UNIVERSITY OF MALTA
THE MATRICULATION CERTIFICATE EXAMINATION
ADVANCED LEVEL
BIOLOGY
May 2007
EXAMINERS’ REPORT
MATRICULATION AND SECONDARY EDUCATION CERTIFICATE
EXAMINATIONS BOARD
AM EXAMINERS’ REPORT MAY 2007
AM Biology
May 2007 Session
Examiners’ Report
Part 1: Statistical Information
Table 1 shows the distribution of grades awarded in May 2007.
Table1: Grades awarded in May 2007
Grade
A
B
C
D
E
F
Abs
Total
Number
50
100
132
94
107
132
23
638
% of Total
7.8
15.7
20.7
14.7
16.8
20.7
3.6
100%
Part 2: Comments regarding performance
2.1
General Comments
The following report has been compiled from separate documents submitted by members of the
Examination Board and by markers of the examination scripts in question. It represents an appraisal of
the performance of candidates taking the Matriculation Certificate examination in biology (advanced
level) in May 2007.
Comments on each of the questions set are given below. On a more general level, a number of points
should be stressed:
1. The level of English (both in terms of grammar and spelling) was poor and hardly up to the standard
of an examination at Advanced Level. In a number of cases, the inability of candidates to express
themselves made their answers unintelligible.
2. Most candidates are uncomfortable with questions that require some thought and there appears to be a
general inability to apply learnt knowledge to novel situations. Candidates’ general performance in
questions that required straightforward regurgitation of memorised facts was satisfactory.
3. Examiners feel it should be emphasized that A-level biology requires an appropriate standard of
literacy, which includes specialist vocabulary associated with learning outcomes. There was
evidence from the responses given to certain questions that students did not fully understand the text,
nor the questions being asked, and instead answered the questions they assumed were being asked.
Additionally, candidates are discouraged from using fancy English terms whose meaning is not clear
to them. The careless misuse of biological terms (e.g. dichotomous instead of dicotyledons, cisternae
instead of cristae, secretory instead of excretory, tracheids instead of tracheoles) was not uncommon.
4. The general standard of spelling, particularly of biological terms continues to disappoint.
5. The examiners were pleased to see that the majority of candidates made considerable effort to present
their answers in a clear and legible manner. Examiners tried hard to decipher particularly unclear
hand-writing but the risk to the candidate is obvious.
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AM EXAMINERS’ REPORT MAY 2007
6. The examiners were pleased to see that some candidates prepared an essay plan that suggested that
candidates have acted on comments from previous reports.
7. Despite this, however, it is still evident that a significant number of students find difficulty planning
an essay and a number of them also find great difficulty in writing coherent paragraphs in English.
Perhaps an intervention that could help in essay writing is to force students to convert information
from bullet points to prose. This could help the weaker students build up the skills of expression prior
to producing totally free response answers.
8. It is strongly emphasized that diagrams should be an integral part of essay answers; however these
should always be properly annotated.
9. Candidates generally showed a lack of understanding of field techniques and lack of skills for
biological drawing.
10. Although students perform experiments in the lab, the underlying concept often seems not to have
been understood in the first place.
11. Candidates are not always aware that the marks available for the questions should be reflected in their
responses.
12. Overall, the standard in Paper 2 was very similar to that of previous years. As anticipated, Questions 1
and 2 again proved to be the major discriminators; however it was worrying to see that even more
able candidates found these questions rather inaccessible.
13. It was unfortunate to realize that students taking A-level biology are as vague about their knowledge
of global warming as the layman. Cataclysms and a rollercoaster of emotions were the mainstay of
answers to Question 8. As expressed earlier on, students at this level should be using specialist
vocabulary and concepts to explain phenomena which concern our planet and our well-being.
2.2
Specific Comments
Paper 1
Question 1: Viruses
Quite a number of candidates confused viruses with Monera. Several candidates suggested that
bacteriophages are bacteria and several were not aware of the nature of retroviruses.
Question 2: Genetics
The first parts of the question (2.1 & 2.2) generally presented no difficulties to candidates, although a
proportion of them did not know how to work out these calculations correctly. Questions 2.3 & 2.4
presented more difficulty to candidates, since, although the basic Hardy-Weinberg Equilibrium equation
was often given correctly, the correct calculation of p2 and q2 was often not done, and candidates often
assumed that p2 & q2 were equivalent to the answers obtained in 2.1 and 2.2, which was not the case. This
was most evident in question 2.4, which the majority of candidates answered incorrectly. Question 2.5
was answered correctly by most candidates. A plausible answer to question 2.6 was only very rarely
given, and it seemed that most candidates did not understand what the question what after. It was apparent
that the candidates either did not make the connection between the fact that homozygosity does not
protect against kuru and yet homozygous women who had practised cannibalism were still alive, or else
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AM EXAMINERS’ REPORT MAY 2007
they tried to give an answer which was too complicated, when in fact the expected answer was very
simple and logical.
Question 3: bST
Although this question was quite straightforward, a substantial number of candidates obtained less than
50% of the marks. In question 3.4, the technique for producing recombinant bST was often inaccurately
or incompletely given, and a considerable number of candidates thought that producing recombinant bST
meant producing recombinant cows, thus leading also to incorrect answers for question 3.5. In addition, a
common omission made by candidates was that they made no mention of the fact that bST is found
naturally in cows’ milk in trace amounts when they gave trace contamination of milk by bST as their
answer to question 3.5.
Question 4: Hormones
Candidates struggled greatly with this question, and it was evident that often answers were being created
where these were not known by the student. It was clear that the subject being tested was not one which
candidates had complete command over, and in most of the papers, the sources, stimuli or functions of the
hormones being mentioned were not known or given incorrectly.
Question 5: Nervous system
Question 5.1 was in general answered correctly, although most candidates lost marks for not identifying
the neuromuscular junction as a synapse. Question 5.2 presented difficulty to candidates, and very few
obtained full marks for this. A substantial number of candidates either described how an action potential
actually occurs or else the sliding filament mechanism, which were not the correct answers to the
question, and even when the correct answer was given, minor omissions or mistakes led to deduction of
marks. Questions 5.3 and 5.4 were often correctly answered, although candidates lost ½ mark for not
describing the function of acetylcholinesterase in breaking down acetylcholine.
Question 6: Moss life cycle
Quite a few candidates could not explain Alternation of Generations.
Question 7: Dissociation curves for oxyhaemoglobin
Candidates obtained relatively poor marks in this question. Very few candidates explained the curve from
a physiological aspect.
Question 8: Biomolecules
Many candidates lacked any skills of inference – these answers are not typically given in class notes but
are basic to sound knowledge of biology.
Question 9: Endosymbiont theory
Most candidates fared badly in the parts of the question requiring inference. Very few candidates gave a
correct answer to question 9.5.
Question 10: Eukaryotic flagellum
This question was answered correctly by a large number of candidates, with most candidates obtaining 4
out of the maximum of 5 marks. Common mistakes, however, included identifying the organelle as a
cilium, not a flagellum (in question 10.1) or else stating that it could be both. In addition, candidates
struggled with identifying a second function of the organelle in question 10.2. Question 10.4 was often
correctly answered if the answer to question 10.1 was given correctly. However, if the organelle was
identified as a cilium, then this mistake was often carried over to question 10.4.
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AM EXAMINERS’ REPORT MAY 2007
Paper 2
Question 1: comprehension exercise
1.1 Acceptable definitions were given by most candidates, although candidates who failed to mention that
the host is harmed or does not benefit from the relationship were not awarded full marks.
1.2 A significant majority of candidates did not secure full marks in this question because they did not
mention that obligate brood parasites are unable to build their own nests.
1.3 Very few candidates realised that the egg abandoner is free to mate and to use saved energy to
produce more eggs.
1.4 Despite its seemingly straightforward nature, only a small minority answered this question correctly.
Many suggested that the magpie would become extinct.
1.5 The majority of candidates failed to understand the context of the question. A few candidates also
suggested that cowbirds enjoy company, that is why they have two nestmates! Hardly any of the
candidates realized that the cowbird’s strategy is a ‘winner takes most’ situation.
1.6 Several said that competition was increasing.
1.7 Several candidates realised that the number of offspring would increase but few mentioned that
polygyny could only be achieved because parental care is not necessary thus allowing females
promiscuous matings.
1.8 Again, this question was misunderstood. The majority of candidates suggested that the cuckoo and the
cowbird have adopted different strategies so that they reduce interspecific competition even though the
two species are geographically isolated!
1.9 This question was totally misunderstood and a wide range of irrelevant answers were given.
1.10 Again, this question was misunderstood. Most commonly, candidates spoke of the duck’s ability to
adjust their egg laying according to the number of parasitic eggs added to the clutches. The information to
look out for here was in lines 52 and 53 of the text, which clearly state that Goldeneye ducks are faithful
to their birth place for use as nesting sites and that they also have precocial hatchlings. By being faithful
to their birth place, sisters or mothers and daughters would tend to nest in the same area, therefore the
host often would be rearing young carrying copies of the same genes. This would reduce selection
pressures on the hosts to evolve defences against parasitism. Additionally, precocial hatchlings can lessen
the host's burden when caring for the young of parasites since they are already covered in down at birth.
1.11 Several understood that the reproductive failure of host would negatively affect the success of the
host.
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AM EXAMINERS’ REPORT MAY 2007
Question 2: Analysis of data
General Comments
o Statements such as “bats have to travel further distances to lactate their foraging bouts” indicate
that some students have a very poor command of basic English.
o It was appalling to see a number of candidates referring to bats as ‘birds’!
2.1. The majority of students were able to give adequate definitions to the phrase reproductively isolated
sympatric species. Some students mixed up sympatry with allopatry, however.
2.2. The answers to this question generally ranged from reasonable to very good. A common error was for
students to limit themselves to describing the foraging patterns with reference to Figure 1 only.
2.3 Some extraordinary answers were seen in response to this question such as “bats go out early to
exercise prior to labour!” Many failed to realize that energy demands would be highest during these
periods for development of foetus and for milk production. As a result more intensive foraging must take
place.
2.4 Few gave sensible answers to this seemingly straightforward question and a few bizarre answers such
as ‘bats communicate by means of UV rays’ were again seen . Few candidates realized that despite being
slightly intrusive, radio-tracking allows researchers to know the actual activity the bat is engaged in.
Being away from the roost does not necessarily mean foraging. The bats could be engaged in other
behaviour while away from the roost.
2.5 A surprising number of candidates assumed that P.pygmaeus would have higher infant mortality so
they would not need so much food. Such assumptions are unfounded and therefore could not be accepted.
Hardly any candidates realized that having larger roosts allows P. pygmaeus to thermoregulate more
efficiently and therefore fewer foraging bouts are required since less energy is expended.
2.6 Again, very few candidates arrived to the conclusion that P. pipistrellus is more of a generalist feeder,
therefore it need not travel too far away from the roosts, while P. pygmaeus is more of a specialist feeder
and needs to travel longer distances to locate its food.
2.7 This question was answered reasonably well by most candidates.
2.8 Most candidates missed the point that despite these two bat species being sympatric, their different
foraging behaviour indicates that they occupy two different ecological niches. Their behaviour must
therefore be clearly known in order to conserve both species adequately. Still several candidates were
awarded a mark if they suggested reasonable answers.
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AM EXAMINERS’ REPORT MAY 2007
Section B
Question 3: electron transport chains
One common failing was the lack of selectivity of information in this answer, which suggests that
candidates did not think carefully about what the question is actually asking, and wrote anything remotely
related to the topic. Most essays, in fact, consisted of lengthy and meticulously detailed accounts of
glycolysis and the Kreb’s cycle, followed by a short paragraph on the electron transport chain. Some
candidates limited themselves to describing the ETC in respiration only, consequently forfeiting marks.
Question 4: xylem and phloem
This was perhaps the most accessible of all the essays and candidates who attempted it scored rather well.
Question 5: countercurrent flows
Answers to this essay were rather variable. Scoring poorly in this essay was mostly due to the fact that
candidates limited themselves to describing countercurrent flow in one or two biological systems, most
commonly in the loop of Henle and as a means of thermoregulation in Arctic mammals, rather than due to
a lack of knowledge. This essay also revealed that most students do not give adequate importance to
diagram drawing when studying.
Question 6: arthropods
By far, this was the most difficulty essay, yet it was popular with quite a number of candidates. First of
all, most candidates attempting this essay ignored the instruction ‘Discuss’. This is by no means an easy
task and students should be encouraged to be critical of information they read. Most essays consisted of
sub-standard, almost rehearsed descriptions of the major features of the different arthropod classes. While
the main features of arthropods needed to be described, this essay, most definitely, had an evolutionary
slant. Candidates were expected to describe the environmental constraints that led to arthropodization and
the success of this group being dependent upon the development of a segmented body, the development
of an exoskeleton and jointed appendages. Statements such as ‘…being small they do not need a
complicated circulatory system’ or …‘the exoskeleton may have arisen due to the presence of a
haemocoel’ indicate that students are missing the point. It was clear, through some answers, that some
candidates find difficulty comprehending the concept of the coelom and haemocoel. Moreover, this essay
was littered with inaccuracies which were unacceptable at this level, such as, ‘arthropods have three types
of skin, or arthropod appendages are exposed to transpiration…’ An alarming number of students
included the cephalopods with the arthropods.
Section C
Question 7: General
Question 7.1: Most students restricted themselves to describing the different blood types in humans.
While securing a few marks by doing so, failing to state that a population with just one blood type would
be very susceptible and disastrously vulnerable to particular epidemics, lost them marks.
Question 7.2: The emphasis in this question is the evolutionary significance and yet again most
candidates limited themselves to describing the difference between actinomorphy and zygomorphy, with
some candidates giving an example of each type.
Question 7.3: Most students were able to give an adequate answer, to this question.
Question 7.4: This question was answered reasonably well by most candidates.
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AM EXAMINERS’ REPORT MAY 2007
Question 8: General
8.1 Although most candidates knew the meaning of the term endemic, very few gave proper scientific
answers to this question. Terms such as geographical isolation, reproductive isolation, adaptive radiation,
immigration, and the Founder Effect were expected here.
8.2 This question produced some most convoluted responses.
8.3 Again, most candidates rambled on about how we are destroying our world with little scientific
knowledge to support their answer. Some candidates did mention that the high carbon dioxide levels leads
to carbon fertilization which is typically a limiting factor for individual plant growth.
8.4 Most candidates could not muster more than one valid point, consequently forfeiting marks. Most
mentioned that higher temperatures would decrease precipitation but failed to mention other points such
as proliferation of diseases or higher risks of fire.
Paper 3
Question 1: TS of stem of maize
Generally speaking candidates did not perform well in this question often lacking detail or proper
representation of structures. Drawings often depicted what the candidate thought should be drawn rather
than what was present such as chloroplast sections, leaf sections, dicot stems, etc.
1.1 Candidates got the general principles of map drawings correct. However, scales or magnification and
titles were often missing. Candidates showed a general lack of understanding of biological drawings
sometimes drawing with a ball point pen and making other careless mistakes.
1.2 Most candidates drew a plan of the section. In addition, most labelling was incorrect. Scales and/or
magnification and titles were often missing. Candidates showed a general lack of understanding of
biological drawings.
Question 2: epidermal cells of onion
Generally candidates performed worst in question 2 often giving answers which lacked details or
describing unrelated methods (such as haemocytometer, change in length of potato strips, etc). Candidates
did not understand the questions presented.
2.1 Most candidates gave unnecessary detail such as fixing procedures etc. Others gave wrong details,
describing how the cells should be macerated with sand prior to staining. The majority identified the
correct stain and its effect.
2.2 Candidates generally knew that a form of ruler should be used, however the majority failed to mention
the eyepiece graticule or micrometer. Some mentioned the haemocytometer. On the other hand, some
methods mentioned such as measurement by area or by first measuring the length of the epidermis strip
and then counting the cells and dividing, were wrong. Few gave necessary details to merit full marks.
2.3 Candidates fared worst in this question. Most described change in length due to osmosis, even
mentioning the potato experiment and few gave necessary details to merit full marks. Although students
perform these experiments in the lab it seems that they fail to understand the significance and the
background.
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AM EXAMINERS’ REPORT MAY 2007
Question 3: Ecology
Generally candidates performed best in question 3. However, answers lacked details and clearly showed
that class based knowledge was not supplemented by field experience.
3.1
Most candidates answered by describing the line transect technique or quadrats. This shows a lack
of appreciation of what data is being asked. However, when the belt transect was indicated, the correct
method was described, although the wording left much to be desired.
3.2
In most cases, the reasons for choosing the particular test are not well-described. It seems that, in
some cases at least, the test was chosen randomly. In addition, candidates gave tests such as Simpson’s
Diversity, graphs, average etc.
3.3
The majority indicated the correct method. However, a proportion of candidates did not
understand the question and described a field method, rather than use of the photograph.
3.4
The majority of candidates gave the correct method. However, a proportion of candidates did not
appreciate that lizards are mobile animals and described the use of a line transect of quadrats.
Paper 4
Question 1: Taxonomy
The taxonomic groups of the specimens provided were correctly identified most of the time. However, in
1.2, though characteristics described were generally correct, sometimes these characteristics were not
diagnostic features of the phylum but of the class. Another problem was that sometimes, the diagnostic
features given were internal or otherwise not visible in the specimen provided, while the question stated
that characteristics listed should be clearly visible in the specimens. Also, a very common misconception
is that “insects are divided into three segments”, when in fact they consist of several segments fused into
three tagmata.
Question 2: Osmosis
The candidates were required to construct a table of their observations. Although generally complete,
sometimes the structure of the table was very disorganised, making it difficult to understand the
presentation of data. There were some inaccuracies in the understanding and definition of osmosis, in
particular, many candidates failed to specify that osmosis occurs across a semi-permeable membrane.
Also, candidates sometimes failed to realise that boiling would destroy the membrane and thus osmosis
would not occur.
Question 3: examination of biological material
There was a whole range of answers to this question. At one end were neat, accurate, well-annotated
biological drawings, with a title and scale, showing a good knowledge of fruit structure and development.
On the other hand, there were crude, untidy sketches with barely any labelling, or sometimes, incorrectly
labelled parts, without any title or scale. Moreover, it should be noted that when specimens are viewed
using the naked eye, scale must be given, and not magnification.
Chairperson
Board of Examiners
July 2007
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