Showing posts with label CBSE-EVS-CLASS V. Show all posts
Showing posts with label CBSE-EVS-CLASS V. Show all posts

Saturday, March 5, 2016



Children in these lesson we are going to learn about seed germination and dispersal of seeds.

Gopal was waiting for his mausi’s family to visit them. They will be coming the next day for their holidays. He was thinking about all the fun and nice food that he would have with his cousins.

Just then his mother called out, “Gopal, before you sleep, remember to soak two small bowls (katoris) of chana (gram).” She was going to his Bua’s house and would return only in the morning.

As he was soaking the chana, Gopal thought, “How will two small bowls of this be enough for eight persons?” So he soaked another two bowls of chana.

When his mother returned the next morning, she saw that the chana were overflowing from the vessel. “How much did you soak?” asked his mother. “How did that happen!” wondered Gopal.

“You soaked too much! Anyway it is good, now I will cook half of them, and leave the other half to sprout. I can send these to your aunt. The doctor has told her to eat sprouts”, mother said. She tied half of the soaked chana in a wet cloth, and hung them up to sprout.

Let us see about seed germination:
Growing plants from seeds:
Children if u eat an apple or an orange you will fine deeds inside. New plants can grow from these seeds.

Not all seeds grow into new plants . some seeds are eaten up by birds and insects. Some seeds get destroyed by the rain or wind. If seeds get sufficient amount of air, water, warmth it grows in to new plant .

 A seed producing a new bady plant  or seedling . this process we called as seed germination.

During the early stages of germination , the sedling gets the foods which ift requires for its growth from the cotyledous. The food which stored in cotyledous has been used up the seedling gets its food from the soil.

The seddlings absorbs water and nutrients from the soil with the help of its roots. The it develops new leaves and grows in to a new abay plant.

Now it requires air for seed germination. The air reaches the seed through pores in the soil. That is why soil is so important for plants growth.

Afte they germinate, they will struggle for air, water, light, nutrients and the space to grow. As a result, many of them would die.

Structure of seed:
Children have you seen a bean or a gram seed. It is hard and cannot be broken easily. The hard outer covering layer is alled the seed coat. The seed coat protects the sed.

 The seed has two cotyledons. These are special seed leaves which protect baby plant or embryo. They also store food for the embryo.
Seeds like grmas, beans and peas have two cotyledons while seeds like wheat and corn have only one cotyledon.

Let us see about seed dispersal:
Seed Dispersal: The process by which seeds are scattered away from the mother  plant is called dispersal.

Seed Dispersal By Water: some plants of seeds like lotus and coconut are spongy in nature or they have a fibrous covering, on they outer surface. This help them to float on water easily. Water carries these seeds easily from one place to another. this type if dispersal is called as Seed Dispersal by water.
Example: lotus, coconut and water lilly.

Seed Dispersal By Wind: some seeds of certain plants are very light in weight and have wing-like structures or hair on them. These type of seeds can easily carried away by the wind from one place to another place. This type if dispersal is called as Seed Dispersal by wind.
Examples: Plants like cotton, dandelion and madar.

Seed Dispersal By Explosion: the fruits of some plants just like poppy, pea and bean. These fruits can burst and open when they ripe, scattering the seeds in all directions . this type if dispersal is called as Seed Dispersal by explosion.
Examples: fruits like pea and balsam.

Seed Dispersal By Animals: some plants cocklebur seeds have spine or hooks on their body. These seeds stick to the bodies of animals and birds. So they carried away from the mother plant. this type if dispersal is called as Seed Dispersal by animals.
Examples: plants like xanthium,tigernailsma and spear grass.

These are the various types of dispersal of seeds which grows in to a new baby plant.

This happened in 1948. One day George Mestral came back from a walk with his dog. He was amazed to find seeds sticking all over his clothes and on his dog’s fur. He wondered what made them stick. So he observed these seeds under a microscope. He saw that the seeds had many tiny hooks which got stuck to clothes or fur. This gave Mestral the idea of making Velcro. He made a material with similar tiny hooks that
would stick. Velcro is used to stick together many things – clothes, shoes, bags, belts and many more. What a way to take inspiration from nature!

Who came from where:
Have you included human beings also in your list? Yes, we also carry seeds from one place to another, knowingly or unknowingly. We bring the seeds of plants that we find beautiful or useful, to grow them in our garden.

Later the seeds of these plants spread to other places. Many years later people may not even remember that these plants did not grow here earlier. They were brought from somewhere else. Here some of the seeds they dispersal from one place to another

Do you know from where chillies came to our country? These were brought to India by traders coming from South America. Today we cannot think of food without chillies!

From South America long ago, came a tomato, a potato, and a green chilli. Do you know this?

A cabbage came from Europe, and also a pea. From Africa came a coffee bean, and a green bhindi.

A mango sang, ‘Come in! Come in!’ An orange smiled inside its skin. ‘Welcome to India,’ a banana said. the methi and spinach, brinjal and radish, nodded its head.

Pants from sopres:
Some plants like fren, fungi and moss do not have flowers. So, they do not not produce seeds. They produce tiny spores. This spores develops into new baby plant.

Plants grow different body parts;
Some plants grow from the body parts of the parent plant. The method of obtaining new plants from the leaves, stem and roots of the parent plant is called vegetative propagation.

Plants like potato and ginger have eyes on them. Under suitable conditions they grow in to a bud from new baby plant growa.

Onion and ginge plants also grow from their underground bulb –shaped stems.

Plants like bryophyllum, gorws from the edges of leaves buds.
Some plants grows from buds on the stem examples rose hibiscus, sugarcane etc.





Different tastes:
Taste buds are sensory organs that are found on yourTONGUE and allow you to experience tastes that are sweet, salty, sour, and bitter. How exactly do your taste buds work? Well, stick out your tongue and look in the mirror.

Taste buds contain the receptors for taste. They are located around the small structures on the upper surface of the tongue, soft palate, upper esophagus, the cheek, epiglottis, which are called papillae. The myth of the tongue map; that 1 tastes bitter, 2 tastes sour, 3 tastes salt, and 4 tastes sweet.

Jhumpa ran into the kitchen and caught hold of her mother saying, “Ma, I am not going to eat this bitter karela (bittergourd). Give me gur (jaggery) and roti.”

 Ma smiled and said, “You ate roti and sugar in the morning.” Jhoolan teased Jhumpa, “Don’t you get bored of only one kind of taste?” Jhumpa replied quickly, “Do you get bored with licking imli (tarmarind)? I bet your mouth is watering just by hearing the word imli.”

 “Sure I love the sour imli. But I eat sweet and salty things too. I even eat karela,” said Jhoolan and looked at her mother.

They both laughed heartily. Jhoolan said to Jhumpa, “Let’s play a game. You close your eyes and open your mouth. I will put something to eat in your mouth. You have to tell what it is.”

Jhoolan took a few drops of lemon juice in a spoon and put them in Jhumpa’s mouth. “Sour lemon,” Jhumpa replied quickly.

Jhoolan then picked up a small piece of jaggery. Her mother suggested, “Crush it, otherwise she will know what it is?” Jhoolan crushed the jaggery but Jhumpa easily guessed it.

They played the game with different food items. Jhumpa could tell the fried fish even before tasting it. Jhoolan said, “Now close your nose, and tell me what this is?” Jhumpa was confused, “It is a bit bitter, a little salty and somewhat sour.

Give me one more spoonful.” Jhoolan took another spoonful of the cooked karela, uncovered Jhumpa’s eyes, and said, “Here it is, eat!” Jhumpa laughed, “Yes, give me more.”

Nitu was given a glucose drip:
Nitu was very sick. All day she was vomiting and she also had loose motions. Whatever she ate, she vomited. Her father gave her sugar and salt solution. By evening Nitu was feeling weak and dizzy. When she got up to go to the doctor she fainted.

Her father had to carry her to the doctor. The doctor said that Nitu should get admitted in the hospital. She needs to be given a glucose drip. Hearing this, Nitu got confused. She knew that during the games period in school, the teacher sometimes gave them glucose to drink.

But what was a glucose drip? Doctor aunty explained, “Your stomach is
upset. Your body is not keeping any food and water and it has become very weak. The glucose drip will give you some strength quickly, even without eating.”

Story – A Stomach with a Window:
In the poem, you read about a soldier called Martin. In 1822, he was eighteen years old and was very healthy. When he was shot, he got seriously hurt. At that time Dr. Beaumont was called to treat him.

Dr. Beaumont cleaned the wound and put the dressing. After one and a half years, the doctor found that Martin’s wound had healed except for one thing.

He had a big hole in his stomach. The hole was covered with a loose flap of skin, like the washer in a football. Press the skin and you could peep into Martin’s stomach! Not only that, the doctor could also take out food from the stomach by putting a tube in the hole.

Dr. Beaumont felt he had found a treasure. Can you guess how much time he spent on doing different experiments on this stomach?

Nine years! During this time Martin grew up and got married. At that time scientists did not know how food was digested? How does the liquid (digestive juices) in the stomach help? Does it only help in making the food wet and soft? Or does it also help in digestion?

Dr. Beaumont took some liquid (juices) out of the stomach. He wanted to see what would happen to a food item kept in a glass filled with it. Would it get digested on its own? For this he did an experiment. With the help of a tube, he took out some digestive juice from the stomach.

At 8.30am he put twenty tiny pieces of boiled fish in 10 millilitres of the juice. He kept the glass at the same temperature as that of our stomach – about 30°C. When he checked at 2 pm he found that the pieces of fish had dissolved.

Dr. Beaumont tried this experiment with different food items. He gave Martin the same food at the same time and then compared how long it took for food to be digested in the glass and in Martin’s stomach. He recorded his observations in a table.

So, what does our stomach do? Dr. Beaumont did many experiments and found out many secrets about digestion. He found that food digests faster in the stomach than outside. Did you notice this in the table?

Our stomach churns the food to digest it. The doctor also saw that the food did not digest properly when Martin was sad. He also found that the juice in our stomach is acidic. Have you heard of anyone talking about acidity -especially when that person has not eaten well or the food is not digested properly.

Dr. Beaumont’s experiments became famous across the world. After this many scientists did many such experiments. What did you say? No, they did not shoot people in the stomach. Nor did they wait for a patient with a hole in the stomach. They used other scientific ways to look inside our bodies.

 Children Did you like the story of Martin or, should we say, the story of our own stomach?





Children in this lesson we are going to learn about Spoilage and wastage of food,preservation of food(drying and pickling).

Food spoilage means the original nutritional value, texture, flavour of the food are damaged, the food become harmful to people and unsuitable to eat.
There are three types of microorganisms that cause food spoilage -- yeasts, moulds and bacteria. 
yeasts and moulds can thrive in high acid foods like fruit, tomatoes, jams, jellies and pickles.
Bacteria are round, rod or spiral shaped microorganisms. Bacteria may grow under a wide variety of conditions. There are many types of bacteria that cause spoilage.
Fungal Spoilage: Blue mould rot in tomato caused by Penicilliumi spp,
Watery soft rot in apple caused by Sclerotinia sclerotiorum.
Bacterial Spoilage: Soft rot in tomato caused by Erwinia carotovora.
Enzymes are proteins found in all plants and animals. If uncooked foods are not used while fresh, enzymes cause undesirable changes in colour, texture and flavour. Enzymes are destroyed easily by heat processing.
Oxidation by air:
Atmospheric oxygen can react with some food components which may cause rancidity or color changes.
Microorganisms, specifically bacteria, molds, and yeasts, can cause food to spoil. For example, microorganisms that break down fats in unsalted butter can cause it to become rancid. Bacteria that breaks down protein in meat (proteolytic bacteria) and results in foul odors.

Biji returned the bread:
Aman’s Biji went to the market to buy bread. The shop was very crowded. The shopkeeper picked up a packet of bread and gave it to Biji. She looked at it and returned it immediately.
How does food get spoilt?
The whole class can do this experiment together. Take a piece of bread or roti. Sprinkle a few drops of water on it, and put it in a box. Close the box. See the bread or roti everyday until you find some changes on it.
Make this table on a chart paper and put it up in the classroom. Fill up the chart every day after discussing the changes seen.
So children the fod gets spoiled easily.bacteria and fungi grow well at room temperature in the presence of moisture. Cereals and pluses do not get spoiles easily as there is no moisture in them.
Spolit food it unfit for consumption. It taste bad and can causes disease.
Therefore, it has to be prevented from spoilage. This prevention is termed as preservation.
Food can be presrved by the following methods. We can stored food by this following five methods.
1. Cooling Or Refrigeration
2. Jellying
3. Pickling
4. Drying Or Dehydration
5. Tetra packing
6. Canning
1. Cooling Or Refrigeration: food spoiling bacteria do not grow in cold temperature. So, this is a common way of preservation.
2. Jellying: fruits like strawberries, mangoes and pine apples are preserved by this method. The fruit pulp is a boiled in sugar syrup. Sugar acts as a preservative. Jams and fruits are preserved in this way.
3. Pickling: seasonal fruits like mangoes, lime, amla and garlic are preserved by pickling. For this we add `salt, vinegar and oil are used as preservatives in pickles.
4. Drying Or Dehydration: the food can also be preserved by drying in the stem. Spices like chillies and ginger, papadas and food grains are preserved by drying in the sun. Dry means removing the moisture content of the food which promotes the growth of bacteria.
5.Tertra packing : this method is similar to canning but is used for liquids. Here, the food is heated to very high temperature and then packed in terapacks .
Ex: milk, juice, oil, and ghee are stored in this way.
6. Canning: in this process the food is heated temperature to kill the food spoiling bacteria and then stored in air tight cans or bottles.
Food preserved helps in preventing wastage of food from the spoiling. It also helps us to store food and use it when it required whole the year. All preserved foods have a shelf life. While buying and using preserved food, we should check the expiry date mentioned at the label of the product.
Summer treat – Mamidi tandra:
Chittibabu and Chinnababu live in Atreyapuram town in Andhra Pradesh. The brothers spend the summer holidays playing in the mango garden, when the trees are full of fruits. They also like to eat unripe mangoes with salt and chilly powder.
At home, their mother cooks unripe mangoes in different ways. She also makes many kinds of mango pickles. The pickles last through the year until the next mango season. One evening, while having food Chinnababu asked, “Amma, we have so many mangoes. Make some mamidi tandra (aam papad) from them.”
Their father said, “Making mamidi tandra needs four weeks of hardwork. If you both promise to help us everyday for the next four weeks, we can together make the mamidi tandra.”
Both the brothers quickly agreed to help. The next day both the children went to the market with their father. They bought a mat woven from the leaves of a palm tree, poles of casuarinas tree, string made of coconut husk, some jaggery and sugar. Amma found a sunny place in the backyard. Both the brothers made a high platform by using poles. They spread out and tied the mat on that platform.
The next day, Appa chose the most ripe mangoes.  They took out the mango pulp into a large pot. Then they strained the pulp through a fine muslin cloth, to remove the fibres from the pulp.
Then Chittibabu crushed the gur (jaggery) till there were no lumps. They added the jaggery and sugar in equal amountsto the pulp.
Chinnababu mixed the jaggery and sugar well with a big spoon. Amma then spread this pulp into a thin layer over the mat. The thin layer was left to dry in the sun. In the evening, they covered the mat with a clean saree to avoid any dust.
The next day they again took out some mango pulp. They added jaggery and sugar into the pulp. Then they spread the pulp over the previous day’s layer. This work was given to both the brothers. Both of them together spread many layers over it.
For the next four weeks they hoped that it would not rain. For four weeks, they added layer after layer until the jelly grew four centimetres thick and looked like a golden cake.
After some days Amma said, “The mamidi tandra is ready, we can
take it out and cut it into pieces tomorrow.” The next day, the mat was brought down from the platform.
Mamidi tandra was cut into smaller pieces. The brothers tasted it. It was tasty. Chhinnababu said, “Wow, how tasty! After all we have also helped in making it.”