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Science questions, chapter 4
Nama / NameKelas / ClassTarikh / Date

Human health

44 marks. Use Practice to check each answer as you go, or Exam to answer everything against the clock first.

Section A: objective questions

12 marks
Choose the best answer for each question.
1

Question 1

Which of the following is a non-infectious disease?
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B
Diabetes is caused by genetic factors or lifestyle and cannot be passed from one person to another. Tinea, cholera and dengue fever are caused by pathogens.
For the teacher: Remembering, low difficulty, standard 4.1.1
Textbook p. 76
2

Question 2

Which disease is spread through the air by droplets?
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C
Tuberculosis is an airborne disease. Typhoid is spread by contaminated food and water, malaria by Anopheles mosquitoes and leptospirosis by rats.
For the teacher: Understanding, low difficulty, standard 4.1.2
Textbook p. 77
3

Question 3

Which pair of vector and pathogen is correct?
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A
Rats carry Leptospira bacteria. Dengue and Zika are spread by Aedes mosquitoes, and Plasmodium (malaria) by Anopheles mosquitoes.
For the teacher: Remembering, medium difficulty, standard 4.1.3
Textbook p. 79
4

Question 4

After a flood, many villagers have diarrhoea and vomiting. Which action is the best way to prevent the disease from spreading further?
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D
Diarrhoea and vomiting after a flood suggest a waterborne disease such as cholera. Boiling drinking water and washing hands break the spread. Fogging, thick clothes and mosquito nets are against mosquito vectors.
For the teacher: Applying, medium difficulty, standard 4.1.2
Textbook p. 78
5

Question 5

Which of the following is the second line of defence of the human body?
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C
White blood cells that engulf and digest pathogens by phagocytosis are the second line. Skin and mucous membrane are the first line; antibodies are the third.
For the teacher: Understanding, low difficulty, standard 4.2.1
Textbook p. 83
6

Question 6

What is an antigen?
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B
An antigen is a foreign substance, such as a pathogen or a toxin molecule, that stimulates the body to produce antibodies. Option A describes an antibody and option C an antiserum.
For the teacher: Remembering, low difficulty, standard 4.2.2
Textbook p. 83
7

Question 7

Diagram 1 shows the antibody concentration in the blood of a baby from birth. The baby is breast-fed and has not been given any injection. What type of immunity is shown?
Graph: the baby's antibody concentration starts at 70% at birth and falls steadily, dropping below the immunity level of 40% between months 2 and 3
Diagram 1
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D
The antibodies are already present at birth and no injection was given, so they came from the mother through the placenta and breast milk (natural). The baby's own body did not make them (passive), and they fall below the immunity level within a few months.
For the teacher: Analysing, medium difficulty, standard 4.2.4
Textbook p. 86
8

Question 8

What does a vaccine contain?
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A
A vaccine contains antigens from a part or the whole of a weakened or dead virus or bacterium. They stimulate the body to make its own antibodies.
For the teacher: Understanding, low difficulty, standard 4.2.3
Textbook p. 84
9

Question 9

Which statement about active immunity is correct?
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D
In active immunity the body makes its own antibodies and the immunity lasts long. Options A, B and C describe passive immunity.
For the teacher: Understanding, medium difficulty, standard 4.2.4
Textbook p. 86
10

Question 10

Diagram 2 shows the antibody concentration in the blood of a person after exposure to virus A. On which day did the antibody concentration first reach the immunity level?
Graph of antibody concentration against days after exposure to virus A. The curve crosses the dashed immunity level of 40% at day 15 and peaks at 70% on day 20.
Diagram 2
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B
The curve meets the dashed immunity level (40%) at day 15. Day 20 is the peak (70%), and the curve falls back to the immunity level at day 25.
For the teacher: Analysing, medium difficulty, standard 4.2.4
Textbook p. 86
11

Question 11

Which action belongs to the tertiary stage of preventing the spread of infectious diseases?
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A
The tertiary stage controls the vector population (destroying breeding places, fogging) and protects hosts. Immunisation and check-ups are primary; early treatment is secondary.
For the teacher: Applying, high difficulty, standard 4.1.4
Textbook p. 81
12

Question 12

Which of the following is NOT part of the first line of defence?
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C
Tears, nasal hairs and earwax stop or kill microorganisms at the body's entrances (first line). Antibodies are made inside the body and form the third line.
For the teacher: Understanding, low difficulty, standard 4.2.1
Textbook p. 83

Section B: structured questions

32 marks
Answer all questions. Write your answers in the spaces provided.
13

Question 13

Classify each disease as infectious or non-infectious.
[1 mark] (a)Hypertension
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Non-infectious
[1 mark] (b)Leptospirosis
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Infectious
[1 mark] (c)Asthma
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Non-infectious
For the teacher: Remembering, low difficulty, standard 4.1.1
Textbook p. 76
14

Question 14

Typhoid is a disease with fever, intestinal bleeding and red rashes. It is caused by Salmonella typhi bacteria and the bacteria are spread by flies.
[1 mark] (a)What is the fly called in the spread of typhoid?
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Tick each point you got.
[2 marks] (b)Explain how a fly spreads typhoid to a person.
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[1 mark] (c)State one way to control the fly population.
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Any 1 points
Tick each point you got.
For the teacher: Understanding, medium difficulty, standard 4.1.3
Textbook p. 80
15

Question 15

A town has no clean water supply after a flood. Many people suffer from cholera, which is caused by Vibrio cholerae bacteria.
[1 mark] (a)State the way in which cholera is spread.
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Tick each point you got.
[2 marks] (b)Suggest two ways to prevent the spread of cholera.
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Any 2 points
Tick each point you got.
[1 mark] (c)Cholera patients are kept away from other people. State the stage of prevention for this action.
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Tick each point you got.
For the teacher: Applying, medium difficulty, standard 4.1.4
Textbook p. 81
16

Question 16

Diagram 3 shows the antibody concentration in the blood of a person who was exposed to virus A.
Graph of antibody concentration against days after exposure to virus A, with a dashed immunity level at 40%
Diagram 3
[1 mark] (a)On which day was the antibody concentration at its highest?
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Tick each point you got.
[1 mark] (b)For how many days was the antibody concentration above the immunity level?
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[2 marks] (c)Is the person protected from virus A on day 10? Explain your answer.
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Tick each point you got.
For the teacher: Analysing, medium difficulty, standard 4.2.4
Textbook p. 86
17

Question 17

Diagram 4 shows two types of immunity, P and Q. Immunity P follows an injection of antiserum at week 0. Immunity Q follows two vaccine doses, at week 0 and week 4.
Immunity P: antibodies rise quickly to 70% and fall below the immunity level by week 4
Immunity P
Immunity Q: antibodies stay low until the second dose at week 4, then rise to over 80% and stay above the immunity level to week 12
Immunity Q
[1 mark] (a)Name immunity P.
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Passive artificial immunity
[1 mark] (b)Name immunity Q.
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Active artificial immunity
[2 marks] (c)State two differences between immunity P and immunity Q.
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Any 2 points
Tick each point you got.
[2 marks] (d)Which immunity gives better long-term protection? Give a reason.
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Tick each point you got.
For the teacher: Evaluating, high difficulty, standard 4.2.4
Textbook p. 86
18

Question 18

Name the type of immunity gained in each case.
[1 mark] (a)Aina had chickenpox when she was six. She has never had it again.
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Active natural
[1 mark] (b)A baby is given the BCG injection.
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Active artificial
[1 mark] (c)A newborn baby receives antibodies from its mother's breast milk.
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Passive natural
For the teacher: Applying, medium difficulty, standard 4.2.4
Textbook p. 86
19

Question 19

The human body defends itself against pathogens in three stages.
[2 marks] (a)State two parts of the body that form the first line of defence.
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Any 2 points
Tick each point you got.
[2 marks] (b)Explain how antibodies fight pathogens.
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Tick each point you got.
For the teacher: Understanding, medium difficulty, standard 4.2.1
Textbook p. 83
20

Question 20

Hafiz's parents did not take him for his scheduled vaccinations. He also sleeps late, is under stress and often stays in a smoky place.
[2 marks] (a)Explain why babies and children need to be immunised.
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Tick each point you got.
[2 marks] (b)Suggest two changes Hafiz should make to strengthen his immune system.
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Any 2 points
Tick each point you got.
For the teacher: Creating, high difficulty, standard 4.2.5
Textbook p. 87