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Health and Diseases

Health and Diseases — Free MYP4 Biology Practice Questions

1QuestionStructure and Replication of Viruses (Ex: Flu)Concept Practice

2 marks~3 minCriterion A

The diagram shows the structure of the influenza virus, with structure X labelled on the outer surface.

(a) Identify structure X and state its function. [2]

Solutions

2QuestionPathogen-Host InteractionsConcept Practice

2 marks~3 minCriterion D

During the COVID-19 pandemic, scientists determined that the SARS-CoV-2 spike protein binds specifically to ACE2 receptors on human respiratory cells. This structural knowledge was used to develop mRNA vaccines, which instruct host cells to produce harmless spike proteins, triggering an immune response without infection.

Outline one real-world application that directly uses knowledge of viral spike protein–host receptor binding. [1]

Identify one ethical issue arising from the application you described in (a). [1]

Solutions

3QuestionClassification of PathogensConcept Practice

2 marks~3 minCriterion A

The diagram below shows a bacterial cell with several structures labelled.

Identify the structure labelled X. [1]

Explain one reason why structure X is essential for bacterial survival. [1]

Solutions

4QuestionPathogen-Host InteractionsConcept Practice

3 marks~5 minCriterion C

The graph below shows the population of a bacterial pathogen over 14 days in two hosts: one with a healthy immune system and one who is immunocompromised. In the healthy host, the bacterial population peaks at day 4 then declines to near zero by day 10. In the immunocompromised host, the population rises continuously throughout the 14-day period.

Identify the trend shown by the bacterial population in the healthy host between day 4 and day 10. [1]

Explain why the bacterial population follows a different trend in the immunocompromised host compared with the healthy host. [1]

Analyse what the comparison between the two curves suggests about the relationship between the effectiveness of the immune response and the rate of bacterial population growth. [1]

Solutions

5QuestionTypes of Vaccines (Examples of vaccines)Concept Practice

2 marks~3 minCriterion C

The table below shows measles cases reported in two populations over ten years. Population A received the MMR vaccine (live attenuated); Population B received no vaccine.

Year	1	2	3	4	5	6	7	8	9	10
Population A (vaccinated)	120	90	75	55	40	25	18	12	9	6
Population B (unvaccinated)	200	270	340	400	480	560	630	700	780	850

Identify the overall trend in measles cases for each population, and describe how the two trends compare. [1]

Explain one reason why the data for Population A may not follow a perfectly smooth downward pattern. [1]

Solutions

6QuestionTypes of Vaccines (Examples of vaccines)Concept Practice

2 marks~3 minCriterion A

The diagram shows two methods of preparing vaccines. Diagram A shows a pathogen treated with heat or chemicals so it can no longer cause disease. Diagram B shows a pathogen grown repeatedly in a laboratory until it becomes too weak to cause disease in a healthy person.

Identify the type of vaccine shown in Diagram A and state one disease it prevents. [1]

Identify the type of vaccine shown in Diagram B and state one disease it prevents. [1]

Solutions

7QuestionImpact of Diet on HealthConcept Practice

2 marks~3 minCriterion A

The diagram below shows a villus from the small intestine, with structures labeled X visible on the surface of the epithelial cells.

Identify the structures labeled X. [1]

Explain how these structures increase the efficiency of nutrient absorption in the small intestine. [1]

Solutions

8QuestionStructure and Replication of Viruses (Ex: Flu)Assessment Practice

6 marks~9 minCriterion B

A patient is infected with influenza virus. The number of virus particles (virions) in their respiratory tract is measured every 12 hours.

Time (hours)	0	12	24	36	48	60
Virions (millions)	0.1	0.2	0.4	0.8	1.6	3.2

Describe the pattern of viral growth shown in the data, with reference to specific values. [2]

Deduce the number of virions at 72 hours, explaining how the data supports your answer. [2]

A clinician states: "If this growth pattern continued unchecked, the patient would have over 100 million virions by day 5." Analyse whether this claim is correct, and identify one biological reason why this growth rate cannot continue indefinitely in a real infection. [2]

Solutions

9QuestionClassification of PathogensAssessment Practice

4 marks~6 minCriterion D

The diagram shows two bacterial cell walls, labelled A and B. Cell wall A has a thick, multi-layered peptidoglycan region with no outer membrane. Cell wall B has a thin peptidoglycan region sandwiched between an inner plasma membrane and a lipid-rich outer membrane.

State which cell wall (A or B) is Gram-positive and which is Gram-negative. [1]

Explain how the structural differences between cell walls A and B produce different colours after Gram staining. [2]

Analyse why identifying a bacterium as Gram-positive or Gram-negative is important when a clinician selects an antibiotic treatment. [1]

Solutions

10QuestionStructure and Replication of Viruses (Ex: Flu)Assessment Practice

4 marks~6 minCriterion A

The diagram shows the structure of the influenza virus with four labelled parts: A) Hemagglutinin (HA) spikes, B) Neuraminidase (NA) spikes, C) Lipid envelope, D) RNA segments.

(a) State the role of hemagglutinin spikes (Label A) in viral infection. [1]

(b) Explain how neuraminidase spikes (Label B) and the lipid envelope (Label C) each contribute to a different stage of the viral life cycle. [2]

(c) Analyse how the segmented RNA (Label D) of influenza, compared with a non-segmented viral genome, could increase the rate at which new viral strains emerge in a human population. [1]

Solutions

11QuestionPathogens: Bacteria, Viruses, Fungi, and ParasitesAssessment Practice

4 marks~6 minCriterion C

The diagram shows four pathogens and their transmission routes: influenza virus (respiratory droplets), norovirus (contaminated food/water), MRSA (direct skin contact), and malaria parasite (mosquito vector).

State the difference between direct and indirect transmission of a pathogen. [1]

Describe how influenza virus is transmitted from an infected person to an uninfected person. [1]

Evaluate the effectiveness of handwashing as a public health measure by analysing which transmission routes shown in the diagram it would interrupt and which it would not. [2]

Solutions

12QuestionImportance of VaccinationAssessment Practice

8 marks~12 minCriterion D

A city of 10,000 people has 85% measles vaccination coverage. The herd immunity threshold for measles is 92–95%. A neighbouring community of 8,000 people has only 60% coverage due to vaccine hesitancy. A traveller infected with measles visits both communities.

Explain why the first community may still experience a measles outbreak despite 85% vaccination coverage. Use the herd immunity threshold in your answer. [2]

Describe two impacts that a measles outbreak in the second community could have on the local healthcare system. [2]

Evaluate the limitations of using herd immunity thresholds to predict disease spread in real-world populations, considering both population structure and the ethical tension between individual choice and collective protection. [4]

Solutions

13QuestionImportance of VaccinationAssessment Practice

4 marks~6 minCriterion A

The diagram below shows two communities. In Community A, 60% of individuals are vaccinated against a disease. In Community B, 95% of individuals are vaccinated. One unvaccinated person is present in each community.

State what is meant by the term herd immunity. [1]

Explain why the unvaccinated person in Community B is protected from the disease. [1]

Analyse why the unvaccinated person in Community A is not protected, comparing the transmission dynamics in both communities to support your answer. [2]

Solutions

14QuestionImportance of VaccinationAssessment Practice

3 marks~5 minCriterion B

The graph below shows vaccination coverage (percent) and disease incidence (cases per 100,000 people) recorded annually over ten years for a single disease.

Year	1	2	3	4	5	6	7	8	9	10
Vaccination coverage (percent)	40	45	50	55	60	65	70	75	80	85
Disease cases per 100,000	200	180	150	120	90	60	35	20	10	5

Identify the relationship between vaccination coverage and disease incidence shown in the graph, using data to support your answer. [1]

Explain how increasing the proportion of vaccinated individuals in a population reduces disease incidence. [1]

Discuss how the pattern of decline in disease cases supports the concept of herd immunity, with reference to a threshold effect visible in the data. [1]

Solutions

15QuestionTypes of Vaccines (Examples of vaccines)Assessment Practice

2 marks~3 minCriterion D

During a measles outbreak in a low-income country, health officials must choose between the MMR vaccine (live attenuated, higher efficacy) and a newer inactivated vaccine (lower efficacy, fewer side effects). Immunocompromised individuals are present in the population, and healthcare infrastructure is limited.

Outline one ethical issue that health officials face when deciding which vaccine to distribute. [2]

Solutions

16QuestionTypes of Vaccines (Examples of vaccines)Assessment Practice

8 marks~12 minCriterion D

In 2019, a community of 10,000 people had a measles vaccination rate of 95%. Following the spread of misinformation, the rate dropped to 82% the following year. The herd immunity threshold for measles is 92–95%. In the subsequent outbreak, 400 unvaccinated individuals contracted measles; 15% of those required hospitalisation.

Explain how herd immunity protects a population, and why the drop from 95% to 82% vaccination coverage triggered a measles outbreak. [2]

Calculate the number of individuals hospitalised during the outbreak. Discuss two societal consequences of this level of disease burden on the affected community. [3]

Evaluate the limitations of relying solely on individual choice to maintain vaccination coverage, and justify one specific public health measure that could have prevented this outbreak. [3]

Solutions

17QuestionHerd Immunity and Disease PreventionAssessment Practice

3 marks~5 minCriterion A

The graph below shows the number of new measles infections over time in a constant-sized population, at vaccination coverages of 50%, 75%, 90%, and 95%.

State the relationship between the percentage of vaccinated individuals and the number of new infections shown in the graph. [1]

Explain how increasing vaccination coverage reduces the transmission of measles through a population. [1]

Identify the vaccination coverage at which herd immunity is achieved for measles and justify why this threshold is higher than for most other infectious diseases. [1]

Solutions

18QuestionImpact of Diet on HealthAssessment Practice

4 marks~6 minCriterion D

A biotechnology company has developed a cell-cultured meat patty marketed as a healthy alternative to beef. Each serving contains 5 g of saturated fat and 800 mg of sodium. An equivalent beef serving contains 17 g of saturated fat and 75 mg of sodium. The production process requires a high-sodium growth medium to support cell proliferation.

Describe one health benefit and one health risk of replacing beef with this cell-cultured meat for a person with hypertension. [2]

Discuss the ethical concern raised by marketing this product as a 'healthy' alternative, given its sodium content. [2]

Solutions

19QuestionNon-Communicable Diseases OverviewAssessment Practice

6 marks~9 minCriterion B

Forced expiratory volume in one second (

\text{FEV}_1

) measures how much air a person can forcibly exhale in one second; a lower value indicates poorer lung function. The table below shows the average annual decline in

\text{FEV}_1

(mL per year) for groups of smokers with different cumulative smoking exposures measured in pack-years.

Pack-years	10	20	30	40
Annual $\text{FEV}_1$ decline (mL/year)	30	45	65	?

Describe the pattern in the relationship between pack-years smoked and annual

\text{FEV}_1

decline shown in the data. [2]

Deduce the annual

\text{FEV}_1

decline for the 40 pack-year group, showing your reasoning clearly. [2]

Analyse how the biological processes of chronic airway inflammation and alveolar destruction explain why the rate of

\text{FEV}_1

decline accelerates with increasing pack-years. [2]

Solutions

20QuestionCauses of Lifestyle DiseasesAssessment Practice

7 marks~11 minCriterion B

A study tracked 20 adults over five years, recording BMI, weekly physical activity (hours), and fasting blood glucose (mmol/L) at the start and end. The table below shows the five-year change in blood glucose for four representative individuals.

Individual A	BMI 22	activity 7 h/week	glucose change $+0.1$ mmol/L
Individual B	BMI 28	activity 3 h/week	glucose change $+1.2$ mmol/L
Individual C	BMI 32	activity 1 h/week	glucose change $+2.5$ mmol/L
Individual D	BMI 35	activity 0 h/week	glucose change $+4.0$ mmol/L

Interpret the pattern relating BMI, physical activity, and blood glucose change. State a general rule that predicts the risk of progressing from prediabetes to Type 2 diabetes based on these two factors. [2]

Deduce the expected five-year blood glucose change for an individual with BMI 30 and 2 h/week of physical activity. Show your reasoning. [2]

Justify why high BMI and low physical activity each contribute to rising blood glucose, and explain why their combined effect is greater than either factor alone. [3]

Solutions

21QuestionNon-Communicable Diseases OverviewAssessment Practice

3 marks~5 minCriterion C

The bar chart below shows the prevalence of Type 2 diabetes in adults aged 40–60 across four BMI categories.

[Bar chart. X-axis: BMI Category — Normal (18.5–24.9), Overweight (25–29.9), Obese Class I (30–34.9), Obese Class II (35–39.9). Y-axis: Prevalence of Type 2 Diabetes (%). Bar heights: Normal 5%, Overweight 12%, Obese Class I 25%, Obese Class II 40%.]

Describe the relationship between BMI category and the prevalence of Type 2 diabetes shown in the graph. Support your answer with data. [1]

Explain one biological mechanism by which excess body fat leads to insulin resistance. [1]

Explain how insulin resistance, if sustained, leads to the development of Type 2 diabetes mellitus. [1]

Solutions

22QuestionCauses of Lifestyle DiseasesAssessment Practice

6 marks~9 minCriterion D

A 45-year-old woman has a strong family history of Type 2 diabetes. Her doctor offers a genetic screening test that estimates her lifetime risk of developing the disease. The test is not perfectly accurate: it can produce false positives (high-risk result for someone who will never develop diabetes) and false negatives (low-risk result for someone who will). Lifestyle factors such as diet and physical activity can significantly modify actual risk.

Explain one positive and one negative health implication for the woman if she receives a high-risk result. [2]

Discuss the ethical implications of sharing her genetic test results with her health insurance company or employer. [2]

Evaluate the reliability of genetic screening as a tool for predicting whether this woman will develop Type 2 diabetes, using evidence from the stem to support your judgement. [2]

Solutions

23QuestionCommunicable DiseasesAssessment Practice

4 marks~6 minCriterion C

The diagram below shows two individuals. Person A has Type 2 diabetes, caused by poor diet and physical inactivity, leading to insulin resistance. Person B has influenza, caused by the influenza virus — a pathogen transmitted through respiratory droplets.

Explain why Type 2 diabetes is classified as a lifestyle disease and influenza is classified as a communicable disease. Refer to the causes shown in the diagram. [2]

Deduce whether each disease can spread from Person A or Person B to another individual. Support your deduction with a reason for each disease. [1]

A public health team wants to reduce the spread of influenza in a school. Evaluate one strategy they could use, considering both its effectiveness and a limitation. [1]

Solutions

24QuestionImpact of Diet on HealthAssessment Practice

8 marks~12 minCriterion A

A 10-year longitudinal study monitored three adult groups, each following a distinct dietary pattern from the start of the study.

Dietary Pattern	Mediterranean / Western / High-Processed
Change in BMI ( $\text{kg/m}^2$ )	$-1.2$ / $+3.5$ / $+5.8$
Change in Systolic BP ( $\text{mmHg}$ )	$-5$ / $+8$ / $+12$
Change in Fasting Glucose ( $\text{mmol/L}$ )	$-0.3$ / $+0.9$ / $+1.6$
Change in HDL Cholesterol ( $\text{mmol/L}$ )	$+0.15$ / $-0.20$ / $-0.35$
Change in LDL Cholesterol ( $\text{mmol/L}$ )	$-0.4$ / $+0.6$ / $+1.0$

The Mediterranean diet is high in unsaturated fats, fibre, and antioxidants. The Western diet is high in saturated fats, refined sugars, and red meat. The High-Processed diet is high in trans fats and added sugars, and low in fibre.

A 40-year-old individual has: BMI

= 28.5\ \text{kg/m}^2

, systolic BP

= 130\ \text{mmHg}

, fasting glucose

= 5.6\ \text{mmol/L}

, HDL

= 1.0\ \text{mmol/L}

, LDL

= 3.2\ \text{mmol/L}

Identify the pattern relating the ratio of unsaturated to saturated fat intake to the changes in HDL and LDL cholesterol across the three diets. [3]

Deduce the individual's predicted values for all five biomarkers after 10 years on the Western diet, and describe the overall health trajectory these values suggest. [3]

Justify the predicted changes in two biomarkers from (b) by explaining the biological mechanisms linking specific components of the Western diet to each change. [2]

Solutions