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4D Humans influences on the
Environment
Time: 1 hour 4 minutes
Total marks available: 64
Total marks achieved: ______
Andy Todd
Q1.
The passage describes the consequences of air pollution.
Complete the passage by writing a suitable word or words on each dotted line.
(10)
The release of the gas sulfur ................................................................................... into the
atmosphere
is an example of air pollution because the gas dissolves in water in air
to form ................................................................................... rain. This rain can kill trees on land
and fish in lakes.
Another gas that pollutes the air is ...................................................................................
monoxide. This gas
combines with ................................................................................... in red blood cells and makes
it more
difficult for them to carry out their function.
Other gases that pollute the atmosphere are greenhouse gases such as
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and nitrous oxide from the burning of ................................................................................... fuels,
and ................................................................................... from the digestive system of cattle.
These gases increase the ................................................................................... effect and may
lead to a problem
known as ................................................................................... in which the air temperature may
rise.
This rise in air temperature may destroy the place where a species lives
known as its ................................................................................... .
(Total for question = 10 marks)
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Q2.
Global warming may affect the number of insect pests by increasing their ability to
produce offspring. An experiment was carried out to find out the effect of different
air temperatures on the ability of insects to produce offspring.
Five tubes were set up at an air temperature of 16 °C. Each tube contained a male
and a female insect and some food. This procedure was repeated at air temperatures
of 25 °C, 30 °C, 35 °C and 45 °C.
The insects were allowed to mate and the number of offspring they produced after
two weeks was counted.
The table shows the results.
(a) Identify the anomalous result in the table and suggest a reason for the anomaly.
(2)
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(b) The diagram shows the insect offspring collected from one of the tubes in the experiment.
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(i) Use the key to count the number of male and female offspring in this tube.
(1)
number of males .......................................................
number of females .......................................................
(ii) Which tube did these insect offspring come from?
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(c) Explain why the results in the table are reliable.
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(d) Describe the results in the table and write a conclusion for this experiment.
(3)
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(Total for question = 9 marks)
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Q3.
The data show the mean temperature in central England during thirteen periods of 25 years.
The midpoint of each period is shown.
(a) Plot the data on the grid, using straight lines to join the points.
(6)
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(b) Between which two neighbouring periods was the change in mean temperature
the greatest?
(1)
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(c) Some scientists think that the release of greenhouse gases has contributed to these
changes in temperature.
(i) Name a greenhouse gas.
(1)
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(ii) What is meant by the term greenhouse gas?
(1)
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(iii) Suggest how human activities could be responsible for the change in temperature
between 1970 and 1995.
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(Total for question = 12 marks)
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Q4.
Read the passage below. Use the information in the passage and your own knowledge
to answer the questions that follow.
(a) Name one base found in DNA (line 3).
(1)
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(b) Suggest why explants are sterilised (line 4).
(2)
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(c) Suggest why amino acids are provided in the growth medium (line 5).
(1)
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(d) What is meant by the term pathogen (line 10)?
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(e) Suggest two reasons why growers prefer to use micropropagation rather than
sexual methods of reproduction to produce good quality flowers (lines 11 to 14).
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(f ) Suggest what is meant by the term sustainable energy source (lines 19 and 20).
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(g) The destruction of habitat can lead to extinction of species.
Give three other disadvantages of deforestation.
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(Total for question = 11 marks)
Andy Todd
Q5.
A student used this apparatus to find out if nitrate ions helped plants to grow.
A young plant was grown in a solution that contained all the ions needed for growth.
A different young plant was grown in a solution that also contained all the ions
needed for growth except nitrate.
(a) (i) Suggest why the solutions have air bubbled into them.
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(ii) Suggest why the apparatus was covered in black paper.
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(b) The diagram shows the young plants after 55 days of growth.
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(i) Measure the length of the plants in mm and write your answers below.
(2)
plant grown in the solution containing all the ions
........................................................................... mm
plant grown in the solution without nitrate ions
.................................................................................. mm
(ii) Suggest how the student could make the results of the investigation more
reliable.
(1)
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(iii) Suggest two factors, not seen in the diagram, that the student should keep
the same for both plants while they are growing.
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(c) Explain the consequences of fertiliser containing nitrates polluting a river.
(6)
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(Total for question = 15 marks)
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Q6.
(a) The table describes stages in the water cycle.
Complete the table by naming or describing each stage.
The first one has been done for you.
(3)
(b) Describe the biological consequences of pollution of water by sewage.
(4)
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(Total for question = 7 marks)
Andy Todd
Q1.
This question required students to complete a passage on air pollution and most scored 9 or 10
marks. The most common errors being gas combining with oxygen in red blood cells and failing
to name methane gas produced from the digestive system of cows.
Q2.
This question presented candidates with experimental data showing the effect of
temperature on insect numbers. In (a), most were able to identify the anomalous
result and better responses suggested that this could be due to the temperature
not being at 30°C, more food being present in the tube or a particularly fecund
female. In (b), almost all candidates correctly counted the male and female flies
and identified which tube they came from. Only the best candidates gained both
marks in (c) for explaining that the results were reliable because they were close
together and repeated. In (d), many gained full credit for describing the effect of
temperature on insect numbers. Centres should remind candidates that repeating
the raw data is not describing and will not earn credit.
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Q3.
This question presented data on global temperature change over 300 years. Most
students were able to accurately plot this data. However, some students drew
the line extrapolating back to the origin when no data was available. Others
chose a scale that made plotting difficult. Many candidates were able, in (b), to
identify the two periods between which the greatest change in temperature took
place. Those candidates that examined the data carefully gained credit. Those
that just assumed the greatest change would be in recent years failed to earn
the mark. In (c) most could name a greenhouse gas and many could explain
that a greenhouse gas is one that contributes to global warming. Most could also
suggest how human activities could have contributed to the temperature change
between 1970 and 1995.
Q4.
This question this year explored the use of micropropagation in modern day biology. All the
questions were attempted by students showing that they were able to access the content of the
comprehension. Most were able to name one of the bases found in DNA though the spellings
were often rather disappointing. In part (b) many appreciated that sterilising kills bacteria that
otherwise might cause disease or have a detrimental effect on the growth of the explants. Most
students appreciated that amino acids are fundamental in the manufacture of proteins. There
were a lot of answers that gained no credit because they simply rephrased the stem of the
question stating that amino acids are needed for growth. Many students know that pathogens are
disease causing microorganisms, but many lost credit by being too vague. For example, stating
that pathogens are organisms that cause harm or illness is not sufficient. It was pleasing to note
that most were able to suggest a meaningful definition of a sustainable energy source, with most
using the phrase 'never runs out'. Some students wrote about the ecological benefits of
sustainable energy sources but this was not credited. Answers to part (g) were pleasing with
most answers making reference to leaching, soil erosion and global warming. Many had failed to
read the question carefully and wrote about the consequences of habitat destruction and
extinction.
Q5.
This question described an experiment to see if nitrate ions help a plant to
grow. In part a) the best candidates were able to suggest that oxygen
needs to be provided for respiration and to allow the roots to absorb ions by
active transport. The better candidates were also able to recognise that
keeping the apparatus covered in black paper would exclude light to prevent
photosynthesis by algae in the ion solution. Other candidates gained some
credit for reference to excluding light or preventing photosynthesis. In part
b) candidates needed to measure the length of the two plants. Most were
able to do this and the examining team allowed a range of values for each
length. The candidates who did not earn the marks were either way out with
their measurements or wrote 8.5mm. Almost all candidates could suggest
that repeating the experiment would improve the reliability of the
investigation and most could identify two factors that should be kept the
same. In part c) many candidates gained full marks for explaining how
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soluble nitrates could dissolve in rain and leach into the river leading to an
algal bloom (eutrophication). This growth would block sunlight reduce
photosynthesis and reduce oxygen levels leading to death of aquatic
animals and plants. Some candidates also went on to describe the role of
decomposers, but this was not necessary to earn full credit.
Q6.
This question examined student knowledge of the water cycle and the consequences of sewage
pollution. In part (a), most students recalled condensation and precipitation as the correct
responses to naming the stages. However, only the better students were able to offer an
acceptable description of transpiration. A surprising number believe that transpiration is the
runoff into rivers that flow to the sea, or the absorption of water by plant roots. Answers to part
(b) were poor in their construction and tested the leniency of markers in awarding credit. Whilst it
is clear that students know that sewage pollution kills fish because of oxygen depletion created
by bacterial decomposition, the way in which they express this simple idea is often so convoluted
that the marking points start to lose credibility. Marks were available to those students who also
wrote about eutrophication as a possible consequence of sewage pollution.
Q1.
Q2.
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Q3.
Q4.
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Q5.
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Q6.
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