B1 High Demand Application style questions
(111 marks=111 minutes)
Q1.
The diagram shows one method of cloning sheep.
(a)
The fusion of the body cell from the male sheep and the egg from the female sheep is
an example of asexual reproduction.
Explain why.
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(2)
(b)
(i)
Give the gender and face colour of the cloned lamb.
Gender ..........................................................
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Face colour ...................................................
(1)
(ii)
Give the reasons for your choice.
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(2)
(Total 5 marks)
Q2.
The diagram shows how genetic engineering can be used to produce human insulin
from bacteria. Ampicillin and tetracycline are two types of antibiotic. Study the diagram
carefully and answer the questions.
Page 2
In experiments like these, some bacteria take up the plasmid (ring of DNA) containing the
insulin gene. Other bacteria fail to take up a plasmid, or they take up an unmodified plasmid
(a ring of DNA which has not been cut open and which does not contain the insulin gene).
(a)
Complete the table by putting a tick ( ) in the correct boxes to show which bacteria
would be able to multiply in the presence of ampicillin and which bacteria would be
able to multiply in the presence of tetracycline.
Bacterium can multiply in
the presence of
Ampicillin
Bacterium + plasmid with the insulin gene
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Tetracycline
Bacterium without a plasmid
Bacterium with an unmodified plasmid
(3)
(b)
The bacterium with the plasmid containing the insulin gene multiplies by cell division
to form a clone of bacteria.
Will all the bacteria in this clone be able to produce insulin? Explain your answer.
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(3)
(Total 6 marks)
Q3.
(a)
Explain, as fully as you can, how natural selection leads to evolution.
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(3)
(b)
Most penguins live in cold climates. The modern penguin best adapted for cold
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conditions is the emperor penguin.
Scientists have found fossils of a ‘giant’ penguin which they have called Icadyptes.
The diagram shows how the size of modern penguins compares with Icadyptes.
The scientists were surprised to discover that Icadyptes lived in warm seas at a time
when the Earth’s climate was much warmer than it is now.
Explain why the scientists were surprised that Icadyptes lived in warm seas.
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(2)
(Total 5 marks)
Q4.
An oak wood contained the following:
200 oak trees
150 000 primary consumers
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120 000 secondary consumers
(a)
Draw and label a pyramid of biomass for this wood. (Your pyramid does not have to
be drawn to scale.)
(2)
(b)
A scientist estimated the total amount of energy flow through each level of the
pyramid per year.
The results were:
Energy absorbed by oak trees
4 600 000 kJ per m2 per year
Energy in sugar produced by trees
44 000 kJ per m2 per year
Energy transferred to primary consumers
2 920 kJ per m2 per year
Energy transferred to secondary consumers
700 kJ per m2 per year
(i)
Calculate the percentage of the energy absorbed by the trees that is transferred
to sugar by photosynthesis. Show your working.
Answer ................................. %
(2)
(ii)
Suggest two reasons why a large proportion of the energy is not transferred
to sugar.
1 ........................................................................................................................
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2 ........................................................................................................................
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(2)
(iii)
Give three reasons why some of the energy in the primary consumers is not
passed on to the secondary consumers.
1 ........................................................................................................................
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2 ........................................................................................................................
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3 ........................................................................................................................
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(3)
(Total 9 marks)
Q5.
(a)
Some students are investigating the behaviour of a mouse. They use a large
empty box. The box has squares marked on the floor, as shown in the diagram.
(C = corner square, S = side square, I = inside square)
C1
S1
S2
S3
C2
S10
I1
I2
I3
S4
S9
I6
I5
I4
S5
C4
Ss
S7
S6
C3
They put a mouse in the empty box. They record which square the mouse is in every
minute for the next 15 minutes. The students then put a dish of food on square I2 and
repeat the observations.
They get these results.
Time
(minutes)
1
Position of
C1
mouse in
empty box
Position of
C2
mouse with
food on I2
2
3
4
5
6
7
8
9
10
11
12
13
14
15
C1
S2
C3
C3
S9
L3
C1
C1
C1
Ss
C4
C4
C1
S2
C2
C2
S5
C3
S1
C4
S1
I2
I2
C1
C1
C1
S10
C1
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(i)
Make a table to show how much time the mouse spends in the corner squares
(C), the side squares (S) and the inside squares (I) both in the empty box and
when food is present.
(4)
(ii)
Present your results as a bar chart.
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(3)
(iii)
What do the results show?
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(2)
(b)
One of the students drops a pen near the box. The mouse jumps at the noise.
Describe how the mouse would hear the sound of the dropped pen.
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(2)
(Total 11 marks)
Q6.
The diagram shows the flow of energy through 1 m2 of an ecosystem.
Unit in each case is kJ per m2 per year
KEY
A producers
B primary consumers
C secondary consumers
D tertiary consumers
E heat transfer to environment
F detritus feeders and decomposers
(a)
(i)
Name the process in which green plants transfer solar energy into
chemical compounds.
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(1)
(ii)
Name the process in living organisms which results in the transfer of heat to the
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environment.
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(1)
(b)
Tertiary consumers receive energy from secondary consumers.
(i)
Calculate the amount of heat energy which tertiary consumers transfer to the
environment as a percentage of the energy received from secondary
consumers. Show your working.
Energy transferred ............................... %
(2)
(ii)
Primary consumers transfer a low percentage of their energy intake to the
environment as heat. Tertiary consumers transfer a much higher percentage of
their energy intake to the environment as heat.
The tertiary consumers are mainly mammals and birds.
The primary consumers are mainly insects and molluscs.
Explain why mammals and birds lose a greater percentage of their energy
intake to the environment as heat than do insects and molluscs.
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(2)
(Total 6 marks)
Q7.
The diagram below shows the mass of carbon involved each year in some of the
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processes in the carbon cycle.
(a)
Complete the equation for plant respiration.
(2)
(b)
(i)
Calculate the mass of carbon removed from the atmosphere each year. (Show
your working.)
Answer .......................... billion tonnes
(1)
(ii)
Calculate the percentage of this total which is removed by the photosynthesis of
land plants. (Show your working.)
Answer ...................................... %
(2)
(iii)
Calculate the net gain of carbon by the atmosphere in one year. (Show your
working.)
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Answer ........................... billion tonnes
(2)
(Total 7 marks)
Q8.
Oestrogen, luteinising hormone (LH) and follicle stimulating hormone (FSH) work
together to coordinate the menstrual cycle. A woman will be infertile if her pituitary gland
does not release enough follicle stimulating hormone (FSH).
Explain how injections of FSH could increase her chances of having a baby.
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(Total 3 marks)
Q9.
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.
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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 ..................................................................................................................................
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2 ..................................................................................................................................
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(2)
(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)
(c)
The graph shows the results of the investigation.
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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)
(ii)
What could the students do to find a more accurate value for the best pH for
growth of the bacteria?
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(1)
(Total 6 marks)
Q10.
(a)
Describe, as fully as you can, how a human foetus gets rid of the carbon dioxide
produced during respiration.
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(3)
(b)
The female menstrual cycle is controlled by a number of hormones. The graph below
shows the concentrations of four of these hormones at different times during the
menstrual cycle.
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The functions of the four hormones include:
FSH – stimulates the development of immature cells into eggs in the ovary.
LH – stimulates the release of the mature egg cell.
Oestrogen – stimulates production of LH, but inhibits FSH production.
Progesterone – inhibis production of both LH and FSH.
Use this information to explain as fully as you can:
(i)
how the concentration of oestrogen can affect and control the development and
release of an egg during the monthly cycle;
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(3)
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(ii)
why progesterone continues to be produced throughout pregnancy.
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(3)
(c)
Explain, as fully as you can, how one or more of these hormones could be used to
treat infertility.
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(3)
(d)
A hormone called mifepristone is used in low doses as a female contraceptive. Higher
doses can be used to induce an abortion. As a consequence mifepristone is often
referred to as ‘the morning-after pill’. The use of mifepristone is currently tightly
controlled by the medical profession.
Evaluate the benefits and problems which might arise from making this hormone
more freely available.
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(4)
(Total 16 marks)
Q11.
The vole is a small, mouse-like animal. Voles found on some cold islands to the north
of Scotland are much larger than voles found in warmer areas such as southern France.
Explain how natural selection may have caused the northern voles to be larger in size.
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(Total 5 marks)
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The diagram shows the flow of energy through a forest. The figures are in kilojoules of
energy per square metre per year.
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(a)
What percentage of the energy in the trees is passed on as food for the carnivores?
Show clearly how you work out your final answer.
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................................... per cent
(2)
(b)
Give three reasons why so little of the energy in the trees is passed on to the
carnivores.
1 ...................................................................................................................................
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2 ...................................................................................................................................
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3 ...................................................................................................................................
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(3)
(Total 5 marks)
##
In women, two hormones control ovulation (the release of eggs from the ovaries). The
drawing shows a monitoring machine which women can use to measure the amounts of the
two hormones. A test stick is dipped in the woman’s urine each morning, then placed in a
slot in the machine.
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(a)
The machine monitors the levels of two hormones.
(i)
What is a hormone?
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(1)
(ii)
How are hormones transported around the body?
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(1)
(b)
A woman is unlikely to become pregnant if she has sex on the days when the
machine shows a green light during the test. Use information from the drawing to
suggest why.
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(1)
(Total 3 marks)
Q14.
Influenza is a disease caused by a virus.
(a)
Explain why it is difficult to treat diseases caused by viruses.
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(2)
(b)
In some years there are influenza epidemics.
The graph shows the death rate in Liverpool during three influenza epidemics.
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(i)
The population of Liverpool in 1951 was approximately 700 000.
Calculate the approximate number of deaths from influenza in week 4 of the
1951 epidemic.
Show clearly how you work out your answer.
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Number of deaths ..............................
(2)
(ii)
In most years, the number of deaths from influenza in Liverpool is very low.
Explain, in terms of the influenza virus and the body’s immune system, why
there were large numbers of deaths in years such as 1918 and 1951.
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(3)
(Total 7 marks)
Q15.
The photograph shows a snake eating a toad.
Cane toads were first introduced into Australia in 1935. The toads contain toxins and most
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species of Australian snake die after eating the toad.
The cane toad toxin does not affect all snakes the same way. Longer snakes are less affected by
toad toxin.
Scientists investigated how red-bellied black snakes had changed in the 70 years since cane
toads were introduced into their area. They found that red-bellied black snakes had become
longer by around 3 – 5 %.
Suggest an explanation for the change in the body length of the red-bellied black snakes since the
introduction of the cane toads.
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(Total 4 marks)
Q16.
Read the passage about IVF (in-vitro fertilisation) and embryo-splitting.
“IVF is not as successful as we would like it,” says scientist Michael Tucker. “On
average, only one in five or one in six of all the embryos that we generate in the
IVF lab will develop as far as full-term delivery as a baby.”
“There is a way to perhaps double those odds. A new, identical embryo is split off
from the original embryo made in the IVF lab.”
“What we are really doing is creating an identical twin,” says scientist Dr Hilton
Kort.
“And that’s what happens in nature every day. Cloning is creating a replica of a
person or an animal.”
(a)
Explain why the two embryos will develop into identical twins.
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(2)
(b)
Explain why the embryos are not clones of their parents.
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(2)
(c)
The scientists want to develop this technique, but are afraid to do so because public
opinion might be against the technique.
Suggest an explanation for this.
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(1)
(Total 5 marks)
Q17.
The photograph shows a sand gazelle.
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The sand gazelle lives in the Arabian Desert where temperatures often reach 45 °C.
(a)
The sand gazelle feeds only at dawn and at dusk. At other times it stays in the shade.
Suggest how this helps the animal to conserve water.
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(2)
(b)
During the dry season, the sand gazelle’s liver and heart shrink in size. This reduces
the amount of oxygen that the body needs.
Suggest how needing less oxygen helps the animal to conserve water.
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(2)
(Total 4 marks)
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Q18.
The photograph shows a Crossbill.
A Crossbill feeds by using its bill (beak) to force apart the scales on conifer cones. It then
uses its tongue to extract the seeds. If the bill is clipped it grows back again.
Scientists were interested in the evolution of the bill of the Crossbill.
In an investigation, they clipped the bills of several Crossbills so that their bills no longer
crossed.
They observed that Crossbills with clipped bills took much longer to get seeds.
Use information from the investigation to suggest an explanation for the evolution of the bill
in the Crossbill.
In your explanation, use the ideas of selection, competition and mutation.
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(Total 4 marks)
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M1.
(a)
there was no mixing of genes / genetic material
1
because the nucleus was removed from the egg cell before fusion
1
(b)
(i)
male and
white-faced
both required
1
(ii)
because the genetic material / genes
1
comes from the white-faced male only
1
[5]
M2.
(a)
Ampicillin
Tetracycline
–
–
–
accept blank or cross or –
1st: mark by rows to maximum 3 marks
2nd: if no marks by rows, mark by columns to maximum 1 mark
table completely blank = 0 marks
3
(b)
1st: Yes (no mark)
if ‘no’ - read on for logical argument e.g. loss of plasmid or
gene mutation
2nd: all formed from same original cell
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must be one cell i.e. bacterium
1
by asexual reproduction / no fusion / not sexual
allow reference to ‘mitosis’
1
offspring cells are genetically identical or
all have a copy of the insulin gene / of the plasmid
1
[6]
M3.
(a)
variation / mutation
1
individuals with characteristics most suited to environment
survive
allow survival of the fittest
1
genes passed to next generation or these individuals reproduce
1
(b)
any two from:
•
similar in size to Emperor penguin or bigger than all
penguins
•
large size is adaptation to cold climate
•
since less heat loss per unit of body volume or smaller
surface area / volume ratio
2
[5]
M4.
(a)
levels in correct order
sizes correct
for 1 mark each
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2
(b)
(i)
working
0.96% (correct answer = 2)
for 1 mark each
2
(ii)
2 of e.g.
heat up leaves
absorbed by non-photosynthetic parts
transmitted through leaves
any 2 for 1 mark each
2
(iii)
3 of e.g.
respiration of primary consumers
movement of p.c.
waste from p.c.
repair/growth of p.c.; heat losses to
surroundings
any 3 for 1 mark each
3
[9]
M5.
(a)
(i)
counting empty 10, 4, 1 and correctly placed in table counting with food
9, 4, 2 and correctly placed in table
table with three columns and correct headings
for 1 mark each
4
(ii)
reasonable scales plots all correct all labels present
for 1 mark each
3
(iii)
e.g. mouse spends most of its time in the corners whether or not food is
present in middle
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for 1 mark each
2
(b)
vibration/sound receptors in ear ‘detect’ sound impulses/electrical signals to brain
for 1 mark each
2
[11]
##
(a)
(i)
photosynthesis
for 1 mark
1
(ii)
respiration
for 1 mark
1
(b)
(i)
96 × 100 / 120
gains 1 mark
= 80%
gains 2 marks
2
(ii)
mammals and birds maintain constant body temperature,
this is usually higher than that of the environment therefore heat lost
for 1 mark each
2
[6]
M7.
(a)
glucose/sugar water
for 1 mark each
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2
(b)
(i)
204
for 1 mark
1
(ii)
49 gains 2 marks
(incorrect answer, but correct method gains 1)
2
(iii)
3 gains 2 marks
(incorrect answer, but correct method gains 1)
2
[7]
M8.
any three from:
FSH stimulates growth / maturing of follicle(s) / eggs
FSH stimulates oestrogen release
oestrogen stimulates development of uterus lining
oestrogen stimulates LH release / production
LH stimulates ovulation / egg release
[3]
M9.
(a)
•
any two from:
sterilise / kill microorganisms
ignore ‘cleaning’ / ‘disinfect’
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ignore ‘germs’
•
method of sterilisation eg apparatus / media sterilised in oven / autoclave
allow pressure cooker / boiling water
•
pass flask mouth / pipette tip / loop / test tube mouth through flame
•
work near a flame
•
minimise opening of flask / test tube or hold non-vertical
allow idea of sealing / covering or prevent entry of air
2
(b)
any two from:
•
temperature
ignore references to time / type of bacterium
•
concentration / amount of nutrients / ions
•
type of nutrient
•
volume / amount of solution
•
amount of bacteria added
•
agitation or amount of oxygen
2
(c)
(i)
7.5
accept in range 7.4 – 7.6
1
(ii)
use more pH values around / close to pH 7.5 / between 7 and 8
1
[6]
M10.
(a)
moves from foetal blood to mothers blood via placenta
for 1 mark each
3
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(b)
(i)
3 of e.g.
rising levels of oestrogen
result in an increased LH level when LH level peaks
egg release stimulated
any 3 for 1 mark each
3
(ii)
3 of e.g.
continues to inhibit FSH production and to inhibit LH production
so that no eggs are matured or released
Because of danger to later conceived fetus if 2 develop in uterus
any 3 for 1 mark each
3
(c)
3 of e.g.
FSH could stimulate eggs to mature in woman whose own level of FSH too low
LH could stimulate egg release where woman’s own LH production depressed by
oestrogen
any 3 for 1 mark each
3
(d)
maximum two benefits e.g.
prevents unwanted pregnancy when mother’s physical health at risk
or when mental health at risk
or following e.g. rape
maximum two problems e.g.
involves killing ‘foetus’ rather than preventing gametes meeting
may lead to irresponsible attitude to sexual behaviour
reference to ethical/religious attitudes
for 1 mark each
4
[16]
M11.
any five from:
•
genetic variation exists in a population or
variation caused by mutation / change in gene / in DNA
•
larger voles have smaller
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or have more fat
‘they’ accept as larger voles
•
larger voles lose less heat / are better insulated or more energy stored
•
larger voles survive
•
larger voles breed
•
larger voles pass on (beneficial) gene / allele / mutation / DNA
ignore characteristic
[5]
M12.
(a)
1.67 / 1
accept 1.6 to 1.7
ignore working or lack of working
for 1 mark
2
(b)
any three from:
deduct only 1 mark for any mention of in carnivore
lost as heat or keeping body warm
lost in metabolic functions is not enough
lost in respiration
do not accept ‘used for respiration
movement
not eaten parts or individuals / non-edible parts / dead leaves / wood /
bones / faeces / urine
ignore ‘waste’
ignore references to growth / reproduction
3
[5]
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M13.
(a)
(i)
idea that chemical / substance that controls / co-ordinates bodily process
for 1 mark
reject chemical messenger unless qualified as above,- reject
ref. to one hormone only
1
(ii)
in the blood
for 1 mark
1
(b)
idea that
device indicates / detects low levels / no hormones / relevant hormone
for 1 mark
1
[3]
M14.
(a)
any two from
•
live inside / infect body cells
•
difficult for drugs to enter (body) cells / drug would kill (body) cell
•
antibiotics ineffective against viruses
•
viruses mutate frequently
2
(b)
(i)
420
correct answer with or without working
if answer incorrect evidence of ‘number of deaths’ × 7 or 60
seen gains 1 mark
ignore 6 000 000
2
(ii)
any three from:
•
virus / flu mutates
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•
people no longer / not immune
ignore resistance
•
white blood cells / memory cells / immune system do not
recognise virus
•
relevant reference to antibodies / antigens
•
current vaccine ineffective or no vaccine available then
or takes time to develop new vaccine
allow no tamiflu / anti-viral drugs
•
conditions less hygienic / lack of hygiene
•
people in poor health (following world wars)
allow people had ‘weak’ immune system
3
[7]
M15.
any four from
•
mutation
do not accept ‘had to mutate / decided to mutate’
•
produces longer snake or there is variation in snake length
do not accept ‘had to adapt and became longer’
•
longer snake less susceptible to toxin or longer snake survives
•
survivors reproduce
•
gene passed to next generation
allow characteristic passed to next generation
[4]
M16.
(a)
have identical genes / chromosomes / genetic material
1
since asexual reproduction
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accept mitosis
1
(b)
mixture of genes / chromosomes / genetic material from two parents
accept meiosis
1
sexual reproduction / fusion of gametes
1
(c)
public misunderstand technique as cloning or worried about large numbers
of clones or moral / ethical / religious issues or unnatural process or scientists
must not play god or technique may lead to embryo death
do not allow mark for embryos lost
1
[5]
M17.
(a)
stays cool
ignore shade
1
less sweat
1
(b)
any two from:
•
breathing rate less
•
less water lost via breath
less can be implied
•
less water from respiration
2
[4]
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M18.
any four from:
max two marks for a Lamarck explanation
•
mutation produced a bird whose bill was crossed
do not allow birds decide to mutate
•
birds compete for food / seeds
•
mutant crossbill able to obtain food faster / easier / more successfully
•
selected for or more likely to survive
•
reproduce / mate / breed / produce offspring
[4]
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