how a phagocyte destroys a pathogen present in the blood.
Cancer cells and virus infected cells. - questions and answersGive two types of cell,
other than pathogens, that can stimulate an immune response.
It joins two polypeptide chains - questions and answersWhat is the role of a disulphide
bridge in forming the quaternary structure of an antibody.
DNA in the nucleus codes for the amino acids which make up proteins. Ribosomes on
the RER then synthesise these proteins. Mitochondria produce ATP for use in protein
synthesis. The Golgi apparatus then packages and modifies proteins which are
transported to the cell surface membrane in vesicles where they fuse. - questions and
answersOutline the role of organelles in the production, transport and release of
proteins from Eukaryotic cells.
Do not include details of transcription or translation in your answer.
, There is a higher resolution / view internal structures - questions and answersGive one
advantage of viewing a biological specimen using a transmission electron microscope
compared with using a scanning electron microscope.
The diaphragm muscle contracts and external intercostal muscles contract. This causes
an increase in volume and decrease in pressure. This causes air to move down the
pressure gradient and into the lungs. - questions and answersDescribe and explain the
mechanism that causes lungs to fill with air.
The tissue doesn't contain starch and it makes the nucleus, which contains DNA,
visible. - questions and answersTwo solutions often used to stain tissues are
haematoxylin solution and iodine solution.
• Haematoxylin solution stains DNA a blue colour. • Iodine solution stains starch a
blue-black colour.
The scientist used haematoxylin solution and not iodine solution to stain the lung tissue.
Suggest why.
Free RNA nucleotides form complementary base pairs. RNA polymerase then forms
phosphodiester bonds. - questions and answersDescribe how mRNA is produced from
an exposed template strand of DNA. Do not include DNA helices or splicing in your
answer.
A triplet base sequence which codes for a sequence of amino acids. - questions and
answersDefine the term exon.
Circular DNA and plasmids are replicated, tenth cytoplasm divides producing two
daughter cells. - questions and answersDescribe binary fission in bacteria.
Increase the concentration of glucose and oxygen to increase the rate of respiration, so
growth rate increases.
Increasing the temperature increases enzyme activity. - questions and answersSuggest
and explain how two environmental variables could be changed to increase the growth
rate of cells.
There is more carbon dioxide uptake therefore the rate of photosynthesis increases
resulting in more growth.
There is also more water loss via transpiration through the stomata, decreasing
photosynthesis, slowing growth. - questions and answersSuggest and explain one
advantage and one disadvantage of increased stomatal density on the growth of
tobacco plant leaves.
First heat the sample with an acid in a water bath and neutralise, then heat with
Benedict solution in a water bath for five minutes. A positive test should produce a red
precipitate. - questions and answersDescribe a biochemical test to show that raffinose
solution contains a non-reducing sugar.
Phospholipids are arranged in a phospholipid bilayer. The hydrophobic fatty acid tails
point away from the water and the hydrophilic heads attract the water. - questions and
answersExplain the arrangement of phospholipids in a cell-surface membrane.
An ester bond is formed between a glycerol and a fatty acid, producing a water
molecule in a condensation reaction. - questions and answersDescribe how an ester
bond is formed in a phospholipid molecule.
Water has a high specific heat capacity. This buffers changes in temperature, so lots of
energy is required to change the temperature. - questions and answersState and
explain the property of water that helps to prevent temperature increase in a cell.
The phagocyte is attracted to the pathogen by chemoattractants. The phagocyte binds
to the pathogen. The pathogen is engulfed and lysosomes migrate to the phagosome.
The lysosomes then release lytic enzymes which break down the pathogen. The
breakdown products are then absorbed by the phagocyte. - questions and
answersDescribe how a phagocyte destroys a pathogen present in the blood.
Cancer cells and virus infected cells. - questions and answersGive two types of cell,
other than pathogens, that can stimulate an immune response.
It joins two polypeptide chains - questions and answersWhat is the role of a disulphide
bridge in forming the quaternary structure of an antibody.
DNA in the nucleus codes for the amino acids which make up proteins. Ribosomes on
the RER then synthesise these proteins. Mitochondria produce ATP for use in protein
synthesis. The Golgi apparatus then packages and modifies proteins which are
transported to the cell surface membrane in vesicles where they fuse. - questions and
answersOutline the role of organelles in the production, transport and release of
proteins from Eukaryotic cells.
Do not include details of transcription or translation in your answer.
, There is a higher resolution / view internal structures - questions and answersGive one
advantage of viewing a biological specimen using a transmission electron microscope
compared with using a scanning electron microscope.
The diaphragm muscle contracts and external intercostal muscles contract. This causes
an increase in volume and decrease in pressure. This causes air to move down the
pressure gradient and into the lungs. - questions and answersDescribe and explain the
mechanism that causes lungs to fill with air.
The tissue doesn't contain starch and it makes the nucleus, which contains DNA,
visible. - questions and answersTwo solutions often used to stain tissues are
haematoxylin solution and iodine solution.
• Haematoxylin solution stains DNA a blue colour. • Iodine solution stains starch a
blue-black colour.
The scientist used haematoxylin solution and not iodine solution to stain the lung tissue.
Suggest why.
Free RNA nucleotides form complementary base pairs. RNA polymerase then forms
phosphodiester bonds. - questions and answersDescribe how mRNA is produced from
an exposed template strand of DNA. Do not include DNA helices or splicing in your
answer.
A triplet base sequence which codes for a sequence of amino acids. - questions and
answersDefine the term exon.
Circular DNA and plasmids are replicated, tenth cytoplasm divides producing two
daughter cells. - questions and answersDescribe binary fission in bacteria.
Increase the concentration of glucose and oxygen to increase the rate of respiration, so
growth rate increases.
Increasing the temperature increases enzyme activity. - questions and answersSuggest
and explain how two environmental variables could be changed to increase the growth
rate of cells.
There is more carbon dioxide uptake therefore the rate of photosynthesis increases
resulting in more growth.
There is also more water loss via transpiration through the stomata, decreasing
photosynthesis, slowing growth. - questions and answersSuggest and explain one
advantage and one disadvantage of increased stomatal density on the growth of
tobacco plant leaves.
