Science>Year 9>Unit 1>Checkpoint 3

Checkpoint 3

This checkpoint tests Block C: herd immunity and vaccination coverage, antibiotics and antivirals and resistance, designing a disease investigation, non-infectious disease, and epidemiology of outbreaks.

SC5-DIS-03Lessons 12-1610 MC3 Short AnswerCheckpoint 3 of 4
CP3

Coverage

This checkpoint assesses your understanding of Block C.

Lesson 12

Herd immunity and vaccination coverage: the herd immunity threshold, R0, protecting the vulnerable.

Lesson 13

Antibiotics and antivirals: how they work, proper use, and antimicrobial resistance.

Lesson 14

Designing a disease investigation: investigable questions, variables, fair tests, and validity.

Lesson 15

Non-infectious disease: cardiovascular disease, type 2 diabetes, obesity, risk factors, and screening.

Lesson 16

Investigating outbreaks: epidemic curves, incidence, contact tracing, and epidemiology.

Checkpoint Standard Strong answers use precise scientific language and connect concepts to real-world examples.
MC Score
0 / 10
SA Score
0 / 12
Q

Test Your Understanding

UnderstandBand 3

1. Herd immunity protects a community because:

AVaccines make every single person completely immune
BPathogens stop mutating once a vaccine exists
CEnough people are immune that the pathogen cannot spread easily to the vulnerable
DAntibiotics are given to everyone in the population
UnderstandBand 3

2. A disease with a higher R0 (basic reproduction number) generally requires:

AA lower vaccination coverage to reach herd immunity
BA higher vaccination coverage to reach herd immunity
CNo vaccination at all, because it spreads too fast
DAntibiotics rather than vaccines
UnderstandBand 4

3. Which statement correctly contrasts antibiotics and antivirals?

ABoth kill viruses by bursting the cell wall
BAntibiotics treat viral infections and antivirals treat bacterial infections
CAntivirals work on any pathogen, while antibiotics work on none
DAntibiotics target bacterial structures, while antivirals interfere with viral replication
UnderstandBand 4

4. Antimicrobial resistance spreads through a bacterial population because:

AResistant bacteria survive antibiotic treatment and reproduce, passing on the resistance
BIndividual bacteria choose to become resistant when threatened
CAntibiotics directly turn bacteria into superbugs
DResistance only appears in patients who skip vaccines
UnderstandBand 3

5. In a fair test, the variable that is deliberately changed by the investigator is the:

ADependent variable
BControlled variable
CIndependent variable
DRandom variable
ApplyBand 4

6. A student tests whether hand-washing reduces bacteria, but uses a different sink, soap, and time for each trial. The main weakness in this investigation is that it is:

AToo expensive to run
BNot valid, because variables other than hand-washing were not controlled
CUnethical, because it studies bacteria
DPerfectly valid, because it was repeated several times
UnderstandBand 4

7. Which of the following is a non-infectious disease?

ATuberculosis
BInfluenza
CCOVID-19
DType 2 diabetes
UnderstandBand 4

8. An epidemic curve is a graph that shows:

AThe number of new cases of a disease over time during an outbreak
BThe price of medicines over several years
CThe genetic sequence of a pathogen
DThe body temperature of a single patient each hour
ApplyBand 4

9. A country has high rates of type 2 diabetes and cardiovascular disease. Which public health strategy is most appropriate?

AMass vaccination of the whole population
BQuarantine of infected people
CPromoting healthy diet and exercise, and screening for early signs
DDeveloping new antibiotics
AnalyseBand 5

10. During an outbreak, health officials use contact tracing mainly to:

ADecide which antibiotics to manufacture next year
BIdentify who may have been exposed so the chain of transmission can be broken
CMeasure the body mass index of every patient
DProve that the disease is non-infectious

Short Answer Questions

UnderstandBand 4

11. Explain how natural selection leads to antibiotic resistance. Include the roles of mutation, selection pressure, and reproduction in your answer. 4 MARKS

Answer in your book.
ApplyBand 4

12. A student wants to investigate whether a hand sanitiser reduces the number of bacteria on hands. Describe how they could design a valid and fair investigation. Identify the independent, dependent, and one controlled variable. 4 MARKS

Answer in your book.
AnalyseBand 5

13. During an outbreak, epidemiologists track new cases on an epidemic curve and use contact tracing. Explain how these tools, together with high vaccination coverage and herd immunity, help control the spread of an infectious disease. 4 MARKS

Answer in your book.

Review & Reflect

✓ I can explain...

  • How herd immunity and vaccination coverage protect a community
  • How antibiotics and antivirals work and why they differ
  • How natural selection drives antimicrobial resistance
  • How to design a valid and fair disease investigation
  • Why non-infectious diseases need different prevention strategies
  • How epidemiologists use epidemic curves and contact tracing

⚠ I need to review...

  • How the herd immunity threshold relates to R0
  • Identifying independent, dependent, and controlled variables
  • The risk factors for cardiovascular disease and type 2 diabetes
  • How incidence and contact tracing reveal an outbreak

Mark checkpoint as complete

Tick when you have finished all questions and reviewed your answers.