School of Biological Sciences Bioscience Olympiad Answers, 2014
General Comments:
DO NOT USE WIKIPEDIA - in many answers there were direct copy/pasting from websites. Students are
allowed to look for material on websites. There were no restrictions in using any kind of sources, but at the
same time we do not do any negative marking.
Some files were not properly formatted. Please follow the question guidelines which detail the required font,
breaks, page numbers etc. correctly next year as there will be a penalty given.
About judging:
The level of answers we received this year was significantly higher that previous Olympiads. For example
never before the winning team got more than half of maximal score (opposite to 450 out of 700 for the 1st
prize now).
One mark was awarded for each point mentioned in the list of answers and each question was given a score
based on 100% of the total number of possibilities/explanations. For example if the total number of
explanations for question 3 was 13, team suggested 6 explanations got 6/0.13=46%. Final team scores are
simply the sum of all individual question scores i.e. a team can get a maximal total score out of 700%. The
brief list of possible answers in the pdf document is not necessarily a complete list of points and sometimes
additional points were given for a very original idea. Although we thought over all questions and had a list of
all the answers, usually a new good explanation per question appeared during judging. In this instance, it would
be given an additional point.
I noticed several examples of copy/pasting of information from the websites (mostly from Wikipedia-like
sites). This is fine as long as teams rephrase it and use for a purpose. For some questions it is necessary to sit
and think or do a simple brainstorming. It is not necessary to keep the references - we are looking for the
simple explanations of biological phenomena, not the peer-reviewed research paper or monograph. In addition,
it is not necessary to give a long description of facts, which are obviously easy to obtain since all teams have
access to the information. For example for Question 4 it was not necessary to explain the nature of all possible
pathogens found in tropics or to describe the epidemiological situation in Africa.
The most popular question was of course question 3. Most of the teams came with many ideas. The least
popular or elaborated was question 1. Very often students mixed up the cause and consequences especially in
evolutionary aspect (i.e. in questions 5 and 6). For question 1 all the mentioning of fruits did not get any points.
For the future, the model answers to the questions below are just brief points which we considered. We actually
expect more elaborated responses, usually with examples (even non-existent).
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School of Biological Sciences Bioscience Olympiad Answers, 2014
1. 1. Jack and Jill were arguing where the wax that the bees make comes from. Jill argued that bees
“harvest wax from flowers the same way as pollen”. Jack insisted that they “make it inside their
organism”. How to check who is right? Suggest as many experimental approaches as you can. (Read this
question carefully and answer the question).
First, we were considering answers to the question as exactly asked. We did not score parts which
started “As scientists have found..” “Bees have wax glands…”. We wanted you to answer the given question,
not just test your factual knowledge.
Answers like
“One experiment may be to observe bees while they harvest pollen from flowers. It could be observed
that bees do harvest wax from flowers in the same way they harvest pollen.”
“We can place cameras inside a hive to observe bees”
“We can look on what bees harvesting form the flower”
“Use mass spectrometry, (chromatography, IR-spectra, chemical analysis)”
– If given on it’s own, without further elaboration - scores zero. What would you look at? How do you
distinguish harvesting wax from harvesting pollen? What for would you use chromatography?
Some teams answered on what THEY are thinking how bees make wax. This did not answer the
question. Also, in this question we did not ask you how to make hive with glass walls and how to mount
miniature videocameras in there. The most important part was to design experiments and suggest PRACTICAL
ways to solve question what Jill and Jack were discussing.
A lot of very general suggestions like “observe bees behaviour inside the hive” “monitor what bee is
doing on a flower” etc. It was not clear, though what do you want to look at and how you would interpret your
observations.
The most common version was an experiment using two (or more) colonies of bees without or with
restriction in access to flower/nectar/pollen/wax. In many cases it was not stated what these bees in the
restricted colony will be eating. In any case, food is necessary to provide metabolic activity. Artificial
flowers/artificial food for bees/diluted honey would be a good approach to limit possible wax intake by bees
but leave food still there.
Several hypothesis on measuring various intake/excretion processes (by mass for example), although a
colony or even a single bee is not close system – they produce CO2, water, excrements etc. So it is not entirely
correct to weigh a bee before and after flower and after it leaves a hive.
Chemical analysis of the pollen and wax – was a very good approach. Wax is mostly fat and alcohols
while pollen is composed of sugars and protein. So technically speaking it would be not possible to make wax
from pollen by extraction, some biochemical conversion step should be included. It takes place in bees in
special glands.
Also, it is possible that there are two types of bees - “collectors” and “builders” – so when looking in the
hive you could actually monitor if there is any interaction or contact between these two types. Only two
schools considered this possibility.
So we consider three main approaches:
1. Monitor “builders”/”collectors” behaviour in the hive (very few)
2. Analyse chemical structure of wax/pollen or wax found in flowers/hive (50% of answers)
3. Analyse bee or flower in order to find wax-producing organs/glands. (80% answers)
All versions were scored the same, except the most common version of two/more colonies were scored
the least. Only two schools discussed to a certain degree all the version above.
Max=3
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School of Biological Sciences Bioscience Olympiad Answers, 2014
2 In the imaginary steppe of Varasta planet peculiar animals called Yzargs live. They are medium sized,
terrestrial scavengers. Xenozoologists described them as coward animals with long short body and short
paws. All travellers who went to Varasta noted that “Yzargs posess properties of swarming”. It means
that near every carrion suitable for eating Yzargs gather purposely very quickly in large quantities.
What do you think, how Yzargs can find out that carrion is available somewhere. Suggest as many
hypothesises as you can.
Obviously to answer this question you should have considered two parts: ability of a single Yzarg to
sense a carrion and than discuss the way of communication with others. At the same time they might all have
an ability to detect carrion in the vicinity. It was expected to discuss the ways of sensing AND ways of alerting
others
These two versions were discussed with different degrees of elaboration almost by everybody so,
depending on given details 0.15-0.25 points were given. Sensing the carrions included, sight, smell, follow
blood/chemical tracks, heat emission, electromagnetic fields or “unknown sense”. Good version was that they
climb on each other in order to get higher and see farther. However, it implies some sort of swarming BEFORE
detection of carrion.
Only one very original version was that Varasta is a planet with low gravity, so Yzargs, though having
short legs, could jump high to the air and simply spot the dead animal (very good Friends School Lisburn!).
Alerting others would include sound, light signals, smell, pheromones, direct telepathy, ground vibration,
radio waves, etc.
The question “how” they are gathering was not considered – by any means they could reach carrion either
by running or by teleportation.
Since the Yzargs are not tall they are not able to see far, so there were several hypotheses such as
symbiosis with other animals with an ability to spot carrion from far away (for example flying vultures) and
getting signals from them. Or maybe Yzargs just observe their behaviour in order to be able to get the location
of the carrion, follow predators when they are hunting or look at the flocks of flies gathering (0.2).
Avatar is a very popular film amongst the age group of the students so it was surprising that only couple
of teams suggested invisible telepathic web between all living creatures so that death of one individual is
instantly sensed by all others. Like they have on Pandora planet (0.2).
Of course it all can be a combination of versions.
A lot of explanations about types of communication similar to bees and ants, though there are no
indication that Yzargs do live in colonies. However, Yzargs can operate in colonies/herds/flocks – so that
scouts find carcass they alert their “fellows”. It will return us to “how find it” and how to alert the others”
issues anyway.
Max=0.7
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School of Biological Sciences Bioscience Olympiad Answers, 2014
3. It is known that many plants form compounds which are not used directly for nourishment,
respiration, growth or reproduction. What do you think, what functions these compounds could serve?
Support your answer with real examples.
This question was about purpose for plants, so those of you who did an explanation of purpose for people,
(not for the plant itself) got the question incorrectly. And a lot of talking about recreational drugs, which has
nothing to do with function of these compounds in plants either.
As many of you pointed out, this question was about so-called secondary metabolites. We did not ask
WHY plants may need them. Secondary metabolites are different form species to species so the question was
about different compounds serving various functions. Very few teams were concentrated on functions and give
examples, although the most of you concentrated on actual compounds giving a list of compounds with
explanation of function. Since you all had unlimited access to textbooks and internet discussing many different
molecules serving the same “defence function” was counted as one answer.
Some of you considered fundamental blocks of life: proteins, lipids and carbohydrates – they are essence
of life and they are fundamentally similar in all living creatures. No proteins = no life. Therefore examples of
“compounds” such as “proteins” “enzymes” (which are proteins), proteases (which are enzyme, phospholipids
(make cell membrane), were not counted. General things like acids, hydrogen ions, CO2, O2 etc – they are
inorganic metabolites or byproduct of any aerobic life including animals and they are present in all plants.
Chlorophyll and some other pigments – general photosynthesis so they were considered as nutrition and
were not counted.
Many answers like “flavonoids gives colour” or “Therpenoids give smell”, although no PURPOSE for
plants was discussed. Why it is good to be coloured or have smell – obviously it could attract animals, for
example pollinators.
So we counted the following:
1. Protection/defence: stinky, bitter, caustics, antifungal, antibacterial, phytoncides, hard shell, wax layers, etc.
They protect plants form eating/infection by other organisms. This was the most popular version, only 0.2
points were given (0.2).
2. Attraction (for example pollinators) – the second popular version. (0.3).
3. Sticky compounds to attached to the surface (ivy) – most obvious, but not so often suggested (0.3).
Strong versions:
4. Secretion – plants have no excretion system, so how would they get rid of wastes? CO2 or H2O can be
removed via stomata system but what to do with insoluble salts, toxic compounds and so on? So some plants
store in bark (leaves) and shed it at the end of the season. These for example are oxalates or phosphates. (0.5)
5. Strong version suggested by only two schools – antifreezes – special compounds preventing freezing or
decreasing the freezing point, so that no big ice crystals damaging for the cell are not formed. (0.6).
6. Hormones – also very common version. Signalling – it is very large group of compounds – it was not
necessary to get into all of them. It could include some antibacterial compounds too. (0.3).
7. Antioxidants- to scavenge free radicals and deal with UV-radiation damage (0.2).
8. Very obvious version – mechanical function such as lignin – to support stem or tree trunk (0.1).
9. Volatile organic compounds – suggested by very few teams and even less explained why they could be
needed – I liked the version on Rosemarie/Eucalyptus and forest fire. (0.4).
Max-1.4
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School of Biological Sciences Bioscience Olympiad Answers, 2014
3. In Dorothy and the Wizard in Oz by L.F Baum the following dialogue can be found:
«"How did they happen to be so little?" asked Dorothy. "I never saw such small pigs before."
"They are from the Island of Teenty-Weent," said the Wizard, "where everything is small because it's a
small island.»
In reality, does the size of animals dwelling an island depend on the size of the island itself? If it does not
depend, explain why. If it depends explain how. Please try to thoroughly justify your answer.
This question refers to so-called “Foster’s rule” or island rule. Big vertebrates isolated on an island tend to
become smaller, however small ones tend to become larger. It was however not necessary to discuss likelihood
of this rule “in general” but the question had to be structured in a way that you explain biological and
evolutionary reasons WHY small animals would become big on a big island or big animals become small in a
small. Or alternatively, WHY the size of an island does not make any effect. The answer such as “this is
because insular dwarfism” was not enough – you should have explained a mechanism of how size of the island
make decrease in size of animals.
For example: island size matters:
1. There are simply less number of animals on a big island, so there is higher chance for them to get
extinct. So with time, big ones disappear.
2. Less food (or whatever resources) so it is enough for small animals but not for big ones. So it would
result in gradual decrease in size. Big gregarious animals should go smaller since big herds/flocks
should evolve towards small size.
3. The possibility for the animal actually to get on the island is higher if it is small animal
4. Size of an island as mutagenic factor - discussible but unlikely, unless there is a nuclear power station
in there.
For example size does not matter:
1. There is a big animal on a small island, but as a species (or individual) it got to an island very recently,
so it is not really evolved yet, or it is about to die.
2. An island was big, but it is going smaller (like atoll island) so that big animals still there.
3. If it is not a single island, but archipelago with a large area in total.
Most of the teams considered only one possibility and took the answer about Foster rule from the interned
(with the same quotes and wording of phrases) and did not discuss the opposite. Banbridge Academy,
Bloomfield Collegiate considered both possibilities. Enniskillen Collegiate Grammar School provided very
good explanations and examples.
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School of Biological Sciences Bioscience Olympiad Answers, 2014
Also, many described things as effect of “climatic factors” – yes, climate is very important and it is different in
Madagascar and Iceland. However, when answering to this question you should consider two more or less
similar islands located at the same climatic zone and so on. They are different ONLY by size. So you should
have answered this question form that position.
Answers like “evolutionary changes in the small (big) island”, “it was a mutation” scored zero – it is clear, that
evolutionary pressure affects animal size and therefore size IS a product of evolutionary changes. But you
should have answered why and how it was directed towards bigger or smaller species.
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School of Biological Sciences Bioscience Olympiad Answers, 2014
5. In certain conditions (trauma or disease) an individual cannot obtain nutrition by mouth. This
problem is usually solved by inserting a feeding tube directly into the stomach or small intestine or
by administering intravenous injections of nutrients.
1. What kind of difficulties could arise with each of these methods?
2. Name relative advantages of each method.
There are various types of Feeding Tubes (FT) – one that goes into the mouth to the stomach (Nasogastric
Tube) and different types which surgically implanted via a small hole in the stomach wall (Gastrostomy Tube).
You should not have explained all of it. Alternatively there is parenteral feeding via IV. Students were
expected to focus on relative issues of both methods.
RT difficulties:
1. Artificial mincing of food pieces. They are not small/big enough for processing.
2. Absence of saliva treatment – it contains particular enzymes which activity can be important for
complete and effective digestion.
3. Irritation of inner walls of oesophagus – prone to infections.
4. Limitation in free movements.
5. Decrease in food variety – only semi liquid types can be given.
6. Possibility of chocking if something goes wrong.
7. Religious objections (it goes equally to IV, but IV suits to “medical treatment” which is might be
allowed, while RT is actual food consumption and can be strictly regulated in some religions).
Intravenous injections (IV):
1. Complete absence of digestion tract activity (peristaltics, microflora, moistening of the walls – not
good for the future.
2. Decreased immune defence since some factors are produced by bacterial cohabitants in various
segments of the tract.
3. Limitation in free movements.
4. Limited amount of nutrients. Should be carefully designed mixtures with vitamins and so on.
5. Disruption of epidermis =>possibility of infections.
6. Solutions with combinations of nutrients are not always available.
7. High osmolarity of the injected solution (not in all cases, though!!) may cause damage.
Advantages:
1.
2.
3.
4.
5.
6.
7.
8.
It is better to give unprocessed food in RT, than a mixture of nutrients IV.
In some cases IV can be combined with medicine.
IV is technically faster and requires less special training from a person administering it.
IV can be given to a person without any peristaltic activity due to the pathology or trauma (or after
long-time starvation) or unconscious.
IV can be used to decrease load to the intestines (during radioactive damage for example)
IV can be used in special cases such as prematurely born babies
Difference in costs of application.
For unknown patient possibility of food allergy reactions is less in IV.
Uncomfortability or feeling of hunger over IV can be considered, but in comparison with general condition of
such patients this might not be of a great concern.
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School of Biological Sciences Bioscience Olympiad Answers, 2014
Legal issues, alienation, dignity, self esteem and emotional distress reasons were not considered – we focused
only on biological effects.
List of various possible medical complications (blood clotting, thrombophlebitis, blood potassium drop,
embolism etc, scored as one reason. Also, there was no need to explain medical technicalities and details of all
gastroscopy and types of feeding tubes. Since you all have access to any source we understand you could do it.
More generalised and idea-based thinking were needed.
Since a lot of answers were taken from the web from clinical sites, there were several examples when
“advantage” for both methods were the same, i.e. “patient can live normal live”, “it saves lives”. You should
have used comparative approach – obviously both methods implies that they can “support life”, so it was not
necessary to discuss this part.
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School of Biological Sciences Bioscience Olympiad Answers, 2014
6. Suggest a classification of animal cells based on the shape of the cell in the organism. For each section
of your classification explain what role can these cells play in the animal body.
We thought it is the easiest and the most fruitful question to answer and easy to score. However, it turned out
to be a tricky one. Surprisingly, most of answers considered ONLY four or five categories without
subcategorising it further, so that sperm cell and neuron would be found in the same category. Some of you did
classification based not on the shape but on function or tissue type (i.e. epithelial, muscle, neuron, blood etc).
This was scored very-very low. Some of the classification combined shape and subcategories on function. It
was better, but still it was not what was asked.
Also classification does not imply creation of step by step dichotomous identification key, you goal was not to
identify unknown cell, but create a taxonomy/classification.
One of possible classification systems:
1. Long cells (lengths > 3×width)
a. One nucleus (smooth muscle)
b. Polynucleous (cross striation muscle)
2. Isodiametric (lengths < 3×width)
a. Spherical (eggs, adipocytes)
b. Polygonal base (epithelial),
i. Flat (capillary lining)
ii. Cubical (walls of renal tubules)
iii. Cylindrical (with/without cilia or microvilli) (epitheilial cells of trachea or bronchi)
iv. Scyphoid (glandular epithelial cells)
v. Amoeboid (leucocytes, fibroblasts)
c. Discoid (erythrocytes)
d. Collared flagellate cells (cellulae flammeae, choanocyte)
3. Branched cells (neurons, osteocytes, excretion glands in round worms)
a. Types of neurons – bipolar, unipolar, multipolar, etc.
b.
c.
4. Spirally twisted cells (Schwann's cell)
5. Special sophisticated design (rods – a lot of invaginations in the outer segment). This can be send to
category 1, though.
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School of Biological Sciences Bioscience Olympiad Answers, 2014
7. In the world-leading Institute of White-Yolk researcher Tim Davidson successfully isolated reversed
transcriptase enzyme from eukaryotic cells. This enzyme synthesises complementary DNA using an
iRNA template. How could you explain presence of this enzyme in eukaryotic cells?
Reverse transcriptase (RT) is an enzyme initially was found in viruses (retroviruses). These viruses
contain single strand RNA and one of its genes is encoding RT. When they enter the cell, from viral RNA
cellular ribosomes translate RT protein and then RT synthesize double stranded DNA and other cellular
enzymes (nucleases) insert this DNA into special sites in the cellular genome. This can have no consequences
if these sites are “silent”, genetic information will be transferred to offspring cells or even organisms. However
if inserted into special active site and in the special conditions (tissue types, hormones) viral DNA will be
copied into RNA and more RNA and RT molecules are formed. Virus is proliferating. Virus particles have to
be assembled (viral RNA + viral proteins +lipids) and released outside after or during cell death.
However, sometimes retrovirus loses its ability to proliferate normally and then leave the cell because of
the mutation of one or several genes encoding its shell proteins (capsid) or defects in self assembly. However,
other genes, including RT can be transcribed and then translated. This can be a reason why RT can be isolated
from many eukaryotic cells while no indication of viral infection is evident. It can be found even in complex
with proteins and RNA, so most likely it has some function in the cell, though we do not know what exactly.
You could have discussed possible functions of viral RT in a cell.
So, reverse transcriptase belongs not to the cell genome itself, but to the RNA of the virus, which infected
the cell.
The most important versions:
1. RT increase DNA copy number of a certain gene and then these copies are inserted to the genome – it can
result in
1.1 Cascade amplification of signal (it may be required for synthesis of many protein molecules – for
example proteins for secretion. In the genome we have very frequent sequences (10^5-10^6) per genome and
unique (10 copies per genome).
1.2. Copies can be inserted in various part of the genome (at the same place or in the different chromosome)
– and it would lead to increasing frequency of recombination or change in linkage groups. It is however rare,
since it would disrupt inheritance laws.
1.3 Exons and introns. If splicing took place already, RT could use short correct version of RNA to make
DNA from it and eventually increase the rate of protein biosynthesis. Splicing (cutting out intrones) takes a
long time since a lot of primary transcript got cut out. So making DNA from processed copies of RNA would
increase speed and save resources. This version is possible, but cannot be found in nature due to problems in
regulation and stability of such DNA/RNA
2. Versions discussing additional mechanisms for mutations. So that posttranscriptional changes in RNA are
not lost but can be reflected into genome via activity of RT.
3. Real eukaryotic RT = telomerase. Necessary for adding DNA repeats at the end of the chromosome. It
uses its own RNA primer for functioning. For the history of discovering telomerase go to
http://www.ncbi.nlm.nih.gov/pubmed/4754905
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2810624/
4. Retrotrasposones, but it would be necessary to discuss their function (see above)
3. Selection of more stable, longer lived RNA since more protein copies could be made from them.
4. Versions considering complex RT/DNA/RNA and possibility of its use for reparation processes.
5. Wrong interpretation and identification of the isolated product – it was not RT at all!
Examples of “hypotheses” scored zero if given on its own without further explanation:
The presence of RT leads to mutation of the genome
Because of evolutionary changes in time
It helps evolution of new genes
Increase RNA
It is used for insulin production
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School of Biological Sciences Bioscience Olympiad Answers, 2014
____________________________________________________________________________
The winners
1st prize - Banbridge Academy (475%)
2nd prize - Thornhill College, (443%)
3rd prize - St Patrick's Dungannon, (430%)
I hope you find the above useful. In comparison with the last years’ Bioscience, there has been significant
progress. More versions were suggested and more experimental approaches were discussed. Also, taking into
account that in the previous year only one school scored above 350% (half of the max total) and won the 1st
prize, this year there were nine schools which got over this threshold. Also the distribution of the scores was
relatively even, indicating that all schools suggested more or less obvious hypothesises. The mean value for all
the schools was 320%.
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