Penrhos 2010 Trial WACE Answers.pdf

7/27/2019 Penrhos 2010 Trial WACE Answers.pdf

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Year 12 HBS Semester 2 Examination 2010

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21 (9 marks)

The table below shows the sequence of six amino acids in the protein haemoglobin, as it occurs in

humans and in each of four other primates (A,B,C and D),

PRIMATE AMINO ACID SEQUENCES IN HAEMOGLOBIN

Human proline serine alanine valine glycine - lysine

A lysine - alanine - threonine - valine - leucine - lysineB proline serine alanine valine leucine - lysine

C lysine - alanine - alanine - valine - leucine - lysine

D lysine serine alanine valine leucine - lysine

(a) Based on the above evidence, list the primates A,B,C and D from the primate which isMOST CLOSELY RELATED to humans (1) to the primate which is MOST DISTANTLYRELATED to humans (4).

MOST CLOSELY RELATED TO HUMANS 1. B___________________________

2. D___________________________

3. C___________________________

MOST DISTANTLY RELATED TO HUMANS 4. A___________________________(3 marks)

-1 for each one out of order

(b) Using an example, explain how the study of DNA in different species has added evidence forthe evolutionary process of speciation. (2 marks)


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Species that are closely related will have more similarities in their DNA; more distantlyrelated species will show greater differences. (1)For example, the genome of chimpanzees shows that they share over 98% of humanDNA. (1) [p263]

(c) The structure of the vertebrate forelimb provides evidence for an evolutionary relationshipbetween vertebrate groups. Describe this evidence. (2 marks)

The bones are all the same (1) i.e. one upper limb bone, two lower limb bones etc. (1) [p269]

(d) The vertebrate forelimb is one of a group of pieces of evidence for evolution collectivelyknown as homologous structures. Give two other examples of structures found invertebrates that illustrate homologous structures. (2 marks)

Muscle structures and arrangements Skeletal structures other than limbs Tail bone in primatestail and coccyx Alimentary canals Ear bones in mammals are homologous to gill and jaw bones in fish. [p.269-270]

22. [5 marks]

(a) What is DNA sequencing? [1]The determination of the precise order of nucleotides in a sample of DNA[p368]

(b) Give an example of the practical application of gene sequencing. [1]Comparing DNA sequences to look for changed alleles (mutations) [1]Maternity/paternity tests [1]

(c) Using modern biochemical techniques, it is possible to take genes from oneorganism and place them into the chromosomes of another.

(i) What is this process called? [1]Genetic engineering [1] or recombinant DNA technology [1] [p373](ii) Give one reason why you would want to do this. [1]

Replace faulty genes with healthy onesIdentify mutationsDetermine whether a person is carrying a particular gene or not[p373]

(iii) What is the name given to organism that possesses genes inserted fromanother organism? [1]

Transgenic organism(not plasmid or virus) [373]


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23. [6 marks]

The following table shows the name and function of a number of different kinds of pharmaceuticals.A specific example of each pharmaceutical is also listed. The details however, have been incorrectlyplaced in the table. In the blank table beneath, re-write the details so that each row correctly givesthe name, function and example for each type of pharamaceutical.

Type of Pharmaceutical Function Example

Analgesics Reducing levels of bad cholesterol Cortisol

Anti-inflammatories Pain relief Lipitor

Statins Reduction of redness and soreness

around an injury

Paracetamol

Type of Pharmaceutical Function Example

Analgesics Pain relief Paracetamol

Anti-inflammatories Reduction of redness and sorenessaround an injury

Cortisol

Statins Reduction of redness and soreness

around an injury

Lipitor


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26. [10 marks]

The diagram below shows some of the bones in the human skeleton.

(a) Name the following bones; [6 marks]

C femur_______________ G cranium (not skull)______________________

D patella________________ H mandible______________________

E tibia_____________ L phalanges______________________

G

H

I

J

A

B

C

D

E

F K

L


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26. [cont.]

(b) What is the appendicular skeleton? [1 mark]

The bones making up the upper & lower limbs + bones of the pectoral & pelvic girdles

(c) Give one function of the axial skeleton. [1 mark]

Provides support for erect posture [1]Protects CNS & internal organs [1]

(d) What is the function of the pectoral girdle? [1 mark]

Allows for the articulation of the arms to the axial skeleton

(e) On the diagram on the previous page, using red, colour in all the bones of thepectoral girdle. [1 mark]


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27. [cont.]

(f) Freely movable, (or synovial) joints are classified according to the type of movement

they permit. Three types are shown in the table below. For each, name the type ofjoint, give a specific place in the body where such a joint is found and describe therange of movement permitted by the joint . [9 marks]

JOINT NAME LOCATION TYPE OF MOVEMENT

PERMITTED

gliding

carpal bones in any direction in aside-to-side or back &

forth motion

hinge between humerus &

ulna(elbow = )

movement in one

plane only

saddle base of the thumb(I dont think I would

pay thumb)

both side-to-side andback & forth

(g) Several joints in the body actually do not permit any movement at all. What wouldbe the function of such a joint? [1 mark]

To provide strength

(h) Give an example of a joint that illustrates the function you gave in the previousquestion. [1 mark]

Suture joints in skull

Joint in between sacrum & pelvis

teeth


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28. [9 marks]

Examine the diagram below, which shows the embryonic development of a number of vertebrate

species.

(a) Briefly explain two ways in which this diagram provides supporting evidence forevolution. [4 marks]

Examples:

Embryos look very similar in the early stages [1] which suggests vertebrates are a closely

related group of animals [1]

Embryos all have gill slits present at some stage in their development. [1]Suggests vertebrates share an aquatic/fishy ancestor [1]

Tail is present in all embryos, even those of animals who dont have tails [1]suggests an evolutionary sequence that started with tailed organisms [1] or ancestors who

had a tail

(b) Vestigial organs present in humans are put forward as more anatomical evidence forevolution.

(i) What is a vestigial organ? [1 mark]

Structures of reduced size that appear to have no function

(ii) Give two examples of such vestigial organs. [2 marks]

Nictitating membrane/muscles to move ears/appendix/coccyxetc etc [see p.271]


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28. [cont.]

(c) What is it about the forelimb of vertebrates such as humans, bats, birds and whalesthat suggests that the species share a common ancestor? [2 marks]

The bones are all the same [1] arranged in a similar way [1]same number & type of bones [1] any 2 points. (should really only be worth 1 mark)

29. [11 marks]The graph below shows the decay curve for the radioactive isotope carbon-14.

(a) A piece of charcoal was retrieved from an ancient Homo sapiens camp site and

subjected to radiocarbon dating. The ratio of C-14 to C-12 was found to be0.125 in 1012. How old was the charcoal? [2 marks]

17,000 years +/- 500

(b) A stone tool was also recovered at the same site in the same layer of rock. Thisartefact could not be dated using radiocarbon dating. Why? [1 mark]

It is not organic in origin

(c) Another piece of charcoal found at the same site was also radiocarbon dated and

found to have a much larger C-14 to C-12 ratio. What does this tell us? [2 marks]

It is younger [1]Or less time has passed since the tree (or whatever) died [1]

Also the camp site has been used over a long period of time [1] any 2


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29. [cont.]

(d) Is radiocarbon dating an absolute or relative dating technique? Explain your answer.

[2 marks]

Absolute [1] because it gives an actual age in years [1]

(e) Where does C-14 come from? [2 marks]

From the atmosphere ()

Where cosmic rays () hit N-14 atoms ()And turn them into C-14 ()

(f) If C-14 is continually decaying to N-14, why does the amount of C-14 in a persons

body stay constant while they are alive?[1 mark]

Because the C-14 in our bodies is constantly being replaced by fresh C-14 [1]

Via food chains [1]

(g) Would fluorine analysis have been of any value in dating the two charcoal samples, if

carbon dating was not available? [1 mark]

Basically no, on the assumption that the charcoal is not burnt bone.(I would accept yes provided the argument was that the charcoal could have been

bone)

30. [14 marks]

(a) Which primate characteristic is illustrated in the diagram below? [1 mark]

Pentadactyl limb

A B C D


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30. [cont.]

(b) Which of the primates shown in the previous diagram would be best suited tobrachiation? Explain your answer. [3 marks]

B [1]Long fingers [1]Reduced thumb [1]

(c) Give a clear definition for the following terms. [6 marks]

(i) Opposability

Ability of the thumb to be drawn across the palm of the hand to touch tips of fingers [2]

(i) Diastema

Gaps in upper and lower jaws to accommodate large canines [2]

(i) Precision grip

Thumb-to-fingertip grip [2]. I would not pay holding a pencil etc as that is an example not adefinition

(d) There are several aspects to reproduction in which we see a clear evolutionary trend withinthe primates. Give two of these aspects and describe what the trend is. [4 marks]

Theres loads see p.311-312.1 mark for a clearly stated characteristic eg mobility of digits1 mark for the trend eg increasing mobility and ability to move digits independently of one another

Aspect 1:

Describe: ____________________________________________________________

____________________________________________________________________

Aspect 2: ____________________________

Describe: ____________________________________________________________

____________________________________________________________________


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31

(a) Describe and explain the difference between genetic drift and natural selection as processesthat result in evolution. Explain carefully how you might determine whether observations ofevolution were due to selection or to genetic drift. (12)

Natural Selection happens when changes occur due to different pressures on different populations whereasGenetic Drift may have no apparent cause.

Natural Selection: (any 5 from)The original population is separated (1) into two groups in different environments (1).

As there is no contact between them there is also no gene flow. (1)They have different selection pressures (1) e.g. one may be exposed to a particular disease that theother is not (1, any good example) causing differences in gene frequencies (1) between thepopulations.

Genetic Drift:Not caused by any selection pressure (1).

It results from random changes in gene frequencies (1) due to the mating behaviours or breedingrates of individuals (1)

Evolution due to NS or Drift? (2 x 2 marks for any clear explanation)Natural Selection will cause the entire population to gradually move to having a particularcharacteristic (1) e.g. all immune to that disease.Genetic drift could cause the characteristic of the population to increase or to decrease overgenerations (1)

Genetic Drift is more likely to occur in small populations (1) but Natural Selection can happen in anysized population. (1)

Natural Selection produces a population adapted to their environment (1) whereas Genetic Drift

changes are not related to the environment (1)

(b) Hospital patients who are in a coma experience a loss of function in many parts of theircerebrum and yet their heart continues to function normally. Give an explanation for howthe body is able to regulate heart activity in the absence of a fully functional cerebrum. (8)

The Heart rate and Stroke Volume is controlled by the Autonomic nervous system (1)Parasympathetic/Acetylcholine, stimulation will decrease heart activity (1)Sympathetic/noradrenalin stimulation will increase heart activity (1)They both act on the sinoatrial node or pacemaker (1) which is a group of cells capable of initiatingheart beats without external influence (1)

Any 3 from:

Changes to the symp/parasymp balance are achieved via;Blood pressure monitored by baro/presso-receptors in the Aortic/Carotid bodies (1) whichprovides feedback to receptors in the Cardiovascular Centre of the Medulla (1)Chemoreceptors in aorta and carotid arteries monitor carbon dioxide / pH of blood. (1)Oxygen levels monitored by chemoreceptors in aortic/carotid bodies.(1)


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(b) Apply your understanding of the primary immune response to explain the logic of thehygiene hypothesis (6).

Allergies are the result of antigens/non-self particles (1). In a sterile environment, there arerelatively few antigens (1). Sterile means germ-free (1)

So, in a sterile environment, there is little contact with antigens (1) and therefore they don'tproduce antibodies/cells (1) and most importantly, dont build up the memory cells. (1). So,later on in life, the secondary immune response doesnt occur (1)

(c) In 2003, the remains of partial skeletons of nine small, primate individuals, including onecomplete skull, were discovered on the island of Flores in Indonesia. Many scientists believethese remains to be a previously unknown extinct species of hominin, since named Homofloresiensis (and nicknamed "hobbits"). Other scientists refute the suggestion that this anhominin, pointing to similarities between the fossilised bones and those of apes, such aschimpanzees.

What sorts of evidence amongst the fossilised bones would suggest that hobbits werehuman and not ancient relatives of modern chimpanzees? (14)

See p320 they need to clearly explain 7 differences between pongids and hominins. Theres loadsto choose from.


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33(a) A skull is discovered embedded in a rock layer on a mountain side in eastern Tanzania.Describe four techniques that could be used to assign a date to the skull. For each technique quoted,also give a key advantage or disadvantage. (12)

TECHNIQUE DESCRIPTION (4 x 2 marks) ADVANTAGE/DISADVANTAGERadiocarbon dating Based on radioactive decay of C14 to

N14. Ratio of C14 to N14 is constantin all living things. Once dead, theratio changes. We are measuring theradioactivity of the remaining C14.

part that is dated gets destroyed/can give

an actual date in years/fossil must not beolder than 70,000 years

K-Ar Dating Based on the radioactive decay ofK40 to Ar40. The more Ar40, theolder the rock. Ar40 formed whenthe rock forms.

Requires soil that is volcanic inorigin/rocks must be older than 100 or200,000 years/very precise

Stratigraphy Uses the principal of superposition:layers on top are younger than thosebelow.

Only gives a relative date/distortions inthe earths crust occur/may have beenburied by an animal or someone else

Correlation of rock strata may bepossible to match the layer to a layerof known date elsewhere, by thefossils it contains. Index fossils

Only gives a relative date/requires thepresence of index fossils

Fluorine dating Fluoride ions leach into the bone astime passes. The older the fossil, themore fluorine it contains.

Only gives a relative date

(b) Describe the role of the various parts of the kidney tubule in the formation of urine. (12)

Glomerulus / Bowmans capsule [3]Blood is filtered (1)All substances small enough are filtered through walls of the Bowman's capsule (1)e.g. water molecules, glucose, sodium ions etc ARE (1)e.g. rbcs, plasma proteins ARE NOT (1)

Proximal convoluted tubule [4]

Allows selective reabsorption of materials (1)Moved by active transport (1)e.g. glucose, amino acids (1)Water follows (1) by osmosis (1)

Loop of Henle [1]allows selective reabsorption water by osmosis (1)plus sodium/minerals by active transport (1).

Distal convoluted tubule/collecting duct [4]Permit active reabsorption of water (1)Regulate water content of urine (1) via action of ADH (1)Permits secretion of substances into urine (1) e.g.

Thus, urine is composed of substances not reabsorbed (e.g. urea) (1)plus varying amounts of water (1)


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Penrhos 2010 Trial WACE Answers.pdf