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TEST CODE

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FORM

TP

2017045

MAY/JUNE 2017

CARIBBEAN EXAMINATIONS

COUNCIL

CARIBBEAN SECONDARY EDUCATION CERTIFICATE@

EXAMINATION

BIOLOGY

Paper

02 _-

General Proficiency

2 hours 30 minutes

DO

NOT

TURN

THIS

PAGE

UNTIL

YOU

ARE TOLD TO

DO SO.

READ THE

FOLLOWING

INSTRUCTIONS CAREFULLY.

1.

This paper consists of SIX questions in TWO sections.

AnswerALL

questions.

2.

Write your answers in the spaces provided in this booklet.

3.

Do NOT write in the margins.

4.

Where appropriate, answers should be illustrated with diagrams.

If

you need to rewrite any answer and there is not enough space to do so on the original page, you must use the extra lined page(s) provided at the back of this

booklet. Remember to

draw

a line through

your original

answer.

If

you use the extra page(s), you MUST write the question number clearly

in

the box provided at the top of the extra page(s) and, where relevant, include

the question

part

beside the answer.

5

6.

Copyright @ 2015 Caribbean Examinations Council

All

rights reserved.

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-4-SECTION

A

AnswerALL

questions

in

this section.

Write your

answers in the spaces provided

in

this booklet.

In an experiment, some students put corn seeds into each of two test tubes labelled A and

B, as shown in Figure

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20"c

10

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Moist cotton wool

Figure 1. Apparatus and materials used

for

experiment

(i)

Write a suitable aim for this experiment.

(2 marks)

(iD

In which of the tubes,

A

or B, would germination most

likely

occur? Give ONE

reason for your answer.

(2 marks)

(iii)

State TWO roles that the moisture from the coffon wool plays in the process

of

germination.

(2 marks)

GO ON TO THE NEXT PAGE

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1.

(a)

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(b) The corn seedlings which germinated are placed

in

a pot and exposed to unidirectional

light as shown in Figure 2.

Figure 2. Corn seedlings exposed to

unidirectional

light

(i)

What type of movement is shown by the plants in Figure 2?

(1

mark)

(iD

State a hypothesis that the students could test by using the apparatus and materials

shown in Figure 2.

(2

(iii)

The students want the seedlings to grow straight towards the ceiling. Suggest how

they could manipulate the apparatus to get this result.

(1

mark)

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-6-(iv)

The seedlings shown

in

Figure 2 use

all

the nutrients stored

in

the cotyledons. Discuss the process by which these plants can make more nutrients.

(4 marks)

(v)

Discuss the processes by which the raw materials required for making nutrients

reach the leaves of the plant.

(4 marks)

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-(c)

(i)

01207020/F 2017 (4 marks)

(ii)

Name ONE plant organ, other than leaves, where starch may be found.

(1mark)

(iii)

Instead of starch, animals store complex carbohydrates such as glycogen. Name

TWO organs in an animal's body which store glycogen.

(2 marks)

Total25

marks

Starch is the most coflrmon carbohydrate that is found in the leaves of green plants' Describe a test that the students could do in the laboratory to investigate whether

starch is present in the leaves of the seedlings.

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Figure 3 represents the Whittaker Five-Kingdom Classification of living organisms LIVING ORGANISMS

Type of cells

Eukaryote

Number of cells

Unicellular

Kingdom Protista _Presence_{of cell}_wall

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No Example: fish Yes Tlpe of Nutrition

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:

yeast

Figure 3.

Whittaker Five-I(ingdom

Classification of

living

organisms

Complete the classification by writing the correct answers at

(i), (ii),

(iii),

(iv)

and (v) in

Figure

3.

(5 marks)

Each kingdom

is

further subdivided into taxa

with

the lowest rank being the level

of

species.

(i)

Define the term 'species'.

(2 marks)

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(i)

Kingdom

Monera

Example: bacteria (iD

(v)

_Kingdom

(iv)

Kingdom

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-9-(ii)

Using the human species as an example, explain

why

physical appearance or morphology isNOT always useful for identiffing organisms belonging to the same

species.

(2 marks)

(iiD

Suggest ONE reason why biologists use the biological concept of species instead of physical characteristics to classiff organisms.

(2 marks)

Some lizards were washed away on a log during a hurricane and landed on a remote island. Several years later, they were classified as a new species.

(i)

Using the biological concept

of

a species, state

TWO

reasons

why

they were

reclassified.

(2 marks)

(ii)

The new species

of

lizards

living in

the mountainous region

of

the island were found to be smaller than those

living

on the lowlands. Suggest TWO reasons

for

this variation.

(2 marks)

Total 15 marks

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(a)

Figure 4 illustrates the events that take place during the human menstrual cycle.

Hormone Y Hormone X

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Identifu Hormones

X

and Y and the event occuning at Z.

x

...

Y

...

Z

(ii)

What is the role of EACH hormone in the menstrual cycle?

Y...

(3 marks)

(2 marks)

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11-(iiD

Name the organ that produces Hormones

X

and Y.

x

(2 marks)

(i")

Discuss the fate of the following structures shown in Figure 4

if

fertillzation

of

the ovum occurs.

Corpus luteum

Uterus lining

(4 marks)

Some contraceptive pills contain hormones. Suggest how this may prevent pregnancy.

(1

mark)

A drug company is developing a male contraceptive

pill.

Suggest THREE ways in which

this could prevent pregnancy.

(3 marks)

Total 15 marks

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(b)

(c)

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-12-SECTION B

Answer

ALL

questions

in

this section.

Write

your

answers

in

the spaces provided

in

this booklet.

(i)

Explain how structures in the human eye control the amount of light that enters

the eye.

(4 marks)

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Jenny enters a dimly

lit

room and cannot see the colours of the furniture until the lights are switched on. Explain how Jenny is able to discern objects in the

dimly

lit

room but cannot see the colours until the lights are switched on.

(5 marks)

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certain

form

of

colour-blindness

is

inherited as a recessive allele carried on the

X

chromosome. It is thus said to be

'X-linked'or'sex-linked'.

Awoman with normal colour vision, whose father is colour-blind, mates with a colour-blind man. What is the chance

of them having colour-blind children? Use a genetics diagram to explain your answer.

Use B for the allele for normal vision and b for the allele for colour-blindness.

(6 marks)

Total 15 marks

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-15-Describe the chemical digestion of carbohydrates, fats and proteins from the mouth

until

they are absorbed in the small intestines.

(6 marks)

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Describe how the body systems work together to assimilate glucose molecules

(4 marks)

(ii)

Explain how the assimilation of glucose by a non-diabetic person differs from that

of a person suffering from diabetes.

(5 marks)

Total 15 marks

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Using a suitable example of EACH, distinguish between a predator-prey relationship and

parasitism.

(6 marks)

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-18-Some environmentalists encourage the practice of introducing predators to an ecosystem to control a population of pests rather than the use of agricultural chemicals.

(i)

Outline THREE advantages and THREE disadvantages of this method ofbiological

control compared to the use of chemicals.

(6 marks)

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Explain how biological control may conhibute to biological evolution through

natural selection in an ecosystem.

(3 marks)

Total 15 marks

END OF TEST

IF

yOU

FINISH BEFORE

TIME

IS CALLED, CHECK YOUR WORK ON THIS TEST.

01207020/F 20t7