diagnostic evaluation september 2014

8/11/2019 Diagnostic Evaluation September 2014

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BSQ/IB Diploma Biology

Diagnostic Evaluation

This DIAGNOSTIC EVALUATIONat

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 18thSeptember.

Open up and get to work!

September 2014

John Osborne


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RUBRIC'COMPROMI SO 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 hadspanned 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.

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(b) Suggest two reasons for the very high mortality rate in the rabbit population when myxomatosis was

introduced in 1950.

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(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.

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(d) Suggest why there is still a 40% mortality rate to myxomatosis in present day rabbit populations.

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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.

(a) Give one other way in which living organisms may become fossilised.

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(b) Explain why the soft parts of the body are not fossilised.

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EVOLUTION- THE BIG IDEA

Iguanas are land-living reptiles. The adults feed on a variety of land plants whileyounger iguanas feed on

insects. They are found in many parts of the world, andshare features in common with each other. Charles

Darwin studied the iguanason 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 unusualto 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 totheir underwater feeding

sites. Darwin used these iguanas as examples of evolution occurring by natural selection.


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(a) What is meant by natural selection?

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(b) Explain how natural selection has given rise to different sorts of iguanas.

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(c) Evolution occurs by gradual changes from a common ancestor over long periods. How do these iguanas

provide evidence for evolution?

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(d) Give two reasons why people at the time when Darwin published On the Origin of Species did not accept the

idea of evolution.

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Lamark was a scientist working around the same time as Darwin, and he also developed a theory of evolution.

Lamarkbelieved that offspring inherit characteristics that their parents have acquired as a result of changes that

occur as they struggle to survive.

Darwinbelieved 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:

i) Lamarkstheory could be used to explain this increase in neck length?

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ii) Darwins theory could be used to explain this increase in neck length?

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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 7.

Obscure Immune Cells Thwart Ticksby Mitch Leslie on 26 July 2010

Resistance isnt 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 GraduateSchool 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 daysand banishes resistance to ticks, the scientists report in TheJournal 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 inthe body.

http://news.sciencemag.org/sciencenow/2010/07/obscure-immune-cells-thwart-tick.html
http://news.sciencemag.org/sciencenow/2010/07/obscure-immune-cells-thwart-tick.htmlhttp://news.sciencemag.org/sciencenow/2010/07/obscure-immune-cells-thwart-tick.htmlhttp://news.sciencemag.org/sciencenow/assets_c/2010/07/sn-ticks-thumb-autox600-3917.jpghttp://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 lymphocytesproduce 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 lymphocytesare 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 oflymphocytes.

Dendriti c Cell s

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.

Whi te Blood Cell s

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 arethe 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. Someimmunotherapy 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
http://www.chemocare.com/whatis/fullstory_iNewsid_128598.htmhttp://www.chemocare.com/whatis/the_immune_system.asphttp://www.chemocare.com/whatis/the_immune_system.asphttp://www.chemocare.com/whatis/the_immune_system.asphttp://www.chemocare.com/whatis/fullstory_iNewsid_128598.htm


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MAST CELLA granular cell found in body tissue, especially connectivetissue, that activates inflammation by releasing a variety ofchemical substances including heparin, histamine, serotonin,tumour necrosis factor, and interleukins. Mast cells havemembrane receptors that bind to bacteria, triggering the

release of inflammatory mediators from the mast cell'scytoplasmic granules. Mast cells also play an important rolein allergic reactions. Other receptors on their membranesbind to specific antibodies that, combined with certainantigens, initiate granular release of chemical mediators thatcause 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 QUESTIONabout 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. ANYaspect of what you have

read will do, but check with me first.)

b) Set about RESEARCHINGthe 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 waymaybe a directory or file which you can share with me through Google Docs, ora small file of notes.

c) PRESENTthe 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

EVALUATIONof 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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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 theirbeaks 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 insecttouches first.

[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]

(a) (i) State the relationship between the part of the beak that insects first touch and the

success rate.

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(ii) Suggest a reason for the relationship in (a) (i).

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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.

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Key:

Insect successfully

caught and swallowed

Insect lost

17%

83%

44%

56%65%

35%

Base of beak Middle of beak Tip of beak


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Very rapid wing beats keep a hummingbirds body steady near a flower while it collects nectar. Thisunusual type of flight behaviour is called hovering. Measurements were taken to investigate hovering infour hummingbird species. The body mass and maximum frequency of wing beats were measured. Thevelocity of the wing tips was measured when the wings were beating at their maximum frequency. Themean results are shown in the table below.

Hummingbird species

VariableBlue-throated(Lampornisclemenciae)

Magnificent(Eugenesfulgens)

Black-chinned(Archilochusalexandri)

Rufous(Selasphorus

rufus)

Body mass / g 8.40 7.40 3.00 3.30

Maximum frequency of wingbeats per second

30.70 31.90 59.70 62.20

Velocity of wing tips / m s1 16.80 16.50 15.80 16.90

[Source: Chai, 1997,Journal of Experimental Biology, 200, pages 27572763]

(c) State the relationship between body mass and maximum frequency of wing beats.

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The data in the table indicates that there is a similar maximum velocity for wing tip movement whateverthe overall size of the bird.

(d) Suggest oneproblem that would be caused by a velocity of wing tip movement greater thanthis.

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Hummingbirds are the smallest birds in the world, with adult masses ranging from approximately 2 g to20 g.

(e) Using the data in the table, suggest a reason why hummingbirds with a mass larger than 20 ghave not evolved.

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Hummingbirds maintain constant internal body temperature despite variation in external temperature. Theeffect of external temperature on Annas hummingbird (Calypte anna) was studied in a series of

experiments. At 40C 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 20C and 40C the volume of sucrose solution taken in per hour did not vary

significantly and was 0.70.8 cm3. At 10C the volume was significantly higher at 1.2 cm3per hour.

(f) Explain why the volume taken in per hour was higher at 10C than at the highertemperatures.

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Urine was collected from the hummingbirds at the three different external temperatures and wasanalysed to find the concentrations of nitrogenous waste products. The results are shown in the barchart below.

(g) Suggest onereason for the higher overall concentration of nitrogenous waste products in

urine at 40C.

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Concentration /

mol dm3

9

8

7

6

5

4

3

2

1

0

Key:

ammonia

urea

uric acid

10 20 40

Temperature / C


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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 10C is 4.4 :1.

(h) (i) Calculate the ratio between the concentration of ammonia and the concentration of

uric acid at 40C.

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(ii) Explain the difference in the relative amounts of ammonia and uric acid at 10C and at

40C.

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Hummingbirds use energy at a faster rate than any other bird or mammal.

(i) Explain tworeasons for the high rate of energy use in hummingbirds.

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(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.

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 cm3level.

2 Introduce some undiluted milk into the 1 cm3syringe, 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 cm3and 10 cm3marks 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.

The assignment tasks are below. These should be printed from the computer onto A4 paper,. This work must be

shared with me (Google Docs) so that it can be saved for your IB Practical Portfolio. Although you complete

this investigation with a partner, the assignment tasks must be your alone.

Data collection and processing

Record the time taken for three drops of each mixture to fall between the 100 cm3 and 10 cm3marks, and

calculate mean values. Record the results in the form of the most suitable table.

In what proportion must milk and water be mixed to have a density equivalent to the density of 0.1 M

copper(ii) sulphate solution? Explain how you arrived at your answer.

Plot all the results as a graph.

Conclusion and evaluation What can you conclude from this investigation? Explain how you justify your conclusion.

State the chief source(s) of error in this investigation and explain how it/they could be overcome.

Materials

100 cm3fresh milk

100 cm3distilled water

250 cm30.1 copper(ii) sulphate solution

two 10 cm3plastic syringes

1 cm3plastic syringe fitted with a long needle

two 100 cm3measuring cylinders

stop watch

diagnostic evaluation september 2014

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