exam questions

Question 1

instead of saying “amount” of something what should you say?

Answer 1

mass or volume

Question 2

why would a dosage be calculated per unit mass?

Answer 2

takes into account different masses which allows comparison

Question 3

explain how antibodies were produced when the mice were injected with sheep red blood cells (3) (testing knowledge of humoral response)

Answer 3

1) sheep red blood cells act as antigen presenting cells/ have antigens on their surface
2) antigens are proteins which are foreign to the mice/ non self antigens
3) stimulate B cells to produce antibodies

Question 4

a newspaper suggests the data shows taking a drug will give people increased immunity. Why is this not true? (3)

Answer 4

1) response only observed in mice
2) not all disease is caused by pathogens/ cured by antibodies
3) specific disease organisms not investigated

Question 5

suggest the ways a student could improve the quality of their scientific drawing (4)

Answer 5

1) add more labels
2) no shading
3) use single lines/ no sketching lines
4) add magnification/scale bar

Question 6

the damselfly larvae is a carnivore that actively hunts prey…explain how the presence of gills adapts the damselfly to its way of life (2)

Answer 6

1) damselfly larvae will have a higher metabolic and respiratory rate as they are predators
2) so they will use up more oxygen so therefore need the adaptation of gills to obtain oxygen from water

Question 7

what is the difference between a correlation and a causal relationship?

Answer 7

causation indicates that one variable increases/ decreases as a result of the other variable

Question 8

the table below shows some features of gas exchange of a fish at rest:
vol. of O2 absorbed by the gills from each dm3 of water/ cm3: 7
mass of fish/kg: 0.4
O2 required by fish/ cm3kg-1hour-1: 90
calculate the vol. of water that would have to pass over the gills each hour to supply the O2 required by the fish. (2)

Answer 8

90/7= 12.8
12.8x0.4= 5.14
ans= 5.1

Question 9

‘the fibrous tissue reduces the elasticity of the lungs and causes the alveolar walls to thicken’
The reduced elasticity of the lungs causes breathing difficulty. Explain how. (2)

Answer 9

1) alveoli/ lungs will not inflate/ deflate fully/ reduced lung capacity
2) breathing out is no longer a passive process/ becomes particularly affected