BSQ/IB Diploma Biology
Diagnostic Evaluation
This DIAGNOSTIC EVALUATION at the start of the course is designed to assess the potential of the
new IB Biology students, and to find out how each individual in the group can be sufficiently
challenged, as well as what are particular targets, interests or aptitudes. This is achieved by setting
assignments in each of the assessment objectives, A, B, C, D & E. The diagnostic evaluation also
focuses upon the scientific process and will show how well you are able to handle enquiry based
learning.
Another most important factor of this Diagnostic Evaluation concerns your cooperation, management
of the time available and the way in which you direct yourself to the tasks and meeting the deadlines.
The rubric on Page 2 will be used to assess your personal commitment to this diagnostic evaluation.
There is 2 weeks work here – all to be completed and delivered by Thursday 18th September.
Open up and get to work!
September 2014
John Osborne
RUBRIC – 'COMPROMISO PERSONAL' in the Diagnostic Evaluation.
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QUESTION 1
(Objective B: Application of Knowledge and Problem Solving)
EVOLUTION
Myxomatosis is a virus disease in rabbits which is transmitted from rabbit to rabbit by rabbit fleas. The virus
causes blindness and then death. 12 rabbits were released in Australia in 1859. They reproduced rapidly and
started to spread quickly, so that by 1886 they were advancing at about 66 miles per year. By 1905 they had
spanned the continent. Rabbit proof fencing was inadequate to halt their progress.
In an attempt to control the huge rabbit population myxomatosis was introduced in 1950. It spread through the
rabbit population resulting in a 99.9% mortality rate. Over the next few years, however, the rabbit population
recovered although not to the pre-myxomatosis numbers. The mortality rate to myxomatosis in rabbits at present
is around 40%.
(a) Suggest two reasons for the rapid spread of rabbits across Australia between 1859 and 1905.
1. The rapid Spread of rabbits in Astralia was due to the rabbits being fast reproductive animals.
2. A ship came to Australia with rabbits. As soon as the ship came, the rabbits started reproducing.
(b) Suggest two reasons for the very high mortality rate in the rabbit population when myxomatosis was
introduced in 1950.
1. It was a very deadly disease.
2. Passed on through rabbit to rabbit by fleas.
(c) With reference to the genetic mechanisms involved; explain the recovery of the rabbit population from the
devastating effects of myxomatosis after its introduction in 1950.
Alleles are changed/ Genetic Resistance made them recover from the virus. Natural selection made some of
them survive and kept them reproducing.
(d) Suggest why there is still a 40% mortality rate to myxomatosis in present day rabbit populations.
Because natural selection still rules over the rabbits that can survive.
EVIDENCE FOR EVOLUTION
Only some parts of some animals and plants are fossilised. Usually, when animals and plants die their bodies are
covered by earth and they rot away. The organisms have to be in the right place at the right time to become
fossilised. Over time, the fossils are covered by earth, become compressed and change into rock. Three main
ways that fossils form are:
■ the body ends up in a place where decay is prevented, e.g.
frozen marshes, peat bogs, dry caves
■ parts of the plant or animal are replaced by other substances as
they decay, e.g. bones, teeth, xylem
■ hard parts of bodies decay very slowly, e.g. teeth, xylem, hair.
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(a) Give one other way in which living organisms may become fossilised.
Organisms get buried so years pass by and organisms don’t receive light. As years go by they decay and
become fossils.
(b) Explain why the soft parts of the body are not fossilised.
Because they get eaten by scavengers or dirt organisms. Another reason would be because they cant hold the
high pressures of the earth.
EVOLUTION- THE BIG IDEA
Iguanas are land-living reptiles. The adults feed on a variety of land plants while younger iguanas feed on
insects. They are found in many parts of the world, and share features in common with each other. Charles
Darwin studied the iguanas on the Galapagos islands and found that there were several different types of
iguanas. It appears that Ctenosaura, the black or spiny-tailed iguana of Central America, is ancestral to
Galapagos iguanas. The Galapagos iguanas feed on different types of food and showed differences in their
adaptations to obtaining food. Land iguanas feed on the fruit and pads of Opuntia cactus. It is not unusual to see
them sitting under a cactus, waiting for pieces to fall. They normally use their front feet to scrape the larger
thorns from the pads, but ignore the smaller thorns. Usually they gulp down a cactus fruit in a few swallows. On
some islands where their usual food was scarce, iguanas adapted to feeding on seaweed. The claws of the sea
iguanas are long and sharp by comparison with the land iguana, to enable them to cling to rocks along the shore,
and resist being pulled away by heavy waves. These claws also enable them to cling to their underwater feeding
sites. Darwin used these iguanas as examples of evolution occurring by natural selection.
(a) What is meant by natural selection?
Diversity is what natural selection works on.
Over time, those individuals who are most suited to their environment are more likely to survive and
reproduce.
(b) Explain how natural selection has given rise to different sorts of iguanas.
Since some harsh conditions kill iguanas, they are forced into changing. Natural selection forces them into
this process of changing. Different sorts of iguanas grow from this.
(c) Evolution occurs by gradual changes from a common ancestor over long periods. How do these iguanas
provide evidence for evolution?
Darwin explains the gradual changes of evolution by setting iguanas as an example. Iguanas show how they
are able to change depending on the conditions. Evolution is based on this changes that iguanas are able to
realize.
(d) Give two reasons why people at the time when Darwin published On the Origin of Species did not accept the
idea of evolution.
For cultural reasons of people regarding religion as their main belief they cant accept the theory of
evolution. People learnt most of their beliefs at church.
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Lamark was a scientist working around the same time as Darwin, and he also developed a theory of evolution.
Lamark believed that offspring inherit characteristics that their parents have acquired as a result of changes that
occur as they struggle to survive.
Darwin believed that differences between living organisms occur by chance, and those with the best
characteristics survive to breed, passing on their characteristics.
(e) Present-day giraffes have much longer necks than fossil forms of giraffes.
Describe how: Evolution
i) Lamark’s theory could be used to explain this increase in neck length?
Jean Baptiste Lamarck’s theory was that giraffes’ long necks were due to the giraffes over generations
that evolved reaching for higher leaves.
ii) Darwin’s theory could be used to explain this increase in neck length?
That as generations evolve they try to reach higher leaves each time so this parts from Darwin’s theory;
evolution.
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QUESTION 2
(Objective C: Research and Communication)
This all started when I read the article below. I found the article on the internet when trying to find out something about the
ticks which our dog picked up on the coast, during a holiday last year. Read the article below (from the BBC) and also the
support information following, about the immune system and mast cells. Do your best to understand it all and then make
the research which is outlined at the end, on Page 9.
Obscure Immune Cells Thwart Ticks
by Mitch Leslie on 26 July 2010
Resistance isn’t futile. Immune cells called basophils help prevent ticks from drinking their
fill of blood.
Credit: Thinkstock
Rare in the body and hard to study, immune cells called basophils have long gotten short shrift from researchers.
But a study now shows that basophils help repel bloodthirsty ticks that can spread lethal diseases. The work also
introduces a new method for teasing out further immune functions of the often-overlooked cells.
Many animals develop some resistance to ticks the first time the parasites feast on their blood. During later
feedings, fewer ticks latch on to resistant animals, and parasites that do attach sup less blood and sometimes
even die. Resistance provides another benefit, reducing the odds that ticks will transmit pathogens to their hosts.
Some evidence indicated that basophils play a role in tick resistance, but other research pointed to different cells
called mast cells. So identifying the key protector has been difficult.
In the new work, immunologist Hajime Karasuyama of the Tokyo Medical and Dental University Graduate
School in Japan and colleagues tracked basophils in mice troubled by ticks. When animals were first attacked by
the parasites, the cells rarely homed in on tick bites. But if the animals were on their second infestation, the
basophils, which normally circulate in the blood, swarmed to the bites and huddled around the parasites' mouth
parts. The team then experimented with two ways to temporarily remove the cells from a mouse's circulation.
First, the researchers used an established method, injecting mice with antibodies that glom onto basophils. Tick
resistance disappeared in these rodents. These antibodies, however, also eliminate mast cells, which made it
impossible to determine which cells were providing the benefit. To target basophils, the researchers devised a
new technique: they genetically engineered mice so that their basophils carried a receptor for the toxin produced
by the diphtheria bacterium. Giving such a mouse a dose of diphtheria toxin destroys the animal's basophils for
5 to 6 days—and banishes resistance to ticks, the scientists report in The Journal of Clinical Investigation .
"Now, we know that the basophil is quite important to acquired tick resistance," says Karasuyama.
Mast cells are also essential for tick resistance, the researchers showed. The team suggests that basophils are
necessary to trigger the response, whereas both kinds of cells help turn away ticks. Whether mast cells and
basophils collaborate or operate independently to foil the parasites is still a mystery. The tick work is part of a
surge of new research on basophils, some of it suggesting that they orchestrate immune responses to parasitic
worms and raise the alarm during bacterial infections. The lack of a method for selectively eliminating
basophils, leaving mast cells intact, had slowed studies of their functions. But immunologist Donald
MacGlashan of Johns Hopkins University School of Medicine in Baltimore, Maryland, says the genetically
modified mice created by Karasuyama's team are a "fabulous tool" to probe what else these elusive cells do in
the body.
http://news.sciencemag.org/sciencenow/2010/07/obscure-immune-cells-thwart-tick.html
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The Immune System:
Information about Lymphocytes, Dendritic Cells, Macrophages, and White Blood Cells
The Immune system is a complex network of cells (such as lymphocytes) and organs that work together to
defend the body against foreign substances (antigens) such as bacteria, a virus or tumour cell. When the body
discovers such a substance several kinds of cells go into action in what is called an immune response. Below is
a description of some of the cells that are part of the immune system.
Lymphocytes
Lymphocytes are one of the main types of immune cells. Lymphocytes are divided mainly into B and T cells.
B lymphocytes produce antibodies - proteins (gamma globulins) that recognize foreign substances (antigen) and
attach themselves to them. B lymphocytes (or B cells) are each programmed to make one specific
antibody. When a B cell comes across its triggering antigen it gives rise to many large cells known as plasma
cells. Each plasma cell is essentially a factory for producing antibody. An antibody matches an antigen much
like a key matches a lock. Whenever the antibody and antigen interlock, the antibody marks the antigen for
destruction. B lymphocytes are powerless to penetrate the cell so the job of attacking these target cells is left to
T lymphocytes.
T lymphocytes are cells that are programmed to recognize, respond to and remember antigens. T lymphocytes
(or T cells) contribute to the immune defences in two major ways. Some direct and regulate the immune
responses. When stimulated by the antigenic material presented by the macrophages, the T cells make
lymphokines that signal other cells. Other T lymphocytes are able to destroy targeted cells on direct contact.
Macrophages
Macrophages are the body's first line of defence and have many roles. A macrophage is the first cell to
recognize and engulf foreign substances (antigens). Macrophages break down these substances and present the
smaller proteins to the T lymphocytes. (T cells are programmed to recognize, respond to and remember
antigens). Macrophages also produce substances called cytokines that help to regulate the activity of
lymphocytes.
Dendritic Cells
Dendritic cells are known as the most efficient antigen-presenting cell type with the ability to interact with T
cells and initiate an immune response. Dendritic cells are receiving increasing scientific and clinical interest
due to their key role in the immune response and potential use with tumour vaccines.
White Blood Cells
There are different types of white blood cells that are part of the immune response. Neutrophils or granulocytes
are the most common immune cells in the body. With an infection, their number increases rapidly. They are
the major components of pus and are found around most common inflammations. Their job is to eat and destroy
foreign material. Basophils and eosinophils are white blood cells that contain large granules inside the
cell. They interact with certain foreign materials. Their increased activity may lead to an allergic reaction.
The immune response is a coordinated effort. All of the immune cells work together, so they need to
communicate with each other. They do this by secreting increased levels of a special protein molecule called
cytokines that act on other cells. There are many different cytokines. Examples of these are interleukins,
interferons, tumour necrosis factors, and colony-stimulating factors. Some immunotherapy treatment strategies
involve giving larger amounts of these proteins by an injection or infusion. This is done in the hope of
stimulating the cells of the immune system to act more effectively or to make the tumour cells more
recognizable to the immune system.
http://www.chemocare.com/whatis/the_immune_system.asp
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MAST CELL
A granular cell found in body tissue, especially connective
tissue, that activates inflammation by releasing a variety of
chemical substances including heparin, histamine, serotonin,
tumour necrosis factor, and interleukins. Mast cells have
membrane receptors that bind to bacteria, triggering the
release of inflammatory mediators from the mast cell's
cytoplasmic granules. Mast cells also play an important role
in allergic reactions. Other receptors on their membranes
bind to specific antibodies that, combined with certain
antigens, initiate granular release of chemical mediators that
cause allergic signs and symptoms.
THE ASSIGNMENT
These articles and information pages about immunity throw up so many ideas, unknowns and questions of
interest which demand further research. The knowledge which you and I presently have cannot handle all of this
and there are things which need following up. So here you go ......
a) Contrive a QUESTION about any aspect of what you have read above, a question that you would like
to answer. (You have great flexibility in deciding upon your question. ANY aspect of what you have
read will do, but check with me first.)
b) Set about RESEARCHING the answer to the question. The research could be from books or from
talking with experts, but is more likely to come from the internet. You research should be collected
together in some way – maybe a directory or file which you can share with me through Google Docs, or
a small file of notes.
c) PRESENT the research (your answer to the question) in whatever form you think is most appropriate.
Your audience will be the other Year 12 Biologists. This presentation could be a poster, a model, a
powerpoint, a research paper. I would like you to be as creative as possible. You will also have to
discuss your findings and answer questions.
d) Construct a short TEST or QUIZ which your audience will have to complete. This test/quiz will be the
EVALUATION of how well you have answered your question and communicated your new
knowledge.
An example of how this might be achieved:
a) QUESTION: How does a tick feed on the blood of a mammal?
b) RESEARCH: There are lots of lines of research, including tick mouth parts, anti-clotting
agents which ticks use, mammals which are the hosts for ticks, frequency of blood feeding, etc.
c) PRESENTATION: A labelled model of the head of a tick and its mouth parts, and an annotated
poster describing how the tick uses its mouth parts to penetrate the skin of a mammal and suck
blood.
d) TEST: A simple recall of the main ideas, including a labelled drawing.
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How to remove a tick



Use fine-tipped tweezers to grasp the tick as close to the skin's surface as possible.
Pull upward with steady, even pressure. ...
After removing the tick, thoroughly clean the bite area and your hands with rubbing alcohol, an iodine
scrub, or soap and water.
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1. Use fine-tipped tweezers to grasp the tick as close to the skin's surface as possible.
2. Pull upward with steady, even pressure. Don't twist or jerk the tick; this can cause the mouth-parts
to break off and remain in the skin. If this happens, remove the mouth-parts with tweezers. If you
are unable to remove the mouth easily with clean tweezers, leave it alone and let the skin heal.
3. After removing the tick, thoroughly clean the bite area and your hands with rubbing alcohol, an
iodine scrub, or soap and water.
4. Dispose of a live tick by submersing it in alcohol, placing it in a sealed bag/container, wrapping it
tightly in tape, or flushing it down the toilet. Never crush a tick with your fingers.
Avoid folklore remedies such as "painting" the tick with nail polish or petroleum jelly, or using heat to
make the tick detach from the skin. Your goal is to remove the tick as quickly as possible--not waiting
for it to detach.
* Another way to take a tick off is kind of dangerous. You can inject H2O2 to the tick and it will
explode. But this solution would be mortal even for yourself. This tactic would be good for the tick
after its taken off.
QUESTION 3
(Objective D: Evaluation of Data and Evidence and Making Conclusions)
Answer this data evaluation question.
HUMMING BIRDS
Hummingbirds have long narrow beaks that adapt them to collecting nectar from flowers. Nectar provides
energy in the form of sugar, but has very low concentrations of amino acids and protein. Therefore,
hummingbirds have to supplement their diet by catching flying insects. They do this by flying with their
beaks wide open towards insects. Scientists have used high-speed video to study the success rate for
catching insects. The pie charts below show the results, according to which part of the beak the insect
touches first.
Key:
17%
35%
44%
65%
Base of beak
56%
83%
Middle of beak
Insect successfully
caught and swallowed
Insect lost
Tip of beak
[Source: Reprinted with permission from Macmillan Publishers Ltd: Gregor M. Yanega and Margaret A. Rubega, “Feedingmechanisms:
Hummingbird jaw bends to aid insect capture”, Nature (2004), vol. 428, p. 615, © 2004]
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(a)
(i)
State the relationship between the part of the beak that insects first touch and the
success rate.
The nearer to the peak the bird has more chance on catching the insect.
(1)
(ii)
Suggest a reason for the relationship in (a) (i).
Its better to catch an object/insect with the wider part of the beak since there is less chance of
error.
(1)
Birds that feed only on flying insects have a different shape of beak from hummingbirds.
(b)
Predict, with a reason, the shape of beak in a species of bird that feeds only on flying insects.
Birds that feed only from flying insects have different shaped beaks because they need longer and
wider peaks to catch them.
(2)
Very rapid wing beats keep a hummingbird’s body steady near a flower while it collects nectar. This
unusual type of flight behaviour is called hovering. Measurements were taken to investigate hovering in
four hummingbird species. The body mass and maximum frequency of wing beats were measured. The
velocity of the wing tips was measured when the wings were beating at their maximum frequency. The
mean results are shown in the table below.
Hummingbird species
Blue-throated
(Lampornis
clemenciae)
Magnificent
(Eugenes
fulgens)
Black-chinned
(Archilochus
alexandri)
Rufous
(Selasphorus
rufus)
Body mass / g
8.40
7.40
3.00
3.30
Maximum frequency of wing
beats per second
30.70
31.90
59.70
62.20
Velocity of wing tips / m s–1
16.80
16.50
15.80
16.90
Variable
[Source: Chai, 1997, Journal of Experimental Biology, 200, pages 2757–2763]
(c)
State the relationship between body mass and maximum frequency of wing beats.
(1)
The data in the table indicates that there is a similar maximum velocity for wing tip movement whatever
the overall size of the bird.
(d)
Suggest one problem that would be caused by a velocity of wing tip movement greater than
this.
Hummingbirds would waste unneeded energy on moving their wing tips more. This would have
effects on their diet since they would have to eat larger portions to be able to move their
wing tips to an excessive velocity.
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(1)
Hummingbirds are the smallest birds in the world, with adult masses ranging from approximately 2 g to
20 g.
(e)
Using the data in the table, suggest a reason why hummingbirds with a mass larger than 20 g
have not evolved.
(1)
Its not possible for the birds to weight more than 20g because their wings and body overall cannot
sustain a body mass heavier than 20g. Their max frequency of wing movement per second would
be so low that it would be impossible for them to fly and to catch insects.
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Hummingbirds maintain constant internal body temperature despite variation in external temperature. The
effect of external temperature on Anna’s hummingbird (Calypte anna) was studied in a series of
experiments. At 40C the hummingbirds were observed to rest after short flights and ventilate their lungs
rapidly to cool their bodies by evaporation of water (panting).
The hummingbirds were placed in different external temperatures and a dilute solution of sucrose was
given to them. Between 20C and 40C the volume of sucrose solution taken in per hour did not vary
significantly and was 0.7–0.8 cm3. At 10C the volume was significantly higher at 1.2 cm3 per hour.
(f)
Explain why the volume taken in per hour was higher at 10C than at the higher
temperatures.
The bird creates a movement on his wings to keep his body warm.
(2)
Urine was collected from the hummingbirds at the three different external temperatures and was
analysed to find the concentrations of nitrogenous waste products. The results are shown in the bar
chart below.
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Key:
8
ammonia
urea
uric acid
7
6
Concentration /
mol dm –3
5
4
3
2
1
0
10
20
40
Temperature / °C
(g)
Suggest one reason for the higher overall concentration of nitrogenous waste products in
urine at 40C.
(1)
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The high overall concentration of nitrogenous waste products in urine is because it heats the bird up.
The ratio between the concentration of ammonia and the concentration of uric acid in the urine of
hummingbirds changes as the temperature rises. The ratio at 10C is 4.4 :1.
(h)
(i)
Calculate the ratio between the concentration of ammonia and the concentration of
uric acid at 40C.
7.9: 4.8
(1)
(ii)
Explain the difference in the relative amounts of ammonia and uric acid at 10C and at
40C.
Ammonia is on a 2.1 when being at 10 Celsius. By seeing this its visible that when its on 40
Celsius the ammonia amount would be at 7.9.
(2)
Hummingbirds use energy at a faster rate than any other bird or mammal.
(i)
Explain two reasons for the high rate of energy use in hummingbirds.
1.
They use a lot of energy because they move their wings so much
2. By inhering so much sugar from the pollen they give out a lot of energy.
they (2)
(Total 15 marks)
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QUESTION 4
(Objective E: Experimental Investigation. Group work)
Complete this investigation with a partner and answer the assignment questions below.
A METHOD FOR MEASURING THE DENSITY OF MILK: COPPER PROTEINATE FORMATION
A method is described below for determining the relative density of protein-containing fluids, such as milk or
blood. Measurements are made to determine the rate at which drops of milk, or milk-water mixtures, fall under
gravity through a copper(ii) sulphate solution. A layer of copper proteinate forms around each drop, preventing
dispersal of the milk.
Materials
 100 cm3 fresh milk
 100 cm3 distilled water
 250 cm3 0.1 copper(ii) sulphate solution
 two 10 cm3 plastic syringes
 1 cm3 plastic syringe fitted with a long needle
 two 100 cm3 measuring cylinders
 stop watch
Method
1
Pour the solution of copper(ii) sulphate into the two measuring cylinders, filling each one to a depth
approximately 5 cm3 above the 100 cm3 level.
2
Introduce some undiluted milk into the 1 cm3 syringe, fitted with the long needle.
3
Place the tip of the needle just below the surface of the copper(ii) sulphate solution.
4
Gently press the plunger of the syringe to release a small drop of milk.
5
Record the time taken for the drop to fall between the 100 cm3 and 10 cm3 marks of the measuring
cylinder.
6
Repeat this procedure using the second measuring cylinder.
7
Obtain the times taken for 3 drops to fall and calculate a mean value. (Data collection and processing)
8
Make dilutions of the milk containing, respectively, 5, 10, 20, 30, 40, 50 and 60% milk by volume.
Repeat the procedure above with each milk-water sample.
Conclusion and evaluation
 What can you conclude from this investigation? Explain how you justify your conclusion.
1. 18 sec
2. 19 sec
3. 20 sec
4. 14 sec
5. 15 sec
6. 13 sec
Average: 26.6
I can conclude that currently we are incompetent to fulfil an experiment. Mainly human error is what caused
this investigation to fail to produce valuable results in order to figure out the density of milk.
Evaluation: the margin of error in the investigation was very big since no good results were obtained. We could
have had better preparation to fulfil the task.
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