AS BIOLOGY OCR A | Every Food and Health Question

8/18/2019 AS BIOLOGY OCR A | Every Food and Health Question

1/92

1. A balanced diet is essential for good health.

Complete the following passage by using the most appropriate terms from the list to fillthe gaps.

Each term should not be used more than once.

haemoglobin iron collagen obese

calcium anorexic sodium

A balanced diet is one which provides an adequate intake of energy and nutrients for

the maintenance of our body. If energy intake exceeds energy usage over a period of

time, an individual can become . .

!he deficiency disease anaemia can be caused by a lack of the mineral

. in the diet. As a result of this deficiency, the body is unable to

produce sufficient amounts of the protein . in red blood cells.

"!otal # marks$

2. !he %ody &ass Index '%&I( is one way of determining whether a person isunderweight or overweight.

%&I can be calculated using the formula)

*m(in'height

kginmass%&I =

Calculate the %&I of a female of mass + kg and a height of -.+ m.

/how your working. 0ive your answer to one decimal place.

Answer 1 ..........................................

"!otal * marks$

Macmillan Academy 1


2/92

3. A way of determining whether a person is underweight or overweight is to use a graphshowing the relationship between height and body mass.

!he figure below is an example of this type of graph.

- . 2 3

- . + 3

- . 3

- . 4 3

- . 3

h e i g h t ' m (

5 3 2 3 + 3 3 4 3 3 - 3 3 - - 3 - * 3 - # 3 - 5 3 - 2 3

m a s s ' k g (

a c c e p t a b l eu n d e r w e i g h t o v e r 6w e i g h t

o b e s e

m o r b i d l yo b e s e

'i( 7sing the figure above, state the category into which a female who has a bodymass of + kg and a height of -.+ m is placed.

.........................................................................................................................

"-$

Macmillan Academy 2


3/92

'ii( !here are many factors that determine the category into which a person isplaced. !he figure above does not take into account all of these factors.

/uggest why the female in 'i( might be placed in the wrong category.

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

"*$

"!otal # marks$

4. 8ame two diseases associated with obesity.

- ...............................................................................................................................

* ...............................................................................................................................

"!otal * marks$

Macmillan Academy 3


4/92

5. Coronary heart disease 'C9:( can be described as a multifactorial disease. !hismeans that a number of different risk factors contribute to the development of thedisease.

!he figure below shows the percentage of cases of C9: in a population to which eachrisk factor contributed.

C H D due to lack ofexercise (37 % )

all C H D

C H D due to highblood pressu re(13% )

C H D due to highblood ch olesterol(4 6% )

C H D d u e tosm oking (19% )

'i( ;hen you add up the different risk factor percentages for the population you findthat it is greater than -33


5/92

'iii( /moking is a contributing factor in -< of all cases of C9:.

!he table below lists a number of effects of cigarette smoke.

7se a tick ' ( to indicate which component of cigarette smoke causes each

effect.

!he first row has been done for you.

effect nicotine carbonmonoxide

increases heart rate

constricts arterioles

damages the lining of arteries

reduces the ability of haemoglobin to carry oxygen

makes platelets sticky

"5$

"!otal marks$

6. Cholesterol is transported in the form of lipoproteins. 9igh levels of low densitylipoproteins '=:=s( in the blood are a risk factor in heart disease.

>utline the role of =:=s in the formation of an atheroma.

..................................................................................................................................

..................................................................................................................................

..................................................................................................................................

..................................................................................................................................

..................................................................................................................................

..................................................................................................................................

"!otal * marks$

Macmillan Academy 5


6/92

7. An atheroma can grow to a point where it restricts blood flow in a coronary artery,causing coronary heart disease 'C9:(.

!he figure below shows a method of reducing the symptoms of C9:.

A stent is a tubular device, containing a ?balloon@, which can be inserted into thedamaged artery. !he stent can be opened up by inflating the balloon.

a r t e r ya t h e r o m a

s t e n t

b a l l o o n

t h e b a l l o o n i s

g e n t l y i n f l a t e d

a n d t h e s t e n t

e x p a n d s

t h e b a l l o o n i st h e n l e t d o w n a n d

r e m o v e d , l e a v i n gt h e s t e n t i n p o s i t i o n

Explain how the inserted stent would reduce the symptoms of C9:.

..................................................................................................................................

..................................................................................................................................

..................................................................................................................................

..................................................................................................................................

..................................................................................................................................

..................................................................................................................................

..................................................................................................................................

..................................................................................................................................

"!otal 5 marks$

8. &alaria kills over one million people every year, the vast maority being under the age

Macmillan Academy 6


7/92

of ten.

Adults who have survived malaria in childhood and then continue to live in an areawhere malaria is found, develop a limited form of immunity.

'a( 'i( 8ame the parasite that causes malaria.

................................................................................................................

"-$

'ii( 8ame the vector for the malarial parasite.

................................................................................................................

"-$

'iii( 8ame a human cell in which the malarial parasite reproduces.

................................................................................................................

"-$

Macmillan Academy 7


8/92

'b( /cientists are developing a vaccine using an attenuated 'inactive( form of themalarial parasite.

!he aim is to trigger an immune response without the development of the

disease.

:escribe the actions of the B lymphocytes in the immune response.

In your answer you should make clear how the steps in this part of the immuneresponse are sequenced

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

"4$

'c( /uggest why adults who have survived malaria may lose their immunity when

they leave a malarial area.

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

........................................................................................................................."*$

Macmillan Academy !


9/92

'd( /tate three biological reasons why it has not been possible to produce aneffective vaccine for malaria.

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

"#$

"!otal -+ marks$

9. !he figure below shows a diagram of alveoli in a healthy lung and alveoli in a lung froma person with advanced emphysema.

i n t e r i o r o f a l v e o l i

alveoli in a healthy lung alveoli from a person with advanced emphysema

Macmillan Academy "


10/92

'i( :escribe how smoking could cause changes in alveoli, such as those shown inthe figure above.

In your answer you should make the links #etween the chan$es and their causesclear

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

"+$

'ii( Emphysema is a form of chronic obstructive pulmonary disease 'C>B:(.

:escribe two signs or symptoms of emphysema.

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

"*$

Macmillan Academy 1%


11/92

'iii( Emphysema is described as a chronic disease.

/uggest the meaning of the term chronic .

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

"*$

"!otal -3 marks$

10. An investigation was conducted into the effect of smoking on lung function. >nemeasure of lung function is peak flow rate.

!he peak flow rate is the maximum volume of air expelled from the lungs in one minute

'dm# min

-(.

!wo male volunteers, one a smoker and one a non6smoker, had their peak flowmeasured once a year for seven years.

- # - 5 - 2 - + - - 4 -

* 2 3

* 2

# 3 3

# * 2

# 2 3

# 2

s m o k e r

D e y )

n o n s m o k e r

a g e ' y e a r s (

p e a k f l o w r a t e

' d m#

m i n -

(

Macmillan Academy 11


12/92

'i( Describe the data shown in the figure above.

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

"5$

'ii( Explain the results obtained for the smoker.

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

"*$



13/92

'iii( /uggest three ways of improving the reliability of this investigation.

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

"#$

"!otal marks$

11. Acacia sene$al is a species of tree which is common in the drier parts of Africa. Cattleare allowed to grae on both its leaves and the fallen seed pods. !he seed pods haverelatively high protein content.

'i( :escribe how you would test an extract of the seed pods for protein.

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

"*$



14/92

'ii( :escribe how you could compare the reducing sugar content of the leaves withthat of the seed pods.

In your answer you should make clear how the steps in the process aresequenced

"4$

'iii( !he seeds of Acacia species are sometimes eaten by people.

/uggest why it might be better for people living in areas where the tree grows tolet their cattle feed on the trees and fallen seed pods and then obtain theirnutrition from the cattle.

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

"#$

"!otal -# marks$



15/92

12. An antibody is an example of a protein molecule, which has a specific #6dimensionalshape.

!he diagram below shows the structure of an antibody molecule.

h e a v y p o l y p e p t i d ec h a i n s

l i g h t p o l y p e p t i d ec h a i n

c o n s t a n t r e g i o n v a r i a b l e r e g i o n

'i( >utline how the structure of an antibody molecule is related to its function.

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

"#$



16/92

'ii( /uggest why the base sequence in the genes for human antibodies is moresimilar to that found in a chimp than to that found in a mouse.

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

"*$

"!otal 2 marks$



17/92

1. !he 9uman Immunodeficiency Firus '9IF( is spread by exchange of body fluidsbetween an infected person and an uninfected person. !his often occurs as a result ofunprotected sexual intercourse.

!he diagram below shows the percentage of people infected with 9IF in different partsof the world at the end of *33*.

; e s t e r n E u r o p e

33 .. 22 --


18/92

'ii( Explain why it is useful to collect information, such as that shown in the figureabove.

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

"5$

"!otal marks$

1!. At present there is no cure for 9IF AI:/. Jesearchers have found that some peoplein Africa are not infected despite continual exposure to the disease. 9IF uses a specific

cell surface receptor known as the C:5 receptor to enter a human cell.

/uggest how this information and knowledge of the 9uman 0enome might be used tohelp reduce the spread of 9IF.

..................................................................................................................................

..................................................................................................................................

..................................................................................................................................

..................................................................................................................................

..................................................................................................................................

..................................................................................................................................

"!otal * marks$

Macmillan Academy 1!


19/92

1". >ver the last few years there has been much public concern over the diet of people inthe 7D and its effects upon their weight and health.

%ody &ass Index is a calculation used by doctors to indicate whether a person is

underweight or overweight.

'a( /tate the medical term used to describe a person whose %ody &ass Index isgreater than #3.

.........................................................................................................................

"-$

!he table below shows the daily intake of certain components in three diets,#, B and $ for men in the 7D.

:iet # K a normal balanced diet for a typical man

:iet B K a weight6reducing low fat dietK restricted to avoid fatsK includes any fruit, vegetables and proteinsK energy intake is monitored carefully

:iet $ K a weight6reducing low carbohydrate dietK restricted to avoid carbohydratesK excludes fruit as these contain sugars

K includes any non6starchy vegetables, proteins and fatsK energy intake is not counted and may exceed -3 333 kLon some days

:iet #normal balanced

diet

:iet Bweight6reducing

low fat diet

:iet $weight6reducing

low carbohydratediet

energy kL *3 +333 4333

fats g 4 #5 -*5

carbohydrates g *2 *33 *3

proteins g 44 + -+2

combinedminerals g

-* -* -4

Macmillan Academy 1"


20/92

'b( In any unbalanced diet it is possible that there may be a deficiency of certainnutrients.

/uggest one nutrient that may be deficient in diet B and one in diet $.

:iet B ..............................................................................................................

:iet $ ..............................................................................................................

"*$

'c( 'i( Explain which diet, B or $, is likely to cause more rapid weight loss.

................................................................................................................

................................................................................................................

................................................................................................................

................................................................................................................

"*$

'ii( /tate the relationship between energy intake and energy use that wouldallow a person to lose weight.

................................................................................................................

"-$



21/92

'd( :octors suggested that diet $ may not be very healthy in the long term, as itcontains unlimited amounts of fats and no fruit.

/uggest what potential health problems, other than continued weight loss,

might result in a person who kept to a low carbohydrate diet, similar to diet $.

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

"#$

"!otal marks$

1%. Jead the following passage and complete each sentence by writing the mostappropriate word in the spaces provided.

9ealth can be defined as a state of complete ....................................., mental and social

well6being. It is not merely the absence of infirmity or ..................................... . &any people

may consider themselves healthy, even though they do not fully match the above criteria. A

young woman can improve her health in a number of ways.

!o improve physical well6being she should eat a balanced diet in which the maority of her

energy needs come from ...................................... 9er diet should include only small

quantities of ..................................... fats and more plant oils, such as olive oil. /he should

exercise for at least ..................................... minutes on three or more occasions per week.

!his exercise should be at an intensity that raises her heart rate to .....................................

percent of her maximum heart rate. /he should not smoke at all and should avoid passive

smoking.

"!otal + marks$



22/92

1&. !he diagram below shows the incidence of coronary events and mortality fromcoronary heart disease 'C9:( in some countries around the world. !he incidence ofcoronary events refers to the number of reported cases of any form of coronary illnessper -33 333 of the population.

!he diagram also shows the prevalence of smoking in the same countries. !heprevalence of smoking is the percentage who smoke cigarettes every day.

!he figures in the diagram refer to men aged from #2 to +5 during the late -3s.

A u s t r a l i a3

- 3 3

* 3 3

# 3 3

5 3 3

2 3 3

+ 3 3

3 3

4 3 3

i n c i d e n c e

o f c o r o n a r y

e v e n t s a n d

m o r t a l i t y f r o m

C 9 :

n o . p e r - 3 3 3 3 3

3 3

i n c i d e n c e o f c o r o n a r y e v e n t s n o . o f c a s e s p e r - 3 3 3 3 3

m o r t a l i t y f r o m C 9 : n o . p e r - 3 3 3 3 3

D e y )

p r e v a l e n c e o f s m o k i n g <

3

- 3

* 3

# 3

5 3

2 3

+ 3

3

4 3

3

p

r e

v

a

l e

n

c

e

o

f

s

m

o

k

i n

g

I

<

C h i n a M i n l a n d 0 e r m a n y J u s s i a / c o t l a n d 7 / A

/ource) %ritish 9eart Moundation 9ealth Bromotion Jesearch 0roup www.heartstats.org

'a( !he diagram above shows that the relationship between the incidence ofcoronary events and the mortality from C9: is not the same in all the countriesshown.

/uggest three reasons why this relationship is not the same.

- ......................................................................................................................

.........................................................................................................................

* ......................................................................................................................

.........................................................................................................................

# ......................................................................................................................

.........................................................................................................................

"#$



23/92

'b( 7sing the information in the diagram, describe the evidence to suggest thatsmoking is not the only factor involved in causing heart disease.

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

"*$

'c( :escribe three steps a go'ernment might take to try to reduce the mortality fromC9:.

- ......................................................................................................................

.........................................................................................................................

* ......................................................................................................................

.........................................................................................................................

# ......................................................................................................................

.........................................................................................................................

"#$

"!otal 4 marks$



24/92

18. %elow is a diagram showing the structure of a typical antibody.

h i n g e

r e g i o n

c o n s t a n t

r e g i o n

h e a v y

p o l y p e p t i d e

c h a i n

l i g h t

p o l y p e p t i d e

c h a i n

d i s u l p h i d eb r i d g e

b i n d i n g

s i t e

'a( 8ame the type of cell that produces antibodies.

.........................................................................................................................

"-$

'b( 'i( /tate one function for each of the component parts listed below.

binding site .............................................................................................

................................................................................................................

disulphide bridge ....................................................................................

................................................................................................................

constant region ......................................................................................

................................................................................................................

hinge region ...........................................................................................

................................................................................................................

"5$



25/92

'ii( Explain why the part of the antibody molecule incorporating the binding siteis often called the variable region.

................................................................................................................

................................................................................................................

................................................................................................................

................................................................................................................

"*$

"!otal marks$

19. !he figure below shows the concentration of antibodies in the blood following a first

infection by a pathogen on day 3.

- 5 3

- * 3

- 3 3

4 3c o n c e n t r a t i o n

o f a n t i b o d i e s

a r b i t r a r y u n i t s + 3

5 3

* 3

3

t i m e d a y s

+ 3 3 4 3 3 - 3 33 - 3 * 3 # 3 5 3 2 3



26/92

'i( Explain why there is a delay between the (irst infection by the pathogen and theappearance of antibodies in the blood.

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

"*$

'ii( >n the figure above, draw a curve to show the expected concentration ofantibodies in the blood following a second infection of the same pathogen atday #3.

"*$"!otal 5 marks$

20. &alaria is caused by the parasite &lasmodium which is a single6celled protoctist. At onestage in the life cycle the parasites reproduce asexually within human red blood cells.

'i( :escribe how &lasmodium reproduces asexually.

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

"*$



27/92

'ii( /tate two advantages of asexual reproduction to a parasite such as &lasmodium.

- ......................................................................................................................

.........................................................................................................................

* ......................................................................................................................

.........................................................................................................................

"*$

"!otal 5 marks$

21. !he table below shows data from research investigating the presence of pesticide'insecticide and herbicide( residues in drinking water in the 7D from -2 to -4.

pesticidenumber of samples

analysed over 5 years< of samples over

safe limit for drinking

insecticide lindane *** 3.

::! -32 3.*

herbicide mecoprop **4- *.

atraine ### -3.*

:ata from 0uide to a 0reen Blanet, edited by Lules Bretty, pp.-2, 7niversity of Essex, *33*

'a( ::! was banned from use in the 7D in -4+.

/uggest why ::! was detected in drinking water more than ten years followingthe ban.

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

"*$



28/92

'b( !he table above shows that a greater percentage of samples analysed forherbicide residues were over the safe limit than those analysed for insecticideresidues.

/uggest why farmers used larger quantities of herbicides than insecticides.

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

"#$

"!otal 2 marks$

22. Aphids are pest species which farmers control using insecticides. It is important thatfarmers use the correct dose of the active ingredient in an insecticide on their crops toensure effective control. !he following table shows doses that a farmer would apply toa crop of barley to control aphids.

active ingredient dose cm# ha

-

deltamethrin *23

dimethoate 452

tau6fluvalinate -23

N6cyhalothrin and pirimicarb -333

chlorpyrifos 33

:ata from 0uide to a 0reen Blanet, edited by Lules Bretty, pp.-2,7niversity of Essex, *33*

7sing the table state which active ingredient is the most toxic to aphids and explainyour answer.

..................................................................................................................................

..................................................................................................................................

..................................................................................................................................

..................................................................................................................................

"!otal) * marks$



29/92

2. !he effect of diet on cancer mortality is partly due to its effect on obesity. >besity isdefined as having a %ody &ass Index '%&I( over *5.. %&I is calculated by thefollowing formula.

%&I 1 ( )( ) *mheight

kgmassbody

!he figure below shows the effect of %&I on the relative risk of dying from cancer. 8on6obese people with a %&I of -4.2*5. are assigned a baseline risk of -.

* . 3

- . 2

- . 3

3 . 2

3 . 3- 4 . 2 6 * 5 . * 2 . 3 6 * . # 3 . 3 6 # 5 . # 2 . 3 6 # . 5 3 . 3≥

r e l a t i v er i s k

o f d e a t h

f r o m c a n c e r

% & I

m e n

w o m e n

O 8ational >besity Morum, Jeproduced by kind permission of the 8ational >besity Morum

'i( Calculate the %&I of a woman -. m tall with a mass of -32 kg.

Answer 1 .........................................................

"*$



30/92

'ii( 7se the figure above to explain the likelihood of this woman dying from cancer.

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

"*$

"!otal 5 marks$

2!. !he table below shows a number of categories of disease, a definition of each categoryand one example of a disease that fits into each category.

Complete the table.

category definition of disease category one example

deficiency diseases caused by poor diet scurvy

.................................diseases caused by a genetic faultpassed from the parents

cystic fibrosis

degenerative

...............................................................

...............................................................

...............................................................

9untington@s disease

infectiousdiseases that are transmitted by apathogenic organism which invades thebody

................................

................................. diseases caused by changes to the mind schiophrenia

physical...............................................................

...............................................................

asthma

"!otal 2 marks$



31/92

2". Epidemiology is the study of patterns of disease and the factors that affect theiroccurrence and spread.

/tate three ways in which members of the medical profession can use information

about how diseases spread.

- ...............................................................................................................................

..................................................................................................................................

* ...............................................................................................................................

..................................................................................................................................

# ...............................................................................................................................

..................................................................................................................................

"!otal # marks$

2%. !he different parts of the gaseous exchange system, such as the bronchi, showstructural adaptations to their functions. !he diagram below shows a section throughthe wall of a bronchus as seen with a light microscope.

c i l i a g l o b l e t c e l l s

c a r t i l a g e s m o o t h m u s c l e



32/92

'a( 'i( /tate one function for each of the following components of the bronchuswall.

goblet cell ...............................................................................................

................................................................................................................

cartilage .................................................................................................

................................................................................................................

"*$

'ii( /tate two ways in which the structure of the wall of the bronchus would bedifferent in a long6term smoker.

- .............................................................................................................

................................................................................................................

* .............................................................................................................

................................................................................................................

"*$

'b( 0aseous exchange occurs across the walls of the alveoli.

Explain why the walls of the alveoli contain elastic fibres.

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

"*$



33/92

'c( >ne feature of the disease emphysema is that the alveoli lose their elasticity.

Explain the effects of this loss of elasticity on the gaseous exchange system of aperson with emphysema.

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

"5$

"!otal -3 marks$



34/92

2&. !he diagram below shows an artery lying on the surface of living heart muscle as seenby an instrument called an endoscope. !he lumen of the artery has become narrowedat the point labelled ).

!he Morum on Ischaemic 9eart :isease.Jeproduced by kind permission of :r 0raham Lackson,

Cardiology 7nit, 0uy@s and /t !homas@ 9ospital.

'i( 8ame the artery shown in the diagram.

.........................................................................................................................

"-$

'ii( Explain how the lumen of the artery has become narrowed at point ).

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

"*$

"!otal # marks$



35/92

28. 'i( /uggest how doctors might treat a patient with narrowing of the arteries thatsupply the heart muscle.

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

"*$

'ii( /uggest two pieces of advice that a doctor might give to such a patient to try toreduce the likelihood of further narrowing of the arteries.

- ......................................................................................................................

.........................................................................................................................

* ......................................................................................................................

.........................................................................................................................

"*$

"!otal 5 marks$

29. 'a( &ilk contains a number of important nutrients including)

K proteins which contain amino acids

K fats which contain fatty acids

K minerals.

8ame two other groups of nutrients found in a balanced diet.

- ......................................................................................................................

* ......................................................................................................................

"*$



36/92

'b( /ome amino acids are known as essential amino acids.

'i( /tate what is meant by the term essential amino acids.

................................................................................................................

................................................................................................................

"-$

'ii( >utline the functions of essential amino acids in the body.

................................................................................................................

................................................................................................................

................................................................................................................

................................................................................................................

"*$

'c( !he photograph below shows a child with kwashiorkor, a form of protein energymalnutrition.

Jeproduced by kind permission of !om : !hacher,&:, www.thachers.org



37/92

'i( :escribe the symptoms of kwashiorkor.

................................................................................................................

................................................................................................................

................................................................................................................

................................................................................................................

................................................................................................................

................................................................................................................

"#$

'ii( Explain why the onset of this disease often occurs between the ages of sixmonths and eighteen months.

................................................................................................................

................................................................................................................

................................................................................................................

................................................................................................................

"*$

"!otal -3 marks$



38/92

0. !he table below shows)

K the percentage of people with 9IFAI:/ in different regions of the world atthe end of *33*

K the number of new infections with 9IF between - and *33* expressedas a percentage of those with 9IFAI:/ at the end of *33*.

region

percentage of peoplewith 9IFAI:/ at the

end of *33*

number of new infectionsbetween - and *33* as< of those with 9IFAI:/ at

the end of *33*

East Asia and Bacific - +

Eastern Europe andCentral Asia

- 2 -+

8orth Africa and&iddle East

- 5

8orth America - -+

/ub6/aharan Africa -2 # 2*

;estern Europe - -2

It has been suggested that 9IFAI:/ is a greater problem in less economicallydeveloped regions than in more economically developed regions.

:escribe the evidence in the table that supports this suggestion.

..................................................................................................................................

..................................................................................................................................

..................................................................................................................................

..................................................................................................................................

..................................................................................................................................

..................................................................................................................................

"!otal * marks$



39/92

1. In this question, one mark is available for the quality of spelling, punctuation andgrammar.

Explain why it is difficult to prevent the spread of 9IFAI:/ and explain why the

increase in the number of cases is so much higher in some parts of the world than inothers.

"$

Puality of ;ritten Communication "-$

"!otal 4 marks$

2. 'a( Complete the following passage.

In >ctober *335, scientists announced successful trials of a malaria vaccine. !he

vaccine was developed from proteins taken from the parasite, ......................................

falciparum. ;hen the proteins enter the body they act as ......................................

which are recognised as foreign by the immune system. !hese foreign proteins activate

lymphocytes called ! cells which then divide to increase in numbers. /ome of these

newly cloned cells become ...................................... cells which attack infected cells in

the liver. >thers become ...................................... cells which release a hormone6like

messenger molecule called a ...................................... . !hese molecules activate %

cells to divide and produce plasma cells. !he % cells also produce

...................................... cells that stay in the body for a number of years. !he result is

an immune system prepared to make a strong attack on the parasite when it enters the

body.

"+$

'b( 8ame the molecules, released by plasma cells, that attack the parasite when itenters the body.

.........................................................................................................................

"-$



40/92

'c( /uggest why it has been difficult to produce a malaria vaccine.

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

"#$

"!otal -3 marks$

. 'a( !he malarial parasite, &lasmodium, and its vector, the mosquito, are botheukaryotes.

!he treatment and control of malaria is difficult because &lasmodium rapidlydevelops resistance to most anti6malarial drugs as do mosquitoes to insecticides. Also, vaccine production has proved to be very difficult. !he %6cell responsesinduced by experimental vaccines are not yet very effective.

Explain

'i( the genetic basis of resistance in eukaryotesQ

................................................................................................................

................................................................................................................

................................................................................................................

................................................................................................................

................................................................................................................

................................................................................................................

................................................................................................................

................................................................................................................

"2$



41/92

'ii( why producing an effective vaccine against &lasmodium has proved to beso difficult.

................................................................................................................

................................................................................................................

................................................................................................................

................................................................................................................

................................................................................................................

................................................................................................................

"#$

'b( A gene has been identified in several species of &lasmodium which codes for asmall transmembrane protein.

A mutant form of & #er$hei exists in which this protein is not produced. &#er$hei infects mice. !he mutants)

K develop normally in a mosquito and infect the salivary glands in numberscomparable to wild type parasites

K infect mouse liver cells but do not multiplyK do not infect red blood cells.

'i( :escribe one mutation of this gene that could have occurred in & #er$heiso that the encoded protein is not produced.

................................................................................................................

................................................................................................................

................................................................................................................

"*$

'ii( /uggest one reason why mutant & #er$hei do not infect red blood cells.

................................................................................................................

................................................................................................................

................................................................................................................

................................................................................................................

"*$



42/92

'c( It has been suggested that &lasmodium with this mutation could be used as a?whole organism@ vaccine against malaria.

&ice were inoculated with different numbers of mutant &lasmodium and then

given one or two ?booster@ inoculations. !heir protection against infection by wild6type &lasmodium was compared with that of mice that had not been inoculated.!he results of the investigation are shown in the table below.

number of mutant &lasmodium percentage of mice

in initial inoculationin first booster

inoculationin second booster

inoculation

resistant to infection bywild6type &lasmodium

23 333 *2 333 *2 333 -33

-3 333 -3 333 -3 333 -33

-3 333 -3 333 3 3 3 3 3 3

;ith reference to the information in the table and in 'b(, comment on the use ofthis mutant &lasmodium as a ?whole organism@ vaccine.

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

"#$

"!otal) -2 marks$



43/92

!. !he Joyal /ociety for the Brotection of %irds 'J/B%( and the %ritish !rust for>rnithology '%!>( carried out research into the declining populations of farmland birdspecies. In a study carried out from -3 to -4 they found that farmland bird specieshad decreased by up to +4< across rural areas of the 7D.

'i( Changes in farming practices, such as the increased use of pesticides, arehighlighted by the J/B% and %!> as possible causes of this decline in birdspecies.

/uggest how the increased use of pesticides could have caused this decline.

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

"#$



44/92

'ii( An increase in the number of predators, such as magpies and sparrowhawks,has also been suggested as a possible cause for the decline in the populations of farmland bird species.

/uggest why this may not be the cause.

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

"*$

"!otal 2 marks$

". !he 9uman Immunodefficiency Firus '9IF( is spread by exchange of body fluidsbetween an infected person and an uninfected person. !his often occurs as a result ofunprotected sexual intercourse. 9IF AI:/ is categorised as an infectious disease.

=isted below are three other categories of disease.

'a( /tate one example of a disease that fits into each category.

mental disease ...............................................................................................

self6inflicted disease .......................................................................................

inherited disease ............................................................................................

"#$



45/92

!he diagram below shows the percentage of people infected with 9IF in different partsof the world at the end of *33*.

8 o r t h A m e r ic a3 . 2 6 - <

C a r i b b e a n- 6 2 <

= a t i n A m e r i c a- 6 2 <

; e s t e r n E u r o p e3 . 2 6 - <

8 o r t h A f r i c a G & i d d l e E a s t3 . 2 6 - <

/ u b 6 / a h a r a n A f r i c a- 2 6 # <

E a s t e r n E u r o p eG C e n t r a l A s i a- 6 2 <

E a s t A s i a G B a c i f i c3 . 2 6 - <

/ o u t h G/ o u t h 6 E a s t A s i a

3 . 2 6 - <

A u s t r a l i a G8 e w H e a l a n d

3 . - <

data from 78AI:/

'b( 'i( Explain why it is useful to collect information, such as that shown in thediagram.

................................................................................................................

................................................................................................................

................................................................................................................

................................................................................................................

................................................................................................................

................................................................................................................

................................................................................................................

"#$



46/92

'ii( !he percentage of people infected with 9IF is much higher in /ub6/aharan Africa than in much of Europe.

/uggest why the percentages are so much higher in /ub6/aharan Africa.

................................................................................................................

................................................................................................................

................................................................................................................

................................................................................................................

"*$

'c( At present there is no cure for 9IFAI:s. Efforts to reduce the spread of 9IFinfection are centred on reducing the chances of a person carrying 9IF passing iton to others.

/uggest how information gained from the 9uman 0enome Broect might be usedto help reduce the spread of 9IF.

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

"*$

"!otal -3 marks$



47/92

%. !he diagram below shows stages in the immune response to invading bacteria.

b a c t e r i a e n g u l f e d b y c e l l s f r o m t h e i m m u n e s y s t e m

r e m o v a l o f a n t i g e n s f r o m b a c t e r i a

a n t i g e n s p r e s e n t e d o n s u r f a c e o f e n g u l f i n g c e l l s

c o r r e c t ! h e l p e r c e l l s a r e s e l e c t e d

r e p r o d u c t i o n o f ! h e l p e r c e l l s

r e l e a s e o f c y t o k i n e s

c y t o k i n e s a c t i v a t e % c e l l s

r e p r o d u c t i o n o f % c e l l s

-

*

#

5

2

+

4

- 3

s o m e % c e l l c l o n e sd i f f e r e n t i a t e t o m a k e

p l a s m a c e l l s

p l a s m a c e l l s m a n u f a c t u r ea n t i b o d i e s

s o m e % c e l l c l o n e sd i f f e r e n t i a t e t o m a k e

% m e m o r y c e l l s

'i( 8ame the type of cell that engulfs the bacteria in stage -.

........................................................................................................................."-$

'ii( /uggest how the antigens are removed from the bacteria in stage *.

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

"*$



48/92

'iii( Explain how the correct ! helper cells are selected in stage 5.

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

"*$

'iv( 8ame the type of cell division used for reproduction of the ! helper cells instage 2.

.........................................................................................................................

"-$

'v( Explain the importance of % memory cells in immunity.

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

"5$

"!otal -3 marks$



49/92

&. :escribe how antibodies act on invading pathogens, such as bacteria or viruses.

..................................................................................................................................

..................................................................................................................................

..................................................................................................................................

..................................................................................................................................

..................................................................................................................................

"!otal * marks$

8. %oth Mig. - and Mig. * are photographs of lung tissue taken through a light microscopeat the same magnification.

*ig. 1



50/92

Lohn %urbridge /cience Bhoto =ibrary

*ig. 2

Mig. - shows healthy lung tissue.Mig. * shows lung tissue damaged by tuberculosis.

'a( 8ame the organism that causes tuberculosis.

.........................................................................................................................

"-$

'b( /uggest how damage to lung tissue in tuberculosis, as seen in Mig. *, is likely toaffect a person with this disease.

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

"*$



51/92

'c( >utline the reasons why tuberculosis has not been eradicated.

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

"2$

"!otal 4 marks$

9. 'a( 8ame two diseases that may be caused by many years of cigarette smoking.

- ......................................................................................................................

* ......................................................................................................................

"*$



52/92

'b( In this question, one mark is available for the quality of use and organisation ofscientific terms.

!he diagram below shows three components inhaled as a result of smoking a

cigarette.

c a r b o n m o n o x i d en i c o t i n e

t a r

:escribe the effects of these three components of cigarette smoke on the body.

"4$

Puality of ;ritten Communication "-$

"!otal -- marks$



53/92

!0. 9aemolytic disease of the newborn can occur if red blood cells are broken down toorapidly.

!his is caused by antibodies, produced by the mother, crossing the placenta into the

fetal circulation.

/uggest how antibodies cause the breakdown of red blood cells in haemolytic diseaseof the newborn.

..................................................................................................................................

..................................................................................................................................

..................................................................................................................................

..................................................................................................................................

..................................................................................................................................

..................................................................................................................................

"!otal * marks$

!1. Jesearchers and medical practitioners calculate the ratio of the total blood cholesterolconcentration '+$( to the concentration of cholesterol carried by one type of lipoprotein,called high density lipoprotein 'D-(. !his ratio is called the +$ D- ratio.

!he !C ) 9:= ratio and the resting systolic blood pressure are both factors which areassociated with the risk of having coronary heart disease 'C9:(.

/ystolic pressure is the pressure in the maor distributing arteries when the left ventriclecontracts.



54/92

!he way in which both the !C ) 9:= ratio and the resting systolic blood pressure areassociated with the risk of C9:, is shown in the figure below.

- 5 . 3# 2 - -

- + .

Date post:	07-Jul-2018
Category:	Documents
Upload:	hamed
View:	217 times
Download:	0 times

AS BIOLOGY OCR A | Every Food and Health Question

Documents