Biology Home learning
Home learning (1)- Past paper questions
Name:
Due:
1. Scientists measured the amount of energy used by four people, A, B, C and D. The scientists
also measured the amount of energy taken in as food by each person. The chart shows the
scientists’ results.
a. (i) What was the mean amount of energy
used by D?
.....................................................................
. kJ per day
(1 mark)
(ii) The amount of energy used by D is
different from the amounts of energy used
by A, B and C.
Suggest two reasons why.
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.....................................................................
.....................................................................
.....(2 marks)
(b)
The data in the bar chart was collected over twelve months.
Which person, A, B, C or D, would gain body mass over the twelve months? Give a reason for your answer.
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............................................................................................................................... (2 marks)
(c) In the UK many people are obese. Doctors advise obese people to lose mass.
Suggest two different ways an obese person could lose mass.
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Home learning (2)- Growing bacteria
1.
Name:
Due:
Some students investigated the effect of pH on the growth of one species of bacterium.
They transferred samples of bacteria from a culture of this species to each of eight flasks. Each flask
contained a solution of nutrients but at a different pH.
After 24 hours, the students measured the amount of bacterial growth.
a)It was important that the flasks in which the bacteria grew were not contaminated with
other microorganisms.
Describe two precautions the students should have taken to prevent this contamination.
1.......................................................................................................
2.......................................................................................................
(2 marks)
(b) To see the effect of pH on the growth of the bacteria, other conditions should be kept
constant.
Suggest two conditions which should have been kept constant for all eight flasks.
1.............................................................................................................
2.............................................................................................................. (2 marks)
(c) The students wanted to find the best pH for the growth of this
species of bacterium.
(i) Use the graph to estimate the pH at which the bacteria would
grow best.
pH ..............................
(1 mark)
(ii) What could the students do to find a more accurate value for
the best pH for growth of the bacteria?
.....................................................................................................
(1 mark)
Home learning (3)- Antibiotics
Name:
1. An investigator placed paper discs containing different
concentrations of an antibiotic onto a culture of bacteria in
a petri dish. After an incubation period of two days, the
dish looked like this:
Due:
2. The concentration of the antibiotic on the
paper discs is given in the table, along with the
diameter of the circles where no bacteria are
growing.
Disc
(a) Which antibiotic disc is the most effective at
killing this strain of bacteria?
……………………………… (1 mark)
(b) Explain why there are areas around some of the
paper discs where no bacteria are growing.
..............................................................................
..............................................................................
(2 marks)
A
Concentration
of the antibiotic
in units
0
Diameter of circle
where no bacteria
are growing, in mm
0
B
2
8
C
4
14
D
6
26
E
10
26
(a) What effect does an increase in the
concentration of the antibiotic have on the
growth of the bacteria?
…………………………………………………
…………………………………………………
………………………………… (2 marks)
3. Scientists are concerned that many bacteria are developing resistance to antibiotics.
Higher
question:
Suggest
two ways by which this problem could be limited.
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........................................................................................................................ (2 marks)
Home learning (4)- Antibiotics
Name:
1. The graph shows the number of people with measles in the UK between
1940 and 2010.
Due:
a) The MMR vaccine was
introduced in 1988. Other
than measles, which two
diseases does the MMR
vaccine protect against?
1......................................
2 .....................................
(2 marks)
b. Compare how effective introducing the measles vaccine was with introducing the MMR vaccine.
Use data from the graph.
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……………………..…………………………………………………………………(3 marks)
(c) To immunise someone against measles, a small quantity of the inactive measles pathogen is
injected into the body. Describe what happens in the body after immunisation to stop a person
catching measles in the future.
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…………………………………………………………………………………………..(3 marks)