Date 5/02/2026 Lesson 8
Where our food comes from?
Find out about food
1. Where does food come from?
Ans :
Did each ingredient come from a plant (P) , an animal (A), or somewhere else?
2. Which parts of plants do we eat?
Write these names of food plants next to their pictures:
3. Foods that come from animals
a. For each food animal make a small slip of paper. Write the name of the animal on one side of the slip. On the other side write what that animal gives: "milk", egg, milk and meat etc. Now write the anmes of the animals in the correct part of these circles.
b. Which foods do these animals eat?
buffalo -- Grass, leaves, grains
goat -- Grass, leaves
chicken -- seed, worms, insect
fish -- microbes in water , water plant, small fishes
4. How crops are grown
a. Some food and other crops which are grown in my area:
Wheat, rice , sugarcane, maize, mustard, potatoes, onion, tomatoes, spinach etc.
b. How rice is grown? (learn steps in sequence)
1. Ploughing and applying manure
2. Leveling
3. Sowing seeds
4. Irrigation
5. Sprouting of seeds
6. Seedling grows
7. Transplanting seedling into flooding fields
8. Applying pesticides
9. Weeding
10. Harvesting
11.Threshing (Post Harvest)
The names of some farming (or gardening) tools and machines tools used in my area:
Is rice grown in your area? If not, In which nearby place is rice grown?
Yes, It is grown in all Haryana .
When is the rice sown?
Rice is sown ususally during monsoon season (June-July).
What do farmer do before they transplant the seedlings?
They prepare the field by flooding it with water and plowing to make the soil soft.
When is peddy harvested?
Around November- December
How long does it take from from the time the seeds are planted until the crop is harvested?
It takes about 4-6 months depending upon the variety of crop.
What happen after the peddy is harvested ?
- The peddy is threshed to separate grains
- Grains are dried and stored.
- Some are sent to mills for polishing and processing.
Who does most of the work in growing and harvesting rice, men or women?
Both man and woman contribute equally.
Which part of growing rice do you think is the hardest? Why?
Transplanting is the hardest because it require bending for long hours in waterlogging fields.
Notice picture (8) on page 77 of the Textbook. What do you think is the effect of adding pesticides? Could the pesticides also harm useful or harmless insects, birds or larger animals? Could they harm us?
Pesticide help to protect crop by killing harful pest .
They also harm useful insects like bees and butterflies which are important for pollination .
Large animals, birds or humans may be poisoned if they eat pesticide contained food.
The story of how rice is grown :
Rice farming starts with ploughing the soil and adding manure . The field is leveled to hold water seeds are sown in nursery and watered. the seed spread and grow into seedling . These are transplanted into flooded fields.
farmers apply pesticides and remove seeds.
When the plant turns golden they are harvested . The grains are separated by threshing cleaned by winnowing.
This is how rice is grown.
Are other crops in your area grown i n the same way? What are the differences?
No , other crops like wheat, maize and barley are not grown in same way as they need less water and are grown in dry fields.
These crops are directly sown in ground and are not transplanted.
Harvested rice requires more mannual work while others can be harvested with machine.
Think! Think!
Why do we need to plough the field before sowing seeds?
Ploughing the fields before sowing seeds helps to loosen the soil, making it easier for the seeds to grow roots and remove weeds.
5. Grow your own food (TB pg 80)
a. My plaan:
What crop to sow: Wheat
In which soil : Loomy seeds
How to plough the field: by using a plough
How much space between the plants: 20-25 cm
How often to water: ones every 10-15 days , depending on the weather.
What care to take to prevent any damage: Protect the crop from post by using natural pesticides.
How to make the crop grow better or faster: By adding organic manure and by proper irrigation and sufficient sunlight.
When to harvest the crop: When the wheat grain turns golden brown and hard.
Whether we need to separate the food from other parts of the plant:
Yes , by using threshing.
Whether we have to dry it,or shell it, wash it or cook it:
Dry the grain in sunlight and clean them before grinding to make flour.
Which part of the plant to throw away.
Husk ( Stalks and chaff)
What will happen to these parts:
Stalk can be used as fodder for animals and husk can be used as compact.
b Did you plant a crop or just one food plant?
I planted a crops of wheat.
Describe your experience:
I sowed wheat seeds, watered them and watched them grow when they turned golden, I harvested them and kept the grains.
It was a good experience.
6 Make your own flour (TB pg o. 80)
A picture of my grinding syones:
Will the flour fill the same number of measures as the grain, or more or less?
(Guess) Why?
No, Beause some of the grains turned into powder and dust.
After meauring I found there was :
Less flour than the grain
Is your roti clean?
Yes , my roti is clean.
Would you eat it?
Yes, I would eat it.
Are some grains easy to shape ? Which ones?
Yes, grains like wheat and rice are easy to shape.
Is it easier to make a roti out of coarse flour or fine flour?
It is easier to make roti out of fine flour because it sticks together better .
7. Pests and pesticides (TB pg 81)
a. Was your crop eaten or damaged while it was growing?
Yes, some crops were damaged while they were growing.
Other food crops or plants which we found damaged:
Wheat plants were eaten by locusts.
Rice plant were affected by snails.
Mango fruits were damaged by fruit flies.
How this damage might have been caused:
By insects like caterpillars feeding on plant.
Birds pecking on fruit etc.
b. The vegetables and fruits in which I found caterpillars or other insects:
Cabbage, tomatoes, brinjal, mangoes etc.
c. The grain, spices or other foods in which I found bugs:
Wheat grains, rice grains, Mustard grains and chillies.
d. The names of some pesticides used on crops or garden plants:
Neem oil, DDT, Malathion etc.
Do you use any pesticides in your house?
Yes, we use mosquito spray and chalk to kill ants.
Do you put any pesticides in foodgrains?
Yes, we use dried neem leaves or silica get packets to protect grains.
Could pesticides be harmful to us? Why do you think so?
Yes, pesticides could be harmful to use because:
- They can leave harmful chemical on fruits and vegetable
- They pollute the air , water and soil.
- They can kill helpful insects like bees.
Interesting Questions
1. Name one ingredient of food that comes from neither plant nor animal.
Salt
2. Put in the right order
threshing ploughing harvesting sowing miling irrigation
Ans : Ploughing --> Sowing -->irrigation -->harvesting --> threshing --> milling
3. Put in the right order:
bhindi flower cooked bhindi unripe bhindi on the plant chopped bhindi ripe bhindi sprouted bhindi plant
Ans : Sprouted bhindi plant --> bhindi flower -->unriped bhindi on the plant --> ripe bhindi --> chopped bhindi --> cooked bhindi
4. Write the name of the plant and the part of the plant , from which we get these foods
corn
coconut oil Maize plant, seed (grain)
sugar Coconut tree, fruit (nuts)
peas Sugarcane plant, stem
carrot Carrot plant, root
cauliflower Cauliflower plant, flower
5. Name some domestic and some wild animals that people eat.
Domestic Chicken, Cow, Goat, Pig etc
Wild Deer, Rabbit, Fish etc
6. Name some water plants and animals that people eat.
Water plant: Lotus stem, Seaweeds
Water animals : Fish, prawns, Crabs etc.
7. Name some foods eaten on certain festival days
Diwali - Sweets like laddoos and barfi
Christmas - Cakes
Pongal - Sweets pongal (rice and jaggary dish)
Classroom Discussion
1. Does everyone around you get enough food to eat?
No, not everyone gets enough food to eat
Why do some people not get enough food?
Some people are poor and cannot afford food.
Natural disasters destroys crop.
What could they do about it?
People could store food with the needed ones.
Government programs can help provide food to the poor.
Educated farmers about better farming technique.
2. Do you think sometimes people eat too much food or the wrong kinds of food? Give examples and tell why you think this happens.
Yes, people sometimes eat too much food or unhealthy food . Example - eating chips, burger or seets etc. This happens because junk food taste good and is addective . Moreover, some people donot know what is healthy.
3. What are the advantages and disadvantages of using tractors or animals for ploughing?
Tractor :
Advantages : Fact and can plough large area quickly.
Diadvantages : Expensive and uses fuel that harms the envirenment.
Animals:
Advantages : Eco friendly and good for small farms.
Diadvantages : Slower and need feeding and care.
What`s the same ? What`s different?
1. What is the difference between a fruit and a vegetable? Can a fruit be a vegetable? Give some examples.
Fruit : A fruit is a part of a plant that has seeds . e.g. Apple , Orange etc.
Vegetable : A vegetable is an edible part of a plant like root, stem. For eg - carrot, spinach etc.
Yes, some fruits like tomatoes and cucumber are used as vegetable in cooking.
2. Give two similarities and two differences between:
a. A raw Mango and a ripe one (write name of any fruit)
A raw Mango and a ripe one are similar because
(i) Both are from the same tree.
(ii) Both are edible and rich in vitamins.
A raw mango and a ripe one are different because
(i) A raw mango is sour , while ripe mango is sweet .
(ii) Raw mango is green, while ripe mango is yellow or orange.
b. A raw Carrot and a cooked one (write name of any vegetable)
A raw Carrot and a cooked one are similar because
(i) Both are from same plant.
(ii) Both are hea;thy to eat
A raw Carrot and a cooked one are different because
(i) Raw carrot is crunchy, cooked carrot is soft.
(ii) Raw carrot has more nutrients, cooked may lose some.
3. People eat only some kinds of plants and animals. Make a list of 5 plants and 5 animals that you think no one eats . For each one, tell why you think people do not eat it.
Talk and write
1. Find out about festivals, songs and dances celebrating sowing, harvesting, or other farming activites .
2. Something I ate today - Imagine and tell a story about where food came from.
I ate rice and dal .
Rice - It come from paddy fields, harvested by farmers, sent to mall and then sold in market.
Dal - It come from lentil plant, dried and cleaned before cooking with spices.
3. Ask your friend to think of some food . Ask questions to help you guess the name of that food. Your friend can only answer "yes" or "no" . How many questions did you have to ask before you could guess the answer?
Play with words
1. Play this game with your friends. The first player says the first letter of any food word. The second player says the next letter so that the word can still be completed into a food word. (It does not matter if this word is different from what the first player had in mind.) A player who cannot think of the next letter gets out. One who completes a food word gets a point.
Ask anḍ Find out (Do It yourself)
1. What is weed? What is meant by weeding?
2. What is manure ? How is it made and used? What is a chemical fertiliser? Find out the names of some fertilisers.
3. Can fertilisers and pesticides be harmful to us? In what ways?
When fertilisers and pesticides are washed off by rain where will they go?
4. Are there pesticides which are not harmful to us? Find out about safe ways of protecting grains from pests, like using neem leaves.
Figure it out
1. Suppose a family of four cooks 250 grams of rice every day. How much rice will they use in 30 days? (Remember, 1000 grams make 1 kilogram.)
Ans : 250g x 30 days = 7500 g = 7.5 kg
Where does your family get rice?
From the market or a grocery shop.
How much rice does your household use in one month?
About 3 to 5 Kg.
2. A square meter is a piece of land 1 meter long and 1 metre wide. If you can grow 5 kg of rice on each square metre of land, how many square metres will it take to feed your family for one year?
How much rice we use in one month 10 kg
How much rice we use in one year 10 x 12 = 120 kg
To grow 5 kg of rice we need 1 square metre of land.
To grow 12 kg of rice we need 120/5 =24 square metres of land
Show and tell
1. Bring some food that you carry on a long journey. Now tell the name of some foods that you would not carry on a long journey . Tell the class why.
What I brought :
I would not carry milk or curry because they might spoil quickly without proper storage. I bought dry fruits, biscuits or packed snacks.
Ask a question
Ask questions about where our foods come from. Think of how you will try to find the answers.
Q. A farmer uses different tools for sowing and harvesting crops. How do these tools, make the work easier and faster?
Ans : Plough - loosen the soil for planting .
Seed drill - plant seed quickly.
Harvests - Collect crop faster than by hand.
Date 12/02/2026
Chapter 9 Food in our bodies
Eat your lunch
1. What happens to the food we eat? (Textbook pages 86-88)
Look at the pictures on pages 86- 87 of your Textbook. They show how food travels along the digestive path and what happens to it along the way.
Write down the names of the organs in the order in which the food passes through them.
Ans :
1. Mouth
2. Food Pipe
3. Stomach
4. Small Intestine
5. Large Intestine
6. Ractum
7.Anus
2. Write numbes from 1-7 next to these sentences to put them in the correct order:
6 Water is removed from the remaining food in this larger Intestine.
2 Your teeth tear, chop and grind the food.
4 Food reaches the stomach, it is mixed with digestive juices and churned.
7 The waste food is thrown out.
1 You take a bite of food.
5 The food is mixed with more digestive juices in this long, narrow intestine. The food breaks down further.
3 The crushed food travels down the food pipe.
2. Digestive juices break down (TB p. 88)
a. What I chewed for 2-3 minutes (bread, roti made from any cereal, or cooked potato)
Bread
Describe the change in taste
After chewing , the food starts tasting slightly sweet because the saliva in our mouth breaks down starch into sugar.
Flour and potato contain a lot of starch. Saliva changes starch into sugar.
Saliva contains an enzyme called amylase that break down starch into maltose.
b.We tested these food for starch Potato, Flour, Rice, Bread
My first guess: Which ones contain starch ?
Flour and potato contain starch (Rice and Bread may be).
When we put a drop of iodine solution , these foods turned black/blue
flour/potato/Rice/Bread
These foods turned black/blue only when we crushed them and then put iodine solution.
Potato turned blue / black after crushing . Black turned blue/black after crushing.
After doing the iodine test, I think that these foods contain starch:
Flour/ Potato/ Rice/ Bread.
c. Colour of the raw potato solution no.1 when iodine solution was added to it.
Blue and Black (indicate starch is present).
Colour of the raw potato solution no.2 when iodine was added to it after it was rolled around in the mouth for 5-6 minutes.
No colour change (indicating starch was broken down into sugar saliva).
I think that the colour of the two solutions (was) /(was not) different because
The first solution contained starch, so it turned blue / black
The second solution was mixed with saliva which digested the starch into sugar , so it didn`t reach with iodine.
3. How food goes through the digestive path
a. We made the model food pipe using these things
Plastic bag (20 cm wide 4 cm long) stapter or niddle and thread (to make a tube).
Squarched banana (to act like chew food).
What I found out from the model
Food moves through the food pipe with the help of muscle contraction (squeezing and relaxing). The contraction are called pesticides which push food down the pipe.
The food pipe is similar to the small and large intestine because
All these are long, hollow tube.
The food pipe is different from the small and large intestines because
The food pipe does not absorb nutrients, but the intestine does.
The food pipe is shorter and straight, while the intestine are long and coiled.
b. We made the model stomach using these things
Clear plastic bag, water, squashed bananas, leftover food and hand.
What happens in your real stomach that is not happening in your stomach?
Digestive juices and acids break down food.
HCl kills germs
Enzyme digestive food
c. What does your model of the intestines show about what happens in the small and the large intestines?
Small intestine: Food is squeezed, nutrients are absorbed.
Large intestine: Water is removed and waste forms stools.
What things happen in the small and large intestines that this model does not show?
The model does not show chemical digestion and nutrients absorption.
d. What I heard when I put my ear on my partner`s belly (before and after a meal)?
Before a meal - very few sound or no sound.
After a meal - gurgling sound or movement sound.
I think that these sounds might be made by
Food and liquid moving through the intestine.
Muscle squeezing the food to help digestion.
4. How long is the digestive path ?
The total lenght of the digestive path is about 7 m and 68 cm.
Think! Think!
Every organ in the digestive path has a different shape. The food pipe is a short tube, the stomach is bag-shaped, while the intestines are long, coiled tubes, What would happen
a. If the food pipe was coiled?
Food would get stuck and not more easily.
b. If the stomach was a straight tube?
Food would not be churned or mixed properly.
c. If the intestines were short and straight?
Food would not be fully digested.
Nutrients and water would not be absorbed properly.
5. How food changes inside the body
a. Where have you seen partly digested food?
Partly digested food is seen when someone vomite.
Describe how it looked and what kind of taste it left in your mouth.
Partly digested food looks soft and watery. It tastes sour and bitter.
b. What is the colour of your stools?
Usually brown in colour.
Does this colour change from day to day?
Yes(depending upon the food eaten).
Describe the colour of your stools on the day after you have eaten green leafy vegetables, beetroot or a lot of tomato.
Greeen vegetables - green stool
Beetroot - red stool
Tomatoes - orange and reddish
Think! Think!
People sometimes say that if you swallow a seed, "a tree will grow in your stomach and its branches will come out of your ears!" Is this possible? Why or why not?
No, it is not possible because seed need soil, water and sunlight to grow which are not present in the stomach. Therefore seed cannot grow in stomach.
6. Other animals have to digest food too!
Look these pictures of digestive paths of the earthworm, bird and mouse. Draw arrows in them to show the path of the food.
Pharynx: Suck food inside
Crop: Stores the food
Gizzard - food is ground with the help od tiny stones mixed in it.
Intestine - food is digested and absorbed
Anus - food waste are thrown out.
Which of these animals have a mouth and an anus ? Earthworm, Bird, Rat
Which of them have a stomach? Rat, Bird
The food canal of which animal looks most like our own? Mouse
Exercises
Act it out
1. Act out digestive. One student each could play the role of an organ like, the mouth, teeth, food pipe, stomach, small intestine, large intestine and anus. A round piece of paper could be the roti. Pass the roti along this digestive system. Act out what happens to it.
Interesting Question
1. In the picture on the opposite page, fill in the missing parts and add the missing labels.
Classroom discussion
1. In what ways does food change inside our body?
Food is broken into smaller pieces. It become soft .
2. Suppose food remained as it was. Could it be used be the body? No.
Why or why not?
No, the body cannot use undigested food. Food must be broken down to give energy, nutrients are absorbed for energy.
2. Suppose you put some mashed up food in a bowl, added some of the digestive juices produced inside our body and mixed it well. Would the food in the bowl get digested? Why or why not?
No, food in a bowl will not get digested. Digestion needs movement and body heat.
3. Does digestion occur while we are asleep? Why do you think so?
Yes, Digestion happen during sleep.
The stomach keeps working to break down food.
4. What will happen if we eat more food than we need? Will we get extra energy or become very strong?
Eating too much food can lead to fat storage in the body and may cause weight gain instead of strength and energy .
5. Have you had indigestion? Yes.
What might have gone wrong with your digestion then?
It may be due to eat to much or too fast.
Have you even noticed any gas coming from your stomach or intestines? Yes
How could gas get into the digestive path? It happens when we swallow air or when food breaks down in the intestine.
What`s the same? What`s different?
1. Is our digestive system similar to a kitchen grinder? How?
Yes, it is similar because both break food into smaller pieces.
How is it different? What things happen to the food in the digestive system but not in the grinder?
The digestive system uses juices and enzymes, to breakdown food. It absorbs nutrients into the blood, but a grinder cannot do this.
Figure it out
1. Mini and her friend Kairi ate a delicious mango at 3 pm on Monday. The graph shows how long it took them to digest the mongo.
Look at the graph and answer these question:
a. Where was the mango at 4 pm, Monday in Mini`s digestive path? Stomach
b. Where was the mango`s at 4 pm, Monday in Kairi`s digestive path? stomach
c. Where was the mango`s at 10 pm, Monday in Mini`s digestive path? Large intestine
d. Where was the mango`s at 10 pm, Monday in Kairi`s digestive path? Small intestine
e. Did Mini and Kairi take the same amount of time to digest the mango? No
f. How many hours did it take each of the girls to digest the mango? Mini - 39 hr. and Kaira - 50 hr
Chapter 10
What is thrown out?
Where our food goes
1. The parts we throw away (TextBook page 96)
a. Fill this Table for some plants you choose from the pictures on pages 119 - 121 :
b. Fill in this table to show which parts of the rice plant are thrown away at each stage:
Are any of these parts useful? How?
Leaves and stems → used as fodder for animals or compost to improve soil fertility.
Husk and chaff → used as animal feed and for making mats.
c. Fill this table for some animals whose flesh we eat:
d. My estimate of how much garbage is produced in our kitchen in one day:
1 kg of waste
Where does all this garbage go?It goes to a garbage dump or recyclinmg centre.
Think! Think!
In preparing food from plants and animals, we throw large parts into the garbage. Could these parts be useful in any way?Make your own guesses.
Plant parts like pea / seeds and stem can be composted to make soil.
Animal parts like bones can be used to make fertilizers.
Leftover food can be feed to animal.
2. Who eats our wasted food? (TB 0g 96-97)
Name some animals who eat the food that we thrown away.
Dogs, cats,cows, crows and pigs etc.
Write in your own words what happened to the banana peels in the pictures on pages 96-97 in your Textbook.
The banana peel started to decompose.
Microbes broke them down, turning them into compost.
3. How microbes decompose food (TB pg 97-100)
a. Contents of your plate
Food items like cooked fruits and vegetables etc.
Where it was kept
Covered plate - kept inside a closed container
Observations : Uncovered plate kept outside in the open.
Describe what happened to the food in the other plates.
The uncovered food started rotting and smelled bad.
Describe the mould that you saw.
The mould was a white or greenish growth on the food, caused by microbes breaking down the food
.
Guess how this food might look after several months.
The food might turn into dry, crumbly bites or turns into dark composed matter (soil).
b. Describe the smell of a garbage bin.
It smells bad and sour due to decaying food and waste.
Did the garbage smell like this before you put it into the bin?
No.
What makes it smell now?
It smells now because food is rotting and Decomposing inside the bin.
If you do not brush your teeth does your mouth smell? Guess why.
Yes, our mouth smells because food particles and germs stay in our mouth and starts to decomposed.
What will you find under the soil when the peels have decomposed completely?
We will find soft, dark and crumbly soil that is richer in nutrients.
Guess how many days it will take for the peels to mix into the soil and the air.
It may take 10-20 days.
At 2pm Mini found little bubbles in the dal. Where did the bubbles come from?
The bubbles come from the action of microbes like bacteria.
What might have happened if Mini ate the dal?
Mini might have gotten sick from the germs in the dal.
What should Apu have done first after he came back home from playing?
Apu should have washed his hands first to remove dirt and germs.
Was there a better way of checking whether the dal was warm or cold?
Apu could have touched the dal with a clean spoon to check if it was warm.
Think! Think!
I don't like microbes! Apu said. "They are dirty and smelly! They make us sick. Microbes are not dirty! Mini replied. They make everything clean. They eat garbage and break it down into smaller and smaller pieces that go back into the soil and help plants to grow!
What do you think?
Microbes are helpful because they break down waste and help plants grow. Not all microbes make us sick. Some are good and help keep things clean.
What could we do with our food garbage.
We could compost food garbage, turning it into compost that help plants grow.
5. Microbes in our faces (TB p. 100)
Why do you need to wash your hands well after you go to the toilet?
Washing hands after using the toilet is important to remove harmful microbes that can cause sickness.
Why should faeces never come into contact with food or drinking water?
Faeces contain harmful germs that can make you sick if they touch food or water.
Think! Think!
Have you ever noticed gas in your intestines? Where could this gas have come from?
From the food we eat.
6. Where does our waste ho?
a. Describe the place where you defecated:
The place is a toilet.
Where do you think your wastes go?
The waste goes into a septic tank or sewage system, where they are broken down or treated.
b. Which of the pictures in the Textbook best shows the kind of latrine that you use?
Picture VI
What happens to the urine and the faeces?
Urine and faeces are either collected in a septic tank or drained into a sewage system for treatment.
Is any part of the waste carried away from the place of defecation?
Yes, the waste is carried away through pipes or drains .
How much water might be needed for each use?
Around 2-3 litres.
Would you expects to find files and dirty smells afterwards?
Yes.
i. Outdoor defecation
Take care!
Do not defecation near a pond, stream or well! (Why not?)
Defecating near pond etc can pollute the water and make it unsafe for drinking.
Do not defecate close to where people live! (Why not?)
Decating near homes can spread diseases and make the area unhygenic.
Why should you cover the faeces with soil?
Covering faeces with soil helps to keep the area clean and prevents separating diseases.
Think! Think!
If only a few people defecate outdoors, there is no need to carry away the waste. What would happen if many people defecate outdoors every day around the same place?
If many people defecate in the same place, the area would become very dirty and spread diseases.
ii. Service latrine
What could be done with the waste in a service latrine?
The waste can be collected , treated and safety disposed off or used for composing.
Is the work of carrying waste dangerous ? Why ? Think of how it might be done in a safer way.
Yes, It is dangerous because it can spread germs. It should be done with protective gear and safety transported to treatment plant.
iiii. Pit latrine
What happens to waste in the pit latrine?
The waste collects in a deep hole and slowly decomposes.
iv. Septic Tank
How is the liquid waste carried away from the septic tank?
It flows through pipes into a drain field .
Where do you think it goes?
It goes into the soil and is absorbed or filtered naturally.
What would happen if sewers from many such latrines emptied into a river or lake?
The water would get polluted and unsafe for drinking or bathing. It can harm fish and other animals.
v. Flush toilet
The solid and liquid waste from many flush toilets usually goes into large sewers. Big cities have lakhs of people staying in them. What could we do with all their waste?
The waste can be treated in sewage treatment plant to clean it before releasing it into rivers or using it as a fertilizers.
7. Microbes help to decompose our waste!
Is there a sewage treatment plant in your locality?
Yes.
What did you find out about it?
It cleans the waste and removes harmful substances before releasing into water.
Does the sewage pose any danger to humans and other living things in your locality?
Yes, if untreated sewage leaks or is not cleaned properly, it can cause diseases and harm plants and animals.
Think! Think!
What would happen if your faeces did not decompose?
It would keep collecting , create a bad smell and spread diseases.
Know these words
Ditches and pipes which carry waste water are called Sewers.
Waste carried be sewers is called sewage.
Interesting questions
1. If liquid food like a curry is left around it starts smelling bad and you might see bubbles in it . Remember what you know about microbes to explain this.
Because microbes grow in it . They break down the food and produce gases that cause bubbles and bad smell.
2. Name so,e foods that spoil (decompose) quickly and some others that last for a longer time.
Food that spoil quickly - Milk , fruits, vegetables etc.
Food that last longern- Dry fruits, honey, sugar etc.
3. If you keep flour open it spoils. If it is covered in a box it lasts for a longer time without spoiling . Why?
If you keep flour open, it spoils because moisture and microbes can get in . In a covered bar , it stays dry and safe from microbes.
4. If you keep milk very cold it lasts for a longer time without spoiling . Why?
Milk lasts longer when it is very cold because cold temperature slow down the growth of microbes.
5. If you dry some foods in the sun , they keep for months or years without spoiling . Why?
Drying food in the sun removes water so microbes cannot grow, keeping the food safe for months and years.
6. Name some ways of making food last for a longer time without spoiling . Find examples of cereals, pulses, fruits, vegetables, fish and meat which are preserved in different ways.
* Drying - eg fruits, vegetables etc.
* Pickling - eg mangoes, lemons etc.
* Salting - eg Meat and fish etc.
7. Which do you think will decompose faster:
a. bread or wood ?
Bread will decompose faster than wood.
b. dry bread or moist bread?
Moist bread will decompose faster than dry bread.
c. bread in a warm place or in a cold place?
Bread in a worm place will decompose faster.
d. a banana peel thrown away during the monsoon , or during a dry season?
Banana peel in the monsoon will decompose faster than during a dry season .
Classroom discusssion
1. Apart from food wastes, what other things are thrown out in your garbage?
Plastic bag, papers, glass, bottle, broken toys , old clothes and food wrappers.
Are there things in your garbage that microbes might not decompose? What could we do with these things?
Yes, plastic , glasss and metals cannot decompose. We can recycle or reuse them.
2. Why is it dangerous to keep garbage lying around?
It can be collected stored and sent for recycling composting or land filling.
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