Author: Mrs S McDonald
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Keswick School

Total:
Q1.Imatinib is a drug used to treat a type of cancer that affects white blood cells. Scientists investigated the rate of uptake of imatinib by white blood cells. They measured the rate of uptake at 4°C and at 37°C. Their results are shown in the table.
 
| | Mean rate of uptake of imatinib into cells / μg per million cells per hour
| Concentration of imatinib outside cells / μmol dm^–3 | 4°C | 37°C
| 0.5 | 4.0 | 10.5
| 1.0 | 10.7 | 32.5
| 5.0 | 40.4 | 420.5
| 10.0 | 51.9 | 794.6
| 50.0 | 249.9 | 3156.1
| 100.0 | 606.9 | 3173.0
(b)     Calculate the percentage increase in the mean rate of uptake of imatinib when the temperature is increased from 4°C to 37°C at a concentration of imatinib outside the cells of 1.0 μmol dm^−3 .
Give your answer to one decimal place.

 
Answer .....................................
(2)

Q2.        (b)     A dialysis machine contains artificial membranes which enable urea to be removed from the blood of a person with kidney failure. The diagram shows a dialysis machine.

(iv)  Blood flows through the dialysis machine at a rate of 200 cm^3 per minute.
Calculate the total volume which passes through the machine in 5 hours.
Give your answer in dm^3 and show your working.

 
 
Answer .................................... dm^3
(2)
Q3.          Read the following passage.
Human milk contains all the nutrients a young baby needs in exactly the right
proportions. It is formed in the mammary glands by small groups of milk-producing cells.
These cells absorb substances from the blood and use them to synthesise the lipids,
carbohydrates and proteins found in milk. Milk-producing cells are roughly cube-shaped
5     and have a height to breadth ratio of approximately 1.2 : 1.
The main carbohydrate in milk is lactose. Lactose is a disaccharide formed by the
condensation of two monosaccharides, glucose and galactose. (A molecule of galactose
has the same formula as a molecule of glucose – the atoms are just arranged in a different
way.)
10   Lactose is synthesised in the Golgi apparatus and transported in vesicles through the
cytoplasm. Because lactose is unable to escape from these vesicles, they increase in
diameter as they move towards the plasma membrane. The vesicle membranes fuse with
the plasma membrane and the vesicles empty their contents out of the cell.
Use the information from the passage and your own knowledge to answer the following questions.
(a)     (i)      The breadth of a milk-producing cell is 26 µm. Calculate the height of this cell.

Height = .......................... µm
(1)

Q4.   (a)     Dietary recommendations are that lipid intake should make up 30% of energy intake. The recommended energy intake for most women aged 19-49 is 8100 kJ day^–1.The energy content of lipid is 37.8 kJ g^–1. Calculate the recommended lipid intake per day for these women. Show your working.

Answer ................................................... g
(2)

Q5. One hypothesis for the cause of cancer of the colon (large intestine) is that Clostridium bacteria present in the gut can convert bile steroids into cancer-causing substances.
(b)     The concentrations of bile steroids and numbers of Clostridium bacteria were measured in people with colon cancer and in controls without colon cancer. The table shows the results.
 
Concentration of bile steroids | Number of Clostridium bacteria | Percentage of cancer patients | Percentage of controls | P

high
high
low
low

high
low
high
low

76
13
7
4

9
8
34
49

<0.01 <0.01 <0.01 <0.01

A statistical test showed there was a significant difference between the cancer patients and the controls in each of the four categories.
(i)      Explain how the results could be used to support the hypothesis that Clostridium bacteria convert bile steroids into substances which cause colon cancer.
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(2)

Q6.          S       A medical officer investigated the effectiveness of five different types of influenza vaccine. A total of 1350 people agreed to be vaccinated. The medical officer divided these into five groups. The number who suffered from influenza in the following year was recorded. The results are shown in the table.
 
| Number of people vaccinated
Type of influenza vaccine | Suffered from influenza | Did not suffer from influenza | Total | Proportion suffering from influenza
I | 43 | 237 | 280 | 0.15
II | 52 | 198 | 250 | 0.21
III | 25 | 245 | 270 | 0.09
IV | | | 260 | 0.18
V | 57 | 233 | 290 | 0.20

(a)     Complete the spaces in the table for the people vaccinated with type IV vaccine.

 
(1)

(b)     The medical officer used a statistical test to assess the effectiveness of the five different vaccines.
(i)      What would be the null hypothesis?
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(1)

(ii)     The statistical test gave a probability of less than 0.05. What conclusion can be drawn from this?
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(1)

Q7.(b)     The chart shows the actions of the atria and the ventricles during a complete cardiac cycle. Different stages have been given letters and a time scale added.
 
| Stage
| A | B | C
Atria | Contracting | Relaxing
Ventricles | Relaxing | Contracting | Relaxing
0.0             0.1           0.2          0.3           0.4          0.5         0.6        0.7           0.8
Time / seconds

(ii)     The heart beats for one minute at the rate shown by the chart. Calculate the total time the ventricles are relaxed during one minute. Show your working.
Answer ....................................... seconds
(2)
(Total 6 marks)
 Q8.          Some enymes digest protein. They hydrolyse the peptide bonds between amino acids. The extent to which a protein is digested is called the degree of hydrolysis (DH). The DH value may be calculated from the equation:

(a)     (i)      A protein molecule contains 151 amino acids. What is the total number of peptide bonds in this molecule?
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(1)

(ii)     A molecule of this protein is digested. The DH value of the digested protein is 18. Calculate the number of peptide bonds that have been hydrolysed.

 
Answer ......................................
(1)

(b)     What would be the DH value of a protein if it were completely hydrolysed to amino acids? Explain how you arrived at your answer.
DH value ......................................................................................................
Explanation ..................................................................................................
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(2)

Q9.          (a)     Whooping cough is a childhood respiratory disease caused by a bacterium.
The graph shows the incidence of whooping cough in Central Europe from 1969 to 1999.

(i)      Calculate the percentage change in the incidence of whooping cough from 1982 to 1999. Show your working.

 
Answer ............................................
(2)

Q10.  The drawing shows an electron micrograph of parts of epithelial cells from the small intestine.

(b)     (i)      The scale bar on this drawing represents a length of 0.1μm. Calculate the magnification of the drawing. Show your working.

Magnification .............................................
(2)

Q11 (b)     The table shows the number of cases of tuberculosis in different regions of England between 2000 and 2005
 
Region | Number of cases of tuberculosis per 100 000 of the population
| 2000 | 2001 | 2002 | 2003 | 2004
East Midlands | 10.6 | 11.1 | 11.9 | 7.9 | 9.9
West Midlands | 13.7 | 13.1 | 14.9 | 15.0 | 16.2
North East | 5.7 | 7.7 | 6.4 | 6.1 | 6.7
North West | 10.0 | 10.0 | 9.4 | 9.0 | 9.3
South East | 6.1 | 6.6 | 7.3 | 7.4 | 7.3
South West | 4.6 | 4.0 | 4.8 | 4.5 | 5.3

(ii)     Calculate the percentage increase on the number of cases of tuberculosis in the south west region of England from 2000 to 2004. Show your working.

 
Answer................................................
(2)
Q12.          Seals are mammals. They have lungs and must breathe air. They can dive and remain under water for a long time. The table shows the flow of blood to the lungs and to the diaphragm in a seal when it is on land and when it is under water. 
 
Organ | Blood flow / cm^3 min^–1 g^–1
| On land | Under water
Lungs | 0.88 | 0.52
Diaphragm | 0.21 | 0.02

(c)     Calculate the percentage by which blood flow to the lungs is reduced when a seal is swimming under water. Show your working.

 
Answer ............................................
(2)

Q13.          Moulds belong to a group of organisms called fungi. When mould is examined with a microscope it is seen to consist of long, colourless threads called hyphae.
A student investigated the growth of fungal hyphae. The diagram shows part of a hypha seen under a microscope at the beginning of a lesson and again at the end of the lesson.

(b)     (i)      By how much had the hypha grown during the lesson? Show your working.

 
Answer: ........................... µm
(2)

(ii)     Explain how you could use your answer to calculate the rate of growth of this hypha.
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(1)

Q14.         (b)     Cylinders of potato were cut using a cork borer. Their initial lengths were measured.  Each cylinder was then put in a different concentration of sucrose solution for 12 hours. The graph shows the changes in length of the potato cylinders in the different sugar solutions.

(ii)     The initial length of the potato cylinder in the solution of concentration 0.1 mol dm^–3 was 90 mm. Calculate its final length. Show your working.

 
Final length = .................................... mm
(2)

Q15.          Read the following passage.
Campylobacter jejuni is a bacterium. It is one of the commonest causes of diarrhoea
in humans. The illness that it causes does not usually last very long and many sufferers
do not even go to the doctor. The only treatment required is the use of oral rehydration
solutions to replace the water lost by diarrhoea. In 1998, laboratory tests confirmed
5       60 000 cases of diarrhoea caused by this bacterium in the UK. The bacterium was
         more frequently found in males than in females with a ratio of 1.5 : 1.
In rare cases, the nervous system may be affected. Scientists are now beginning to
understand the cause of this. Sugars in the antigens on the surface of the bacteria are identical to some of the sugars on the surface of nerve cells. Antibodies produced against the bacteria may therefore attack the body’s nerve cells. There can be serious problems if this leads to paralysis of the diaphragm. Breathing difficulties result and the patient may die.

(ii)     Calculate the number of cases of diarrhoea confirmed as being caused by Campylobacter jejuni in men in 1998.

 
Answer ..........................................
(1)

Q16.          (c)     Giardiasis is one of the main causes of diarrhoea in the USA. It is usually transmitted by drinking contaminated water. The bar chart shows the number of cases of giardiasis in one state of the USA during one year.

(i)      Calculate the percentage increase in the number of cases of giardiasis from January to August. Show your working.

 
Answer ......................................
(2)

Q17.          The diagram shows a cholera bacterium. It has been magnified 50 000 times.

(d)     Calculate the actual width of the cholera bacterium between points B and C.
Give your answer in micrometres and show your working.

 
.................................. µm
(2)

Q18.          The diagram shows an epithelial cell from the small intestine.

(b)     This diagram shows the cell magnified 1000 times. Calculate the actual length of the cell between points P and Q. Give your answer in µm. Show your working.

 
 
Answer ...................................... µm
(2)

Q19.Students investigated the effect of different concentrations of sodium chloride solution on discs cut from an apple. They weighed each disc and then put one disc into each of a range of sodium chloride solutions of different concentrations. They left the discs in the solutions for 24 hours and then weighed them again. Their results are shown in the table.
 
| Concentration of sodium chloride solution / mol dm^–3 | Mass of disc at start / g | Mass of disc at end / g | Ratio of mass at start to mass at end
| 0.00 | 16.1 | 17.2 | 0.94
| 0.15 | 19.1 | 20.2 | 0.95
| 0.30 | 24.3 | 23.2 | 1.05
| 0.45 | 20.2 | 18.7 | 1.08
| 0.60 | 23.7 | 21.9 |
| 0.75 | 14.9 | 13.7 | 1.09

(a)     (i)      Calculate the ratio of the mass at the start to the mass at the end for the disc placed in the 0.60 mol dm^–3 sodium chloride solution. (1)