8/18/2019 Bio 2008 P2 (2)

1/11

FORM TP 2008043

SECONDARY EDUCATION CERTIFICATE

EXAMINA TION

1.   This pa per consists of SIX questions in two sections. Answer ALL

questions.

2. For Section A, wr ite your answers in the spaces provided in this

 book let.

5. At the end of the examination, attach your question booklet to your 

answer booklet and return them to the Supervisor.

Copyright   ©   2006   Cari b bean   Examinations   Council   ®.

All   rights   reserved .

HOLY FA}T!-~CONVENT

f i  i : N A L

LIBRARY

8/18/2019 Bio 2008 P2 (2)

2/11

The pie charts in Figure 1 show the results of an investigation by a student on equal

volumes of   two samples of soil.

(ii) How   do you   account   f or   the d if f erence in the proportion of air in Samples A

and   B?

8/18/2019 Bio 2008 P2 (2)

3/11

(b)   The student carried   out a fur ther   investigation on the soil in which 100 cm3 of water was

 poured on each of the soil samples, A and B.   The water which drained from each soil

sample was collected in measuring cylinders. Figure 2 shows diagrams of the two

cylinders in which the water that d r ained   through each soil sample was collected.

(ii) Which   measuring cylind er   r epr esents d rainage from Sample B? Give a reason

for your answer .

H O L Y F A i" h 1 C O N V EN T

f 1 ENAL

\ LIBRARY

8/18/2019 Bio 2008 P2 (2)

4/11

8/18/2019 Bio 2008 P2 (2)

5/11

(c) Apart from the components shown in the pie chart in Figure 1, soil also contains living

organisms.   Six soil organisms are shown in Figure 3.

~.- .

(i)   Identify TWO features of the organisms observed in Figure 3 which could be

used to classify them.

(ii) Name ONE group of soil organisms that   is im portant in the recycling of soil

nutrients.

(iii) Organisms 1 and 3 in Figure 3 are usually found under stones or   leaf   litter .

Suggest TWO reasons why these organisms are found in this  type of habitat.

HO L Y   f P.ll   H   C O N V E N Tl I ENAL

LIBRARY

8/18/2019 Bio 2008 P2 (2)

6/11

(iv) To investigate the number in  the   population   of   Organism 5 that occurs in  its

habitat:

8/18/2019 Bio 2008 P2 (2)

7/11

On the d iagram in Figure 4,  label EACH of the parts   numbered 1, 2, 3 and 4.

(4 marks)

State ONE function of EACH of the parts labelled 2 and 4.

Part 2:

(ii) How does movement   at   a partially movable joint differ f r om movement at the

elbow joint?

On the stylised d iagram   in  Figure   5,   draw a representation   of a pair   of antagonistic

muscles for   f lexing and extending the  arm.   (2 marks)

Cd) Many   old er persons   r eplace   their hi p bone to retain their ability to walk. Suggest TWO

reasons   why the hip bone can lose its locomotory function.

(4 marks)

Total 15 marks

GO ON TO THE NEXT PAGE

8/18/2019 Bio 2008 P2 (2)

8/11

Figure 6 is a diagram of a dividing cell of an organism which has a diploid chromosome

number of 4.

(i) On the diagram in Figure 6, write the name of the structures labelled I and II.

(2 marks)

How many chromosomes would there be in the daughter cells produced in the

cell division illustrated in Figure 6?

8/18/2019 Bio 2008 P2 (2)

9/11

(c) Suggest ONE reason why it is possible to successfully   transf er   genes   fr om one   species

to another, yet species under normal conditions do not generally interbreed.

8/18/2019 Bio 2008 P2 (2)

10/11

(ii)   Using an a p pr o priate diagram,   show how a plant or animal  may belong   to mor e

than   one food chain.

(iii)   Ex plain why the number of organisms decreases at the successive trophic

levels.   ( 8 marks)

(b) Biological control usually involves the introduction of  new species to an ecosystem to

reduce or control   the po pulation of organisms consider ed to be pests.

Id entif y   ONE relationship that is important   in biological   control and explain

how this relationship functions   in biological   control.

(ii) Suggest TWO reasons why biological control is a preferred method of reducing

 pest po pulations   compared to the use of pesticides.   ( 7   marks)

With the aid of a fully annotated diagram,   ex plain how air reaches   the lungs   and 

oxygen is absorbed into the blood stream.

(ii) Suggest why it is  important for human blood to have a specialised   ty pe of cell

for oxygen absorption.   (9 marks)

The effect of smoke emission from factories on plant   leaves   is sometimes compar ed to

the eff ect   of cigarette   smoke on human lungs.   Suggest   TWO reasons why this compar i-

son is a p pro priate.   (4 marks)

(c)   Many governments have passed legislation   to reduce   the amount of cigarette smoking

in public.   Explain why governments should consider it their responsi bility to reduce

smoking in public. ( 2 marks)

8/18/2019 Bio 2008 P2 (2)

11/11

(ii) Identify TWO diseases from which   the bod y   CA NNOT   ef f ectively defend 

itself .

(iii) For any ONE disease you identified at (a) (ii), explain why it is difficult for the

 body to defend itself from that disease.   ( 8 marks)

Antibiotics are a group of drugs   that   is used to help the  bod y   fight   diseases   caused by

certain organisms. Doctors ad vise their patients   to take   an entire cour se of  antibiotics

only when and as prescribed .   However, many people do not follow the d octor's   advice

and  some of these drugs have been found to be no longer ef f ective.

Suggest TWO biological and TWO   social   implications of the improper use of 

antibiotics. ( 4 mark s)

(c)   Alcohol   is sometimes consid er ed an a bused drug.   Ex plain   why this   may be an

appropriate descr i ption. ( 3 mar  k s)

HOLY [-.; ",C;'NENT

P€1'JAL