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NCERT Solutions for Class 5th The World Around Us Chapter 3 Food Spoilage — Mystery #1

Book page 41 Updated on2026-09-19

Q1.
Mystery #1: What made my uttapam spoil?
Answer

Tiny living things called microbes grew on the uttapam and spoiled it. The coloured patches Disha saw were mould. Mould is not one creature — it is a colony, that is a large crowd, of thousands of microbes living together. We can see the patch even though we cannot see one microbe.

Here is what happened inside the closed tiffin box, step by step.

  1. The uttapam was soft and moist. Moisture means the water in a food.
  2. The box was shut, but there was still air inside it.
  3. The box lay in a warm room for three days — Friday, Saturday and Sunday.
  4. Moisture, air and warmth are exactly the three things microbes need. So the few microbes already on the food began to grow and multiply.
  5. By Monday there were so many of them that they showed up as coloured patches, and the food had begun to smell foul.
What Disha noticedWhat it really was
A foul smell when she opened the boxMicrobes had broken down the food and made new smelly substances
Coloured patches on the uttapamMould — a colony of thousands of microbes
The food no longer looked or felt like fresh uttapamThe microbes had changed its colour, taste and texture
Why it happens: Microbes are alive, so they must eat. Our food is their food too. As they eat it, they change it — that is why the taste and the smell change. Warm, moist food that is left standing gives them the perfect place to grow.
Important: Food with mould on it must never be eaten, even after scraping the patch off. Throw it away, wash the box with soap and hot water, and dry it well.
Q2.
Disha enquired, “Microbes? Are they like little lice?”.
Answer

No. Microbes are much, much smaller than lice. You can see a louse with your own eyes. You cannot see a single microbe at all — you need an instrument called a microscope, which makes very tiny things look big.

A louseA microbe
Can you see one?Yes, with your eyesNo — only through a microscope
Where does it live?On hair and skinEverywhere — soil, water, air, plants, animals, and inside us
What does it do?It bites and itchesSome spoil food; some help us make curd and idli, and help us digest food

Finding #1 in Disha's notebook: Microbes are found in soil, water, the air around us; in plants, animals, and inside us!

Why we see mould but not microbes: One microbe is far too small for our eyes. But when millions of them grow together in one spot, the crowd becomes big enough to see — and that crowd is the coloured patch we call mould.
Not all microbes are harmful. The very same family of tiny living things gives us curd, buttermilk, idli, dosa and bread. Some live inside our stomach and help us digest our food. Only some kinds spoil food or make us ill.
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