Candidate Number Candidate Name

JUNIOR SECONDARY CERTIFICATE

LIFE SCIENCE 1220/1
WRITTEN PAPER 2 hours 15 minutes

Marks 130 2018

Additional Materials: Multiple-choice answer sheet

Non-programmable calculator
Soft clean eraser
Soft pencil (type B or HB)
Ruler

INSTRUCTIONS AND INFORMATION TO CANDIDATES

SECTION A
• Make sure that you receive the multiple-choice answer sheet with
your Candidate Number on it to answer Section A. For Examiner's Use
• There are thirty questions.
Section B
• Answer all questions.
1
2
SECTION B
3
• Write your Candidate Number and Candidate Name in the spaces
at the top of this page. 4
• Write your answers on the Question Paper in the spaces provided. 5
6
• Answer all questions.
7

• Write in dark blue or black pen. 8

• Use a pencil for diagrams, graphs or rough working. 9
• Do not use correction fluid.
10
• You may use a non-programmable calculator.
• TOTAL
The number of marks is given in brackets [ ] at the end of each question
or part question.
Marker
Checker

This document consists of 26 printed pages.

Republic of Namibia
MINISTRY OF EDUCATION, ARTS AND CULTURE
© MoEAC/DNEA JSC 2018, Life Science [Turn over
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SECTION A
• Answer all questions.
• For each question there are four possible answers, A, B, C and D. Choose the one
you consider correct and record your choice in soft pencil on the multiple-choice
answer sheet.
• If you want to change an answer, thoroughly erase the one you wish to delete.

1 Which cell type is directly affected by HIV?

A lymphocytes
B phagocytes
C platelets
D red-blood cells

2 What initially happens when HIV enters the body?

A HIV reproduces outside the host cell.
B Lymphocytes produce antibodies to HIV.
C Red blood cells carry more oxygen.
D The body's immune system becomes stronger.

3 ELISA is one of the tests used in Namibia to reveal one's HIV status.

What does this test detect?

A antibodies to HIV
B CD4 count
C HIV antigens
D viral nucleic acid

4 Which STD infects the urethra in males and the cervix in females?
A genital herpes
B gonorrhoea
C HIV
D syphilis

5 Tuberculosis is caused by
A a bacterium.
B a fungus.
C a protozoan.
D a virus.

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6 A person may suffer from which condition as a result of the destruction of red
blood cells by plasmodium?
A anaemia
B chicken pox
C polio
D thrush

7 The slow and gradual change in characteristics of species over a long period of
time is called
A classification.
B evolution.
C mutation.
D variation.

8 Exposure to which pollutant reduces the amount of oxygen that the blood is able
to carry?
A carbon monoxide
B dust particles
C nicotine
D tar

9 When exercising, an individual breathes faster in order to

A digest more food.
B drink more water.
C take in more oxygen.
D take in more carbon dioxide.

10 The diagram below shows a ciliated glandular epithelial tissue.

cilia

secreting gland

ciliated cell

In which parts of the respiratory system can this type of tissue be found?
A alveoli and diaphragm
B bronchi and trachea
C bronchioles and alveoli
D diaphragm and bronchi

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11 The blood vessel best described as having a thick muscular and elastic wall, no
valves and a small lumen is the
A aorta.
B capillary.
C pulmonary vein.
D vena cava.

12 Which organ pumps blood through the circulatory system?

A brain
B heart
C lung
D skin

13 The diagram shows the external structure of the human heart.

A
B
C

Which of the labelled vessels supplies the heart muscles with oxygen and glucose?

14 Which component of the blood contains an iron-rich protein?

A plasma
B platelets
C red blood cells
D white blood cells

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15 The diagram shows a portion of a blood vessel.

Is the vessels shown in the diagram a vein or an artery? The vessel is

A an artery because it has a large lumen.
B an artery because it has a thick wall.
C a vein because it has walls made of elastic fibres.
D a vein because it has valves along its length.

16 The change in pulse observed immediately following exercise is a result of

A decreased concentration of carbon dioxide.
B decreased demand for oxygen by muscles.
C increased blood volume.
D increased heart rate.

17 Which diagram correctly shows the flow of blood through the heart?

A C

D
B

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18 All of the following are excreted by the skin, except

A carbon dioxide.
B lactic acid.
C salt.
D water.

19 The tube that delivers urine from the kidney to the bladder is called the
A aorta.
B penis.
C ureter.
D urethra.

20 The sensory neurone receives nerve impulses from the

A brain.
B effector.
C receptor.
D spinal cord.

21 Which gland produces the growth hormone?

A adrenal
B pancreas
C pituitary
D thyroid

22 The diagram shows some of the endocrine glands in a human.

C
D

Which gland produces the hormone that controls the level of glucose in the blood?

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23 The diagram shows the main parts of the human brain.

Which labelled part controls the heartbeat?

24 The human heart is composed primarily of what type of muscle?

A antagonistic muscle
B cardiac muscle
C smooth muscle
D skeletal muscle

25 The diagram shows a cross-section of the male reproductive system.

B
C
D

Which labelled structure produces sperm and testosterone?

26 Which series correctly orders stages in the development of a foetus?

A conception; implantation; ovulation; zygote
B implantation; ovulation; zygote; conception
C ovulation; conception; zygote; implantation
D zygote; implantation; ovulation; conception
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27 A fertilised egg is also known as

A a foetus.
B a zygote.
C an embryo.
D an ovum.

28 The diagram shows a type of contraceptive.

contraceptive

The contraceptive shown, works to prevent pregnancy by preventing

A fertilisation.
B implantation.
C menstruation.
D ovulation.

29 Inheritable mutations can result from exposure of sex organs to all of the
following, except
A certain chemicals.
B gamma rays.
C sunshine.
D X-rays.

30 What is the process when heat from the sun is trapped within the earth's
atmosphere called?
A combustion
B global warming
C greenhouse effect
D ozone depletion
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SECTION B For Examiner’s

Use
• Answer all the questions in Section B.
• Use a pencil when making drawings or drawing graphs.

1 Fig. 1.1 shows components of the immune system.

B (highly magnified)

Fig. 1.1

(a) Identify component A of the immune system.

....................................................................................................................... [1]

(b) Explain how the trachea and the skin protect the body against pathogens.

trachea...........................................................................................................

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

skin................................................................................................................

....................................................................................................................... [2]

(c) Component B forms part of the human circulatory system.

Identify component B.

....................................................................................................................... [1]

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(d) The life cycle of a Plasmodium is described in Table 1.1. For Examiner’s
Use

Table 1.1

Events in the life cycle of a Plasmodium number

• New Plasmodium parasites enter the blood.
• An infected Anopheles mosquito bites the
human and transmits the Plasmodium parasite.
• Plasmodium parasite reproduces in the liver.
• The Anopheles mosquito sucks in blood
containing the Plasmodium parasite.
Put the numbers 1- 4 next to the corresponding event, in order to reflect the
correct order of events in the life cycle of a Plasmodium. [4]

(e) During an immunisation campaign babies are vaccinated against the

polio virus.

(i) Describe the effects of this vaccine on the baby's immune system.

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

................................................................................................................ [1]

(ii) State how this vaccine affects the baby's immunity to future exposure
against polio.

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

................................................................................................................ [1]

[10]

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2 Fig. 2.1. shows the major levels of classification in their hierachical order. For Examiner’s
Use

kingdom

phylum

class

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

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

genus

species

Fig. 2.1

(a) Complete Fig. 2.1 by filling in the missing levels. [2]

(b) Use the organisms listed below to construct a cladogram to show their
relationships.

an owl, a chicken, a goat

[3]

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(c) Fig. 2.2 shows five types of insects. Use the key to identify them. For Examiner’s
Use
Complete Table. 2.1.

E A

B D C

Fig. 2.2

1 (a) wings present go to 2

(b) wings absent ant
2 (a) has one pair of wings go to 3
(b) has two pairs of wings go to 4
3 (a) legs not as long as body housefly
(b) legs longer than body mosquito
4 (a) wings shorter butterfly
(b) wings longer dragonfly

Table 2.1

insect name
A
B
C
D
E

[5]
[10]

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3 Fig. 3.1 shows a water snail. For Examiner’s

Use

Fig. 3.1

(a) Draw an enlarged diagram of the water snail and label the antenna.

[3]

(b) Assuming that the actual size of the water snail is 33 mm and your drawing
is 58 mm, calculate the magnification.

[2]

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(c) Organisms can either have prokaryotic or eukaryotic cells. For Examiner’s
Use

(i) Define the term cell.

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

................................................................................................................ [1]

(ii) Compare two differences between prokaryotic and eukaryotic cells.

prokaryotic cells eukaryotic cells

1 ................................................. .....................................................

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

2 ................................................. .....................................................

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

[2]
(d) Fig. 3.2. shows part of a cell.

Fig. 3.2.

(i) Identify the structure shown in Fig. 3.2.

................................................................................................................ [1]

(ii) Underline the term which best describes the permeability of this
structure.

fully selectively [1]

[10]

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4 Fig. 4.1 shows an experiment done by some Grade 10 learners. Two potato For Examiner’s
Use
chips of the same size (10 cm long,1 cm broad and 1 cm wide) were placed into
two different beakers.

Beaker A was filled with distilled water and beaker B was filled with a
concentrated salt solution. The experiment was left for about 3 hours.

A B

distilled water
potato chips concentrated salt solution

Fig. 4.1

(a)  (i) Describe what happened to the size of the potato chips in beaker A and
in beaker B.

A.............................................................................................................

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

B.............................................................................................................

................................................................................................................ [2]

(ii) Explain what causes the changes you mentioned in (a) (i).

A 1 .......................................................................................................

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

2 ........................................................................................................

........................................................................................................ [2]

B 1 .......................................................................................................

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

2 ........................................................................................................

........................................................................................................ [2]

(iii) Suggest what happened to the level of the water in beaker A.

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

................................................................................................................ [1]

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(iv) Name the process that has taken place in this experiment. For Examiner’s
Use

................................................................................................................ [1]

(v) State two significances of this process in organisms.

1..............................................................................................................

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

2..............................................................................................................

................................................................................................................ [2]

[10]

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5 Fig. 5.1 shows structural characteristics of monocotyledons and dicotyledons. For Examiner’s
Use

C
E

Fig. 5.1

(a)  (i) Sort the features into the class to which they belong.

Record your answer in the table below. Write only the correct letters
A - E in the appropriate column in Table 5.1.

Table 5.1

monocotyledons dicotyledons

[5]
(ii) State the phylum to which monocotyledons and dicotyledons belong.

................................................................................................................ [1]

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(b) Characteristics of organisms from various kingdoms are described. For Examiner’s
Use

State the kingdoms to which the organisms belong.

(i) They are made up of mycelium or hyphae.

................................................................................................................ [1]

(ii) They may have a backbone.

................................................................................................................ [1]

(iii) They have a cell wall made of chitin and have nuclei in their cells.

................................................................................................................ [1]

(iv) They are unicellular prokaryotes and cause diseases.

................................................................................................................ [1]

[10]

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6 Fig. 6.1 shows different types of food. For Examiner’s

Use

Fig. 6.1

(a) Name the sources of protein-rich food from Fig. 6.1 that are available to a
vegetarian who

(i) will eat animal products but not meat itself.

................................................................................................................ [1]

(ii) will only eat plants and their products.

................................................................................................................ [1]

(b) Give two reasons why all diets must contain proteins.

1.....................................................................................................................

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

2.....................................................................................................................

....................................................................................................................... [2]

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(c) Suggest a diet that would meet the particular needs of a For Examiner’s
Use

(i) 2 year old child.

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

................................................................................................................ [1]

(ii) male athlete.

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

................................................................................................................ [1]

(d) Fig. 6.2 shows a person suffering from a deficiency disease common in
humans.

Fig. 6.2

(i) Identify the disease.

................................................................................................................ [1]

(ii) Name the mineral that is lacking in the diet of this person.

................................................................................................................ [1]

(iii) State two ways in which this disease can be prevented.

1 ............................................................................................................

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

2 ............................................................................................................

............................................................................................................ [2]

[10]

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7 Fig. 7.1. shows part of the human respiratory system. For Examiner’s
Use

Fig. 7.1

(a)  (i) On Fig. 7.1 draw one label line and label the bronchus. [1]

(ii) Explain the role of the cartilage in the trachea.

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

................................................................................................................ [1]

Fig. 7.2 shows an alveolus.

airflow blood flow

CO2
O2

B
A

Fig. 7.2

(b)  (i) Identify cell A and blood vessel B.

cell A.......................................................................................................

blood vessel B........................................................................................ [2]

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(ii) Name the process by which gases move in and out of the blood. For Examiner’s
Use

................................................................................................................ [1]

(c) Gaseous exchange structures in mammals are lungs.

State and discuss the significance of four features of gaseous exchange
structures in animals for the maintenance of life.

1.....................................................................................................................

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

2.....................................................................................................................

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

3.....................................................................................................................

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

4.....................................................................................................................

....................................................................................................................... [4]

(d) Name one effect of cigarette smoke on the respiratory system.

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

....................................................................................................................... [1]

[10]

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8 Fig. 8.1 shows stages leading to pregnancy. For Examiner’s

Use

3. The zygote divides

4. After several hours, by mitosis.
5. The cells in the ball a ball of cells is formed.
keeps dividing as it moves
down the oviduct. It is
now called an embryo.

placenta forming 1. Ovulation. A

mature follicle bursts
and releases an egg
cell into the oviduct.
6

Fig. 8.1

(a)  (i) Name and describe the process taking place at stage 2.

name....................................................................................................... [1]

description..............................................................................................

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

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

................................................................................................................ [2]

(ii) Identify the process taking place at stage 6.

................................................................................................................ [1]

(b) Discuss two functions of the uterus in the development of the foetus.

1.....................................................................................................................

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

2.....................................................................................................................

....................................................................................................................... [2]

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(c) Discuss two advantages of family planning. For Examiner’s

Use

1.....................................................................................................................

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

2.....................................................................................................................

....................................................................................................................... [2]

(d) Name one argument that supports the legalisation of abortion.

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

....................................................................................................................... [1]

(e) Fig. 8.2 shows the major glands in the human body.

Fig. 8.2

Draw a label line to the gland that produces the female sex hormones and
name the gland. [1]

[10]

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9 (a) Define the term chromosome. For Examiner’s

Use

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

....................................................................................................................... [1]

(b) Explain, with the aid of a simple diagram, (a genetic diagram with labels)
how sex chromosomes determine the sex of mammals.

In your answer show what happens to the sex chromosomes when the sex
cells are formed.

[4]
(c) Distinguish clearly between the terms dominant and recessive.

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

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

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

....................................................................................................................... [2]

(d) The inheritance of blood groups in humans is an example of a variation

caused by co-dominant genes.

(i) What is meant by the term co-dominance?

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

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

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

................................................................................................................ [2]

(ii) Which blood group is a result of co-dominant genes in humans?

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

................................................................................................................ [1]

[10]

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10 The combustion of wood, petroleum and natural gas are activities occurring on For Examiner’s
Use
a daily basis.

(a)  (i) Name the main gas produced during the combustion process.

................................................................................................................ [1]

(ii) State the process that increases temperatures worldwide as a result

of an increase in the gas mentioned in (a) (i).

................................................................................................................ [1]

(b) Human activities can damage the ozone layer, which causes UV-rays to
reach the earth.

(i) State the name of the gas that can deplete the ozone layer.

................................................................................................................ [1]
(ii) List two items whose use can release this gas into the atmosphere.

1 ............................................................................................................

2 ............................................................................................................ [2]
(iii) Describe how the gas mentioned in (b) (i) depletes the ozone layer.
................................................................................................................

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

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

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

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

................................................................................................................ [3]

(iv) Explain two importances of the ozone layer.

1..............................................................................................................

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

2..............................................................................................................

................................................................................................................ [2]

[10]

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