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Class 8 Science · Chapter 3 · NCERT (hecu103)

Health: The Ultimate Treasure: common misconceptions

See the tempting mistake students make in Health: The Ultimate Treasure, why it feels right at first glance, and a worked visual example that shows the right idea.

The tempting mistake & worked visual

Do antibiotics treat viral infections?

Wrong

An antibiotic kills the virus that causes a cold.

Why it feels right. A medicine for one infection seems useful for every infection.

Right

Antibiotics act on bacteria. Viral infections involve different targets.

Worked example

Example bacterial target
Bacterial cell wall→Some antibiotics block its formation
Cold virus
No bacterial cell wall→Same target is absent
The antibiotic's bacterial target is absent in a cold virus.
  1. A common cold is caused by viruses.
  2. Its virus lacks the bacterial structures that many antibiotics target.

If your child says… (8 concept checks in this chapter)

As you work through Health: The Ultimate Treasure, listen for these everyday misunderstandings and use the prompt alongside each one.

1. Health and healthy habits See how to teach this step →

If your child says… “Screens only affect my eyes.”

Ask together
If phone use keeps you awake, which need is being missed?
What’s true
Excessive screen use can affect sleep and emotional well-being even when eyes feel comfortable.
2. Surroundings and health See how to teach this step →

If your child says… “Cleaning rubbish only makes places look nicer.”

Ask together
What happens to that breeding place when the trapped water is removed?
What’s true
Clearing containers that collect water can reduce mosquito breeding.
3. Communicable and non-communicable diseases See how to teach this step →

If your child says… “Every disease comes from someone else.”

Ask together
How would avoiding people supply a missing nutrient?
What’s true
Scurvy develops from too little vitamin C, without being caught from anyone.
4. Signs and symptoms See how to teach this step →

If your child says… “A normal reading means nothing is wrong.”

Ask together
Does a normal temperature make the person's dizziness disappear?
What’s true
Someone's felt symptoms remain useful evidence even when measurements are normal.
5. Pathogens and routes of spread See how to teach this step →

If your child says… “The mosquito itself causes malaria.”

Ask together
Which enters during the bite: the whole mosquito or the parasite it carries?
What’s true
An infected mosquito carries the parasite that causes malaria.
6. Preventing communicable diseases See how to teach this step →

If your child says… “Handwashing protects me from every infection.”

Ask together
What would keep a mosquito from biting a freshly washed arm?
What’s true
A useful precaution against one route may leave another route open.
7. Immunity and vaccination See how to teach this step →

If your child says… “Cowpox is just smallpox in cows.”

Ask together
Does recognising similarities between two viruses make them the same virus?
What’s true
Cowpox and smallpox have different, related viruses whose shared features can be recognised by defences.
8. Antibiotics and antibiotic resistance See how to teach this step →

If your child says… “Antibiotics cure every infection.”

Ask together
What can the medicine target if the virus lacks those bacterial parts?
What’s true
Antibacterial antibiotics cannot treat flu because its virus lacks the bacterial targets they act on.

Use this chapter three ways