transmission of the gene for albinism.

transmission of the gene for albinism.

 
SECTION A All questions in this section should be attempted. Answers should be given on the separate answer sheet provided.
1. Actin is a type of protein involved in A B C D contraction of muscles production of lactic acid protection against infection production of cell membranes. 5. The diagram below shows the transmission of the gene for albinism.

2. Which line in the table below describes correctly the bonds that create the shape of a protein at a particular stage of its formation? Shape of protein chain helix helix chain

Stage of formation A B C D primary structure secondary structure primary structure secondary structure

Bonds hydrogen hydrogen peptide peptide

KEY
Key unaffected male unaffected male unaffected female unaffected female

affected male affected male affected female
affected female

3. If ten percent of the bases in a molecule of DNA are adenine, what is the ratio of adenine to guanine in the same molecule? A 1:1 B 1:2 C 1:3 D 1:4

This condition is inherited as a characteristic which is A B C D dominant and not sex-linked recessive and not sex-linked dominant and sex-linked recessive and sex-linked.

4. The table below contains statements which may be True or False with regard to DNA replication and mRNA synthesis. Which line in the table is correct? DNA Replication True True True True mRNA synthesis False True False True

6. Two alleles of a gene code for different proteins. Both proteins are present in the heterozygote. This is an example of A co-dominance B sex-linkage C polygenic inheritance complete dominance. D

Statement A B C D Occurs in the nucleus Involved in protein synthesis Requires free nucleotides Involves specific base pairing

 

7. Which of the following are all examples of polygenic characteristics? A B C D Hand span, height and skin colour Blood group, height and foot size Hand span, tongue rolling and weight Blood group, foot size and skin colour

10. Changes in the ovary during the menstrual cycle are described below. 1 2 3 4 5 Corpus luteum forms Ovulation occurs Progesterone is produced Corpus luteum degenerates Graafian follicle develops

8. A substitution mutation results in a triplet of bases TTC being changed to TCC. The amino acid lysine is coded for by TTC and arginine by TCC. The effect of such a mutation on the resultant protein would be that A arginine replaces lysine throughout the protein B arginine replaces lysine at one position in the protein

The sequence in which these changes occur following menstruation is A B C D 2, 3, 1, 5, 4 2, 1, 3, 4, 5 5, 3, 2, 1, 4 5, 2, 1, 3, 4.

C lysine replaces arginine throughout the protein D lysine replaces arginine at one position in the protein.

11. Which of the following changes indicate ovulation is likely to have taken place? Body temperature rises falls rises falls

Cervical mucus A becomes sticky becomes sticky becomes watery becomes watery

9. The graph below shows changes in the concentration of hormones X and Y in the blood during the menstrual cycle. Concentration of hormone in blood

B C D

X

Y

?

12. Which of the following babies would be most likely to require a blood transfusion immediately after birth? A The first baby of a Rhesus negative mother and Rhesus positive father B The first baby of a Rhesus positive mother and Rhesus negative father

?

0

Time (days)

28

C

The second baby of a Rhesus negative mother and Rhesus positive father

Which of the following correctly identifies hormones X and Y? Hormone X A B C LH Oestrogen Oestrogen Hormone Y Oestrogen FSH Progesterone Oestrogen

D The second baby of a Rhesus positive mother and Rhesus negative father

D Progesterone

 

13. The diagram below shows the blood flow in the umbilical cord.

14. Nicotine is a chemical which may affect pre-natal development. The diagram shows the stages of development when major and minor malformations of organs may occur if there is exposure to nicotine. Key major malformation minor malformation Stage of development (weeks after fertilisation) Ball of Embryo cells (organ formation) 1 brain ear limbs genitalia For how many weeks during pregnancy is there a possibility of major malformations to organs during development? A 6 B 7 C 9 D 13 2 3 4 5 6 7 8 Fetus (organ growth and development) 9 10 11 12 13 14 15

umbilical cord X

embryo

Which line in the table below identifies correctly blood vessel X and the blood it carries?

Blood vessel X A B C D vein vein artery artery

Blood carried in X deoxygenated oxygenated deoxygenated oxygenated

15. Which of the following statements concerning the function of certain blood vessels is correct? A The vena cava carries oxygenated blood from the body to the right atrium.

B The pulmonary artery carries deoxygenated blood to the lungs from the right ventricle. C The pulmonary vein carries oxygenated blood from the lungs to the left ventricle.

D The aorta carries deoxygenated blood from the body to the left atrium.

 

16. Which line in the table below describes correctly the state of the heart valves during ventricular systole? Atrio-ventricular A B C D open closed open closed Semi-lunar open closed open closed

18. The graph below shows the effect of the carbon dioxide concentration of inhaled air on the breathing rate of an individual. 30 25 Breathing rate (breaths per min) 20 15 10 5 0 0 1 2 3 4 5 6 CO2 concentration (%) If the volume of one breath is 0·5 litre, what volume of air will be breathed in one minute when the CO2 concentration is 4%? A 6 litres B 9 litres C 18 litres D 36 litres

17. The diagrams below represent two different body designs.

Body design P

Body design Q 19. The table below shows the changes in brain volume that have occurred during human evolution. Time (million years ago) 3 2 1 0

Which of the following statements relating to these representations is correct? A B Body P has the same volume as body Q. Body P has a larger volume than body Q.

Brain volume (cm3) 500 600 800 1400

C Body P has a larger surface area than body Q. D Body P has a larger surface area to volume ratio than body Q.

By how much has brain volume increased during the last three million years? A 36% B 64% C 180% D 280%

 
20. Which sequence shows the correct order of the early stages of human infant motor development? A B C D Lifts head ? rolls over ? sits unsupported Sits unsupported ? lifts head ? rolls over Lifts head ? sits unsupported ? rolls over Rolls over ? sits unsupported ? lifts head

24. The following histogram shows the percentage distribution of IQ rating in a sample of 1000 Scottish children.
50

40

% of sample

30

21. Vision in dim light is improved by the rods connecting to A B C D diverging neural pathways converging neural pathways reflex neural pathways peripheral neural pathways.

20

10

0

22. The serial position effect shows that words in the middle of a list are usually poorly recalled because many of these words A have been displaced from short-term memory B have not been encoded into short-term memory

Less than 60

61– 80

81–100 101–120 121–140 IQ rating

More than 140

How many children have an IQ of over 100? A 38 B 53 C 380 D 530

C have been transferred into long-term memory D have been stored in long-term memory.

25. Four groups of students were asked to make paper aeroplanes. Each student had to make five aeroplanes. The table below shows the conditions under which each group worked. Written Demonstration set of on how to fold instructions the paper supplied Group 1 Group 2 Group 3 Group 4 no yes yes yes yes no no yes Prize for the first student finished no no yes yes

23. The following factors influence development of phenotype. 1 2 3 Environmental factors Genetic factors Maturation factors

In the study of monozygotic twins, which of these factors can be discounted? A B C D 1 only 2 only 1 and 2 only 1, 2 and 3

Which two groups are likely to be affected by social facilitation? A B C D [X009/12/02] Page seven Groups 1 and 4 Groups 2 and 3 Groups 2 and 4 Groups 3 and 4

[Turn over

26. The figures below show the population structure of a developed and a developing country. Male Female Developed country 70–74 65–69 60–64 55–59 50–54 45–?49 40–?44 35–39 30–34 25–29 20–24 15–19 10–14 5–9 0–?4 6 4 2 0 2 4 6 Percentage of population 70–74 65–69 60–64 55–59 50–54 45–?49 40–?44 35–39 30–34 25–29 20–24 15–19 10–14 5–9 0–?4 12 10 8 6 4 2 0 2 4 6 Percentage of population 8 10 12 Male Female Developing country

Age years

The percentage of the population under ten years of age in the developing country exceeds that of the developed country by A 12% B 14% C 24% D 32%.

27. The diagram below shows the relative movement of carbon within the carbon cycle. (Units are kg × 1012 carbon per year) Atmosphere

39

Age years

40

5

35

10

24

Animals 0·5 Oceans

Plants 0·5 Fossil fuels Organic Deposits

Plants 1·0

Animals Decomposers Land

Which component of the carbon cycle shows a net loss of carbon? A Atmosphere B Oceans C Land D Organic deposits Page eight

[X009/12/02]

28. The apparatus shown below was used to investigate the effect of concentration of phosphate on the growth of grass seedlings. Grass seedlings were grown in seven different culture solutions. The height of the grass seedlings was measured after 6 weeks.

29. The diagram below shows a simplified outline of the nitrogen cycle. Nitrogen gas A Nitrate D B Plant protein Animal protein

attached to air pump glass tube

grass seedling cork

C

Decay

Ammonia Which stage micro-organisms? does not involve

black paper cover

culture solution containing phosphate

30. Apple crop yields have been increased by plant breeders selecting for A disease resistance resistance to bruising sugar content.

Two variables that must be throughout this investigation are

the

same

B flavour C D

A volume of culture solution and concentration of phosphate in the culture solution B C concentration of phosphate in the culture solution and light intensity light intensity and temperature

D temperature and the height of the grass seedlings.

Candidates are reminded that the answer sheet MUST be returned INSIDE the front cover of this answer booklet.

 

1. Trypsin is an enzyme which catalyses the breakdown of proteins in the small
intestine. The graphs below show how pH and temperature affect the activity of trypsin. Graph 1—effect of pH on trypsin activity Activity (% of maximum) Activity (% of maximum) 4 5 6 7 pH 8 9 10 100 80 60 40 20 0 100 80 60 40 20 0 0 10 20 30 40 50 Temperature (°C) 60 Graph 2—effect of temperature on trypsin activity

(a) (i) State the optimum conditions for trypsin activity. pH temperature °C 1

(ii) State the range of conditions over which trypsin shows at least 40% of its maximum activity.

1 (iii) Explain the rapid decrease in activity shown in Graph 2.

 

(b) The pancreas produces and releases trypsinogen which does not breakdown proteins. In the lumen of the small intestine, trypsinogen is converted to trypsin by the enzyme enterokinase. trypsinogen enterokinase trypsin

(i) What term describes the effect of enterokinase in this reaction? 1 (ii) Explain why trypsinogen is produced in the pancreas instead of trypsin.
The diagram below shows the metabolism of three energy sources in a cell.

proteins

carbohydrates fats

intermediate compound

glycerol

X gas Z

pyruvic acid

acetyl CoA (a) Name X, Y and Z. X Y Z

Y

2

(b) What term describes the breakdown of carbohydrate into pyruvic acid during respiration? 1 (c) Describe what happens to acetyl CoA after it enters the Krebs Cycle.

1 (d) Under what circumstances would the body gain most of its energy from proteins? 1 (e) Carbohydrate is stored in the body as a polysaccharide. Name this polysaccharide and state where it is stored. Name Storage location 1

 

 

3. The diagram below shows the structure of one strain of the influenza virus.

 

Marks

nucleic acid

surface proteins

(a) This virus can be used to prepare a flu vaccine. In order to do this the nucleic acid must be broken up but the surface proteins left intact. Explain why it is necessary to: (i) break up the nucleic acid

(ii) leave the surface proteins intact (b) After a flu epidemic, two individuals, X and Y, were found to possess antibodies against this strain of influenza. X had recently recovered from flu while Y had been given a vaccine against it. Complete the following sentences by underlining one option from each pair shown in bold. The immunity gained by X is active/passive and naturally/artificially acquired. The immunity gained by Y is active/passive and naturally/artificially acquired. (c) A different vaccine is required against each strain of the influenza virus. Suggest why different vaccines are required. 2

2

1 (d) Researchers are attempting to develop a new vaccine which will be effective against all strains of the influenza virus. Trials of this new vaccine have shown that it increases the activity of T-lymphocytes in the body. Describe the method by which T-lymphocytes combat infection.
Haemophilia is a sex-linked disorder caused by a recessive allele (h) which results
in an individual producing a faulty blood-clotting protein. The diagram below shows the sex chromosomes from two individuals. position of gene for haemophilia

 
H

A

B

(a) Individual A is male while individual B is a female carrier of the allele for haemophilia. (i) Complete the diagram by labelling the alleles on the sex chromosomes of individual B. (ii) State the genotypes of individuals A and B. A B 1

1

(iii) What is the chance that a daughter produced by this couple will have haemophilia? Explain your answer. Space for calculation

Chance Explanation

%

1 (b) Karyotypes are images of fetal chromosomes arranged in homologous pairs. (i) State one feature of chromosomes which allows them to be paired in this way. 1 (ii) A mutation can occur during meiosis, in which chromosomes fail to separate. This results in an extra chromosome appearing in the karyotype. What term is used to describe the failure of chromosomes to separate during meiosis? 1
[X009/12/02] Page fourteen

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Marks

5. The flowchart summarises the processes involved in the production of semen.
Hormone X LH

Tissue Y

Testosterone

Structure Z substances secreted Semen

Sperm mother cells

Mature sperm cells

SEMINIFEROUS TUBULES

(a) Name hormone X and tissue Y. Hormone X Tissue Y 2

(b) Semen contains substances secreted by structure Z. (i) Identify structure Z. 1 (ii) Describe how a named substance from structure Z aids fertilisation. Substance Description 1 (c) Complete the table to show the percentage of each type of cell which would contain a Y chromosome. Cells Sperm mother cells Mature sperm cells 1 Percentage of cells containing a Y chromosome

[Turn over
[X009/12/02] Page fifteen

6. The graphs below show changes in the volume and composition of milk produced
by a woman in the first week following the birth of her child. Graph 1— changes in the volume of milk produced

800 Volume of milk produced (ml)

600

400

200

0 0 1 2 3 4 5 6 7 Days after birth Graph 2— changes in the concentration of lactose sugar and IgA antibody in milk Lactose IgA

Lactose concentration in milk (g/100 ml)

7

600

6

400

5

200

4 0 1 2 3 4 5 6 7 Days after birth
[X009/12/02] Page sixteen

0

IgA concentration in milk (mg/100 ml)

 

(a) (i) What name is given to milk produced in the first few days after birth? 1 (ii) From Graph 2, describe two ways in which the composition of milk produced in the first three days after birth differs from milk produced later. 1 2 (b) What was the volume of milk produced on day 3? (c) (i) Between days 2 and 3 this woman produced a constant mass of IgA. Explain why the concentration of IgA in her milk decreased during this time. 1 1

1 (ii) Express, as a simple whole number ratio, the concentration of IgA compared to the concentration of lactose produced on day 6. (1 g = 1000 mg) Space for calculation

 

: IgA Lactose (d) Using Graphs 1 and 2, calculate the mass of lactose produced on day 5. Space for calculation
The diagram below shows some blood vessels within muscle tissue of an athlete. The direction of blood flow is indicated by the arrows. X

P

Y

S venule (a) Name the type of blood vessels labelled X and Y. X Y (b) Name two substances which are at a higher concentration in the blood at point P than at point S. 1 2 (c) The athlete ran on a treadmill at high speed for ten minutes. Explain why the concentration of lactic acid in his blood increased during this time. 1 1

1 (d) Tissue fluid surrounds the muscle cells. Some of this fluid is reabsorbed into the bloodstream. How else is tissue fluid removed from around the muscle cells? 1
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Marks

8. The graph below shows changes in the volume of blood in the left ventricle of a
man’s heart. 140 120 100 Volume (cm3) 80 60 40 20 0
0 0·2 0·4 0·6 0·8 1·0

Time (s) (a) How long does ventricular systole last? (b) (i) What is the heart rate of this man? s 1

 

beats per minute (ii) Calculate the volume of blood leaving this man’s left ventricle every minute. Space for calculation

 

 

cm3 (c) When this man exercises, the volume of blood leaving his heart increases significantly. Describe how the nervous system and hormones cause this increase.

 
9. Infants and elderly people are especially vulnerable to hypothermia.

(a) (i) What is hypothermia?
(ii) State a biological reason why elderly people are particularly vulnerable to hypothermia.
(iii) Explain why an infant’s small body size makes him more vulnerable to hypothermia than a teenager.
(i) Name the body’s temperature monitoring centre. 1
(ii) Explain how the following cause a decrease in body temperature. 1 Increased sweating

2 Vasodilation 2

The diagram below shows a neurone from an adult. dendrites cell body presynaptic knob nucleus

myelin sheath

(a) Draw an arrow on the diagram to show the direction in which an impulse would travel. (b) Suggest a possible role of the nucleus in the transfer of information across a synapse.

1

1 (c) Complete the table below which contains information about organelles found in the presynaptic knob. Organelle Function Provides ATP for synthesis reactions Vesicle (d) (i) How might a neurone in a newly-born child differ from the one in the diagram? 1 (ii) In what way would this affect how the neurone functions? 1

 

11. Split brain patients cannot transfer information between their left and right
cerebral hemispheres because the band of nerve fibres connecting these areas of the brain has been cut. (a) Name the band of fibres which connects the two hemispheres.

Marks

1 (b) Some of the functions of each hemisphere are described in the table below. These functions are unaffected in split brain patients. Left cerebral hemisphere processes information from right eye controls language production Right cerebral hemisphere processes information from left eye controls movements of left hand

The diagram below shows an experiment on a split brain patient. The patient was asked to stare at a spot in the centre of a screen and the words “key” and “spoon” were flashed briefly onto the screen in the positions shown.

(i) The patient was then told to use his left hand to pick up the objects he saw named on the screen. Explain why the patient picked up the key but not the spoon.
(ii) The patient was then asked to say what he saw written on the screen. Predict what he would have said and give a reason for your answer. Prediction Reason 1
The following question relates to aspects of learning associated with guitar playing.

(a) What effect does practising a motor skill, such as repeatedly playing chords, have on the nervous system?

1 (b) Suggest how “shaping” might be used by a teacher to help students improve their guitar playing over the course of a year.

2 (c) (i) A teenager decides that she dislikes all of a band’s music after hearing just one song. What form of learning is this? 1 (ii) As she grows older this teenager’s opinion about the band’s music could be altered by internalisation. Explain how this may happen.
(d) Anti-social behaviour can occur when people are together in a group such as at a music festival. What is the name of this effect and why does it occur? Name Cause 1 1
The diagram shows land use within a valley in a developing country.

forest

village grassland river

(a) The population of the village near the river is increasing and the village is expanding. (i) State one way in which the land around the village would change if this expansion continued. Explain why this change would occur. Change Explanation 1 (ii) How might the resulting increase in the human population affect the river?
Some changes in land use increase methane release into the atmosphere. Give an example of such a change and state how methane release affects planet Earth. Example Effect (c) What name is given to the study of changes in the size of human populations? 1 1
An investigation was carried out to find out where pollution was entering a loch.
A student suspected that chemicals were entering the loch through one of the rivers that flowed into it (Figure 1). She collected a water sample from each of the three rivers that entered the loch. She then measured the concentration of nitrates and phosphates present in each sample. Her results are shown in the table below. Figure 1—map showing loch and rivers that enter it. Table—analysis of water samples Concentration of chemicals in water (mg/l) River loch scale 1 km C A B C Nitrate 2 35 5 Phosphate 0 10 1

B A

(a) Construct a bar graph to show the data in the table. (Additional graph paper, if required, can be found on Page thirty-four.)
(b) What conclusion can be drawn from the results of this investigation?

1 (c) State two variables which would have to be kept constant when collecting the water samples from each river. 1 2 (d) How could the student improve the reliability of her results? 1

1 (e) Suggest how the student could extend her investigation to allow her to locate more accurately the source of the polluting chemicals.

1 (f) The results of this investigation were obtained in the summer. Suggest why there would be a lower concentration of nitrates in all of the rivers if the investigation had been carried out in the winter.

1 (g) Describe the effects of excess nitrates entering a loch in summer.

 

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SECTION C Both questions in this section should be attempted. Note that each question contains a choice. Questions 1 and 2 should be attempted on the blank pages which follow. Supplementary sheets, if required, may be obtained from the Invigilator. Labelled diagrams may be used where appropriate.

Marks

1. Answer either A or B.
A Give an account of transport across the cell membrane under the following headings: (i) the structure of the membrane; (ii) osmotic effects on cells; (iii) endocytosis and exocytosis.

 

3 2 5 (10)

OR B  Give an account of the process of meiosis under the following headings: (i) first meiotic division; (ii) second meiotic division; (iii) significance of the process. 6 2 2 (10)

In question 2, ONE mark is available for coherence and ONE mark is available for relevance.

2. Answer either A or B.
A Describe processes that occur in the liver which bring about changes in the composition of the blood. OR B Describe processes that occur in the kidney which bring about changes in the composition of the blood. (10) (10)
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