Class 9 Practice Level 3 – Why do we fall ill set - 1

Total questions: 29

Which feature of viruses makes them unique compared to other pathogens like bacteria and fungi?

They have cell walls.

They can reproduce independently.

They require a host cell to replicate.

They perform photosynthesis.

None

Which cells are primarily responsible for the adaptive immune response?

Red blood cells

Platelets

B and T lymphocytes

Neutrophils

None

How does horizontal gene transfer contribute to antibiotic resistance in bacteria?

By killing non-resistant bacteria

By mutation during cell division

By transferring resistance genes between bacteria

By increasing the metabolism of bacteria

None

Why is herd immunity important in the context of highly contagious diseases like measles?

It allows the disease to spread more easily.

It protects those who are not immune.

It reduces the need for vaccination.

It increases the mutation rate of the virus.

None

What is the primary difference between chronic and acute diseases?

Chronic diseases are always fatal, while acute diseases are not.

Acute diseases develop slowly, while chronic diseases develop rapidly.

Chronic diseases last for a long time, while acute diseases have a rapid onset and short duration.

Acute diseases are non-communicable, while chronic diseases are communicable.

None

Which of the following strategies is most effective in controlling the spread of vector-borne diseases?

Increasing vaccination rates

Promoting handwashing

Using insecticides and eliminating breeding sites

Ensuring clean drinking water

None

How do memory cells function in the immune system?

They produce antibodies during the first exposure to a pathogen.

They retain information about past infections and respond quickly upon re-exposure.

They act as the first line of defence against all pathogens.

They engulf and digest pathogens directly.

None

What is the underlying cause of autoimmune diseases?

Infection by a specific pathogen

Deficiency of vitamins

Immune system attacking the body's own cells

Lack of exercise

None

How does a deficiency in vitamin A affect the body?

It causes scurvy.

It leads to rickets.

It impairs vision and immune function.

It results in anaemia.

None

10.

How do airborne diseases primarily spread?

Through direct contact with skin

Through contaminated food and water

Through droplets in the air from coughing or sneezing

Through insect bites

None

11.

What role do adjuvants play in vaccines?

They kill the pathogen.

They suppress the immune response.

They enhance the body's immune response to the vaccine.

They cause allergic reactions.

None

12.

Why is it important to identify the index case in an outbreak?

To blame the individual for spreading the disease

To understand the origin and track the spread of the disease

To increase the spread of the disease

To promote panic among the population

None

13.

How does chronic inflammation contribute to disease development?

By preventing infections

By damaging tissues and organs over time

By boosting the immune response

By improving overall health

None

14.

Which of the following measures is most effective in controlling a disease outbreak?

Ignoring the symptoms

Delaying medical intervention

Quarantine and isolation of infected individuals

Promoting close contact among people

None

15.

Which immune system disorder is characterized by the body's inability to produce enough insulin?

Rheumatoid arthritis

Type 1 diabetes

Lupus

Multiple sclerosis

None

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Class 9 Practice Level 3 – Why do we fall ill set - 1

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