AQA AS Biology Exam Questions and Answers |Complete Solutions Graded A+ |100% Correct
Pancreatitis can lead to the release of protein-digesting enzymes into the blood. This is harmful
to the body. Suggest one reason why. They could hydrolyse/digest own proteins such as
membrane proteins/antibodies
Explain why it is necessary for humans to synthesise a large amount of ATP. 1. ATP is
unstable;
2. ATP cannot be stored / is an immediate source
of energy;
3. Named process uses ATP ;
4. ATP only releases a small amount of energy at
a time;
Adaptations of a leaf Large SA:V ratio: absorb as much sunlight as possible
Leaves are thin: short diffusion distance for gases entering
Many air spaces in spongy mesophyll: diffusion of CO2/O2
Many stomata: for gaseous exchange
Transparent cuticle and upper epidermis: let light through to the photosynthetic mesophyll
cells
Long narrow upper palisade (many cells packed in): so number of chloroplasts to absorb the
light increases
Explain why converting pyruvate to lactate allows the continued production of ATP during
anaerobic respiration. NAD regenerated/NADH oxidised to NAD. Used in glycolysis.
Explain the difference in the mean rate of respiration in soil under trees and soil NOT under
trees. Respiration higher in soil undre tree
Tree roots carry out a lot of respiration
More/there are roots under tree
, quaternary structure The fourth level of protein structure; the shape resulting from the
association of two or more polypeptide chains
starch molecule has a spiral shape, why is that important? compact so occupies small
space/tightly packed
the haemoglobin in one organism may have a different chemical structure from the
haemoglobin in another organism. describe how. different primary structure/amino
acids/different number of polypeptide chains
points on the graph have been joined with straight lines rather than with a smooth curve. why?
cannot predict/ do not know intermediate values
It would have been useful to have had a control in this investigation. Explain why To see
what would happen/ compare with no (management work)-- example / to see if numbers
changed anyway/ To show that it was not a factor;
Arteries and arterioles take blood away from the heart. Explain how the structures of the walls
of arteries and arterioles are related to their functions Elastic tissue: 1 Elastic tissue
stretches under pressure/when heart beats; 2 Recoils/springs back; 3 Evens out pressure/flow;
Muscle: 4 Muscle contracts; 5 Reduces diameter of lumen/vasoconstriction/constricts vessel; 6
Changes flow/pressure;
Epithelium: 7 Epithelium smooth; 8 Reduces friction/blood clots/less resistance;
The biologists measured the maximum diameter of each shrimp's eye. Explain why they
measured the maximum diameter. (So results) can be compared/so measurement is the
same each time/because eye is not perfectly round/uniform
Root pressure moves water through the xylem. Describe what causes root pressure. (3)
Active transport of salts into the xylem;
Pancreatitis can lead to the release of protein-digesting enzymes into the blood. This is harmful
to the body. Suggest one reason why. They could hydrolyse/digest own proteins such as
membrane proteins/antibodies
Explain why it is necessary for humans to synthesise a large amount of ATP. 1. ATP is
unstable;
2. ATP cannot be stored / is an immediate source
of energy;
3. Named process uses ATP ;
4. ATP only releases a small amount of energy at
a time;
Adaptations of a leaf Large SA:V ratio: absorb as much sunlight as possible
Leaves are thin: short diffusion distance for gases entering
Many air spaces in spongy mesophyll: diffusion of CO2/O2
Many stomata: for gaseous exchange
Transparent cuticle and upper epidermis: let light through to the photosynthetic mesophyll
cells
Long narrow upper palisade (many cells packed in): so number of chloroplasts to absorb the
light increases
Explain why converting pyruvate to lactate allows the continued production of ATP during
anaerobic respiration. NAD regenerated/NADH oxidised to NAD. Used in glycolysis.
Explain the difference in the mean rate of respiration in soil under trees and soil NOT under
trees. Respiration higher in soil undre tree
Tree roots carry out a lot of respiration
More/there are roots under tree
, quaternary structure The fourth level of protein structure; the shape resulting from the
association of two or more polypeptide chains
starch molecule has a spiral shape, why is that important? compact so occupies small
space/tightly packed
the haemoglobin in one organism may have a different chemical structure from the
haemoglobin in another organism. describe how. different primary structure/amino
acids/different number of polypeptide chains
points on the graph have been joined with straight lines rather than with a smooth curve. why?
cannot predict/ do not know intermediate values
It would have been useful to have had a control in this investigation. Explain why To see
what would happen/ compare with no (management work)-- example / to see if numbers
changed anyway/ To show that it was not a factor;
Arteries and arterioles take blood away from the heart. Explain how the structures of the walls
of arteries and arterioles are related to their functions Elastic tissue: 1 Elastic tissue
stretches under pressure/when heart beats; 2 Recoils/springs back; 3 Evens out pressure/flow;
Muscle: 4 Muscle contracts; 5 Reduces diameter of lumen/vasoconstriction/constricts vessel; 6
Changes flow/pressure;
Epithelium: 7 Epithelium smooth; 8 Reduces friction/blood clots/less resistance;
The biologists measured the maximum diameter of each shrimp's eye. Explain why they
measured the maximum diameter. (So results) can be compared/so measurement is the
same each time/because eye is not perfectly round/uniform
Root pressure moves water through the xylem. Describe what causes root pressure. (3)
Active transport of salts into the xylem;
