NCERT Solutions for Class 5 EVS Our Wondrous World Chapter 3 The Mystery of Food

Page 42

Think

Have you ever had an upset stomach? Do you know what could have caused it? What could happen if spoiled food is eaten by mistake? If yes, what did you do to get well? Share
your experiences with the class.
See AnswerYes, once I had an upset stomach after eating golgappas from a street stall near the Rajdhani Park. I think the water they used was not clean and maybe the puris were not fresh. My stomach started hurting in the evening and I felt like vomiting. Amma said it might be because of germs in the food. If we eat spoiled food by mistake, it can make us sick, give us diarrhoea or cause vomiting. Amma made me drink lots of boiled water and gave me curd with a little sugar. She said curd has good microbes that help the stomach. After resting for a day, I felt much better.

Write

Why do you think food gets spoiled?
See AnswerI think food gets spoiled because tiny living things called microbes grow on it. These microbes need moisture, air, and the right temperature to grow. When they grow, they change the taste, smell, and look of the food, and it becomes unsafe to eat.

Page 44

Write

What other things are dried so that they remain unspoilt throughout the year?
See AnswerOther things that are dried so they remain unspoilt throughout the year are papad, aam papad, fish and herbs like coriander or mint leaves.

Activity 1

What items can be made from mangoes to enjoy them for longer durations? Write their names in the space given below.
See AnswerItems that can be made from mangoes to enjoy them for longer durations are:
► Aam Papad
► Mango Pickle
► Mango Jam
► Mango Juice
► Mango Shake
► Mango Chutney

Page 45

Activity 2

1. Take a tomato and cut it into slices.
2. Put the slices of tomatoes on a tray and place it on the window where the sunlight comes through.
3. What changes did you observe in the fruit?
Can you think of a way to preserve items like tomato?
See AnswerAfter some time in the sunlight, the tomato slices will start to lose water, become smaller and shrink. Their skin will wrinkle and they will feel dry instead of soft and juicy.
A way to preserve items like tomato is to dry them completely in the sun to make dried tomatoes or to make tomato pickle, tomato sauce or store them in airtight bottles after cooking.

Discuss

What would happen to this pickle if no oil had been added?
See AnswerOil acts like a protective layer on pickle. It blocks air from reaching the food and since microbes need air and moisture to grow, they cannot survive. Without oil, air reaches the pickle, microbes start multiplying and the pickle spoils, changing its taste, smell and colour, making it harmful to eat.

Page 46

Activity 3

Find out about food preservation practices at your family by asking the elders at home. Write at least one such practice.
See AnswerIn my family, Amma dries neem leaves and keeps them with stored grains like rice and wheat. The smell of neem keeps away insects and pests, so the grains stay fresh for many months.
My Chachi makes lemon pickle by adding salt and keeping it in sunlight for many days. The salt and sunlight together stop microbes from growing, so the pickle stays good for a long time.

Page 48

Think

Did you ever have an upset stomach, vomiting or indigestion? Did you use any home remedies? Write about the home remedy given to you.
See AnswerYes, once I had an upset stomach after eating ice gola from a fair. Amma gave me buttermilk with a little roasted cumin powder and salt. She said it cools the stomach and helps in digestion.

Page 49

Activity 4

Do you ever accompany your elders for buying vegetables and fruits? During such visits, observe how elders select fruits and vegetables in the market.
Write one thing that you learnt from your shopping trip and write it as a Finding #9, the way Disha would write.
See AnswerWhile buying vegetables, Amma gently pressed tomatoes to check if they were firm but not too hard. She said this shows they are fresh and ripe, perfect for cooking.

Page 50

Write

Name three seasonal fruits or vegetables of your region.
For example, amla in winter and jamun in summer.
See AnswerI live in Rajdhani Park, Delhi.
The three seasonal fruits and vegetables of my region:
• Mango in Summar
• Mustard Greens in Winter
• Lychee in Rainy

Activity 5

When you eat, try chewing each item properly till it breaks down into smaller pieces and then into mush. Which teeth did you use to cut and chew? Look at the diagram given on the next page and name them.
See Answer► To cut the food, I used my incisors.
► To tear the food, I used my canines.
► To crush and grind the food into mush, I used my premolars and molars.

Page 53

Write

How can you avoid choking?
See AnswerWe can avoid choking by taking small bites, chewing food properly, eating slowly and not talking or laughing while food is in the mouth.

Let us reflect

1. Why do some food items last for weeks and others spoil in just a few days?
See Answer1. Some food items last for weeks because they are preserved by methods like drying, oiling or refrigeration, which stop microbes from growing. Others spoil in a few days because moisture, air and temperature help microbes grow.

2. You are going on a field trip for two days. List five food items you will carry. How will you keep them from getting spoiled?
See AnswerOn a two-day field trip, I will carry:
• Mango Pickle
• Paratha
• Dry Fruits
• Puffed Rice
• Snacks
I will keep them in airtight containers or packets to stop air and moisture from reaching them.

3. What if food cannot be preserved? Imagine a world without food preservation and discuss the consequences.
See AnswerIf food cannot be preserved, it will spoil quickly, causing a shortage of safe food. People will have to eat only freshly cooked items, wasting a lot of food. There will be more hunger, higher prices and difficulty in storing food for emergencies or sharing it between places.

4. Match the following.
Which method is used to preserve the following food items (A) to make the final product (B).

Answer:

Practice Questions for Exam Preparation in Class 5 EVS Our Wondrous World Chapter 3 The Mystery of Food

What are tiny living things that spoil food called?
See AnswerMicrobes

Which instrument is used to see microbes?
See AnswerMicroscope

Name one good microbe found in curd.
See AnswerLactobacillus

Which three things do microbes need to grow?
See AnswerMoisture, air and suitable temperature

What is removed from chillies when they are dried?
See AnswerMoisture

Which ingredient is added to pickles to block air?
See AnswerOil

Where are milk, butter and vegetables stored to slow microbial growth?
See AnswerRefrigerator

Which natural ingredient is used with grains to keep insects away?
See AnswerNeem leaves

Name one spice used in food preservation.
See AnswerBlack pepper

Which seasonal fruit did Disha’s father bring during the rainy season?
See AnswerLychee

Which teeth are used to cut food?
See AnswerIncisors

What should you do after eating to keep teeth clean?
See AnswerRinse our mouth

What can happen if you eat spoiled food?
See AnswerUpset stomach

Which bacteria make idli batter rise?
See AnswerFermentation microbes (like yeast and bacteria)

What is the first step in making ghee from butter?
See AnswerHeat the butter

What causes food to spoil?
See AnswerFood spoils when microbes grow on it. They need moisture, air and a suitable temperature to grow. These microbes change the taste, smell and look of food, making it unsafe to eat.

How does drying preserve food?
See AnswerDrying removes moisture from food. Without moisture, microbes cannot grow, which helps the food stay fresh for longer. Examples include drying chillies, papads and mango slices.

Why is oil used in pickles?
See AnswerOil creates a protective layer that prevents air from reaching the pickle. Without air, microbes cannot grow, so the pickle stays unspoiled for a longer time.

How does refrigeration help in food preservation?
See AnswerRefrigeration lowers the temperature, which slows down the growth of microbes. This keeps perishable food like milk, vegetables and cooked items fresh for a few days.

What are the benefits of eating seasonal fruits?
See AnswerSeasonal fruits are fresher, tastier and more nutritious. They are harvested at the right time, travel less distance and do not need artificial preservation.

Why is chewing food properly important?
See AnswerChewing breaks food into smaller pieces, mixes it with saliva, and makes digestion easier. It also prevents choking by ensuring food is soft before swallowing.

What is oral hygiene?
See AnswerOral hygiene means keeping the mouth and teeth clean by brushing, rinsing after meals, eating fewer sweets and visiting the dentist when needed.

Name two traditional methods of food preservation.
See AnswerDrying in the sun and salting are two traditional methods that prevent microbial growth and keep food safe for a long time.

What are good microbes? Give one example.
See AnswerGood microbes help in food preparation or digestion. For example, Lactobacillus in curd aids digestion and makes curd thick and tasty.

How does canning preserve food?
See AnswerIn canning, food is stored in airtight containers. This prevents air from entering, keeping microbes away and preserving the food for months.

List different food preservation methods.
See AnswerDifferent food preservation methods:
• Drying in the sun
• Adding oil to pickles
• Refrigeration and freezing
• Salting and sugaring
• Airtight canning and packaging
• Using spices like pepper
• Storing with neem leaves

What are the harmful effects of eating spoiled food?
See AnswerThe harmful effects of eating spoiled food:
• Upset stomach
• Vomiting
• Diarrhoea
• Loss of appetite
• Weakness or dehydration
• Need for medical treatment in severe cases

Write the uses of different types of teeth.
See AnswerUses of different types of teeth:
• Incisors: Cutting food
• Canines: Tearing food
• Premolars: Crushing food
• Molars: Grinding food

Give examples of traditional food preservation in Indian homes.
See AnswerExamples of traditional food preservation in Indian homes:
• Drying chillies for chilli powder
• Making aam papad from mango pulp
• Pickling lemons with oil and spices
• Storing grains with neem leaves
• Making papads by drying dough in the sun

Write the main “Findings” from Detective Disha’s notebook.
See AnswerThe main “Findings” from Detective Disha’s notebook:
• Microbes are found everywhere
• Removing air or water stops microbial growth
• Drying prevents spoilage
• Oil blocks air in pickles
• Cold slows microbes
• Many ways of preserving food exist
• Good microbes help in food preparation
• Bad eating habits cause indigestion

Notes to revise the complete chapter 3 before exams.

Introduction to the Mystery of Food
In Class 5 EVS Our Wondrous World Chapter 3, we enter the world of Detective Disha, a curious young girl who sets out to solve the mystery of why her favourite uttapam spoiled after being left in her lunchbox for three days. Through her questions and discoveries, we learn that food spoilage happens because of tiny living organisms called microbes. These microbes are everywhere—in the air, water, soil and even inside our bodies. Some microbes are harmful and make food unsafe, while others are helpful and aid in making food like curd and idli. The chapter immediately captures students’ interest by connecting science to everyday experiences, encouraging them to think critically about the food they eat and how it is stored.

How Food Spoils and How We Preserve It
Class 5 EVS Chapter 3 explains that microbes need three main things to grow—moisture, air and the right temperature. If any of these is removed, microbial growth slows down and food stays fresh longer. Detective Disha observes various preservation methods at home—drying chillies in the sun to remove moisture, adding oil to pickles to block air, storing food in refrigerators to lower temperature and using salt, sugar and spices to prevent spoilage. Class 5 Our Wondrous World Chapter 3 introduces modern preservation techniques like canning and airtight packaging used in factories. By blending traditional Indian methods with modern science, the chapter helps students understand that food preservation is both a cultural practice and a scientific process.

Healthy Eating Habits and Oral Care
The lesson does not stop at just preservation; it also focuses on healthy eating and proper digestion. It explains the importance of chewing food properly using different types of teeth—incisors to cut, canines to tear, premolars to crush and molars to grind. Chewing releases saliva, which starts digestion and prevents choking. The chapter also highlights oral hygiene, showing how cavities can develop and how regular brushing, rinsing and limiting sweets keep teeth healthy. Through these points, students learn that taking care of what we eat and how we eat it is essential for overall health, just like storing food safely.

Traditional Wisdom and Final Learning
In the final part, Disha’s “Findings” notebook is filled with important lessons—good microbes help in making certain foods, seasonal fruits taste best when eaten in their natural season and bad eating habits can cause indigestion. The chapter also celebrates traditional Indian wisdom, such as storing grains with neem leaves, making aam papad from mangoes and preserving food with natural spices. Students are encouraged to reflect on their own family’s food habits and to appreciate the connection between culture, health and sustainability. By the end, the “mystery of food” is solved—eat right, store right and thank the good microbes. This chapter successfully combines science, culture and healthy habits into one engaging and practical learning experience.