Class-6 Science Notes

Chapter 1 : Food Where Does it Come From

Food

  • Anything which we eat to live is calledfood.

  • For example: Roti ,bread ,butter ,fruits vegetables, pulses, vegetable oil, butter, desi ghee, eggs, meat, chicken , fish, egg etc.

  • Food is necessary for us because it provides matter for the growth of our body and energy to do work .

  • Food is a substance eaten by us to do work, grow ,maintain our body and remain healthy.

  • Animals eats food to live.

Variety in the food

  • We eat different kinds of food at different times and on different days.

  • Different people eat different types of food according to their habits, lifestyle , taste , availability.

For Example : Some people eat food prepared from wheat (chapatti ,bread ,noodles), fruits, vegetables, rice,  dosa, idli, meat, chicken, fish.

  • A particular variety or preparation of food served as part of a meal is called 

  • Any of the foods or substances which are combined to make a particular dish are called 

Food items and their ingredients

  • The various food items which we eat daily are usually made up of more than one material or ingredients.

For example : Boiled rice :  rice + water

  • Chapatti: Atta + water

  • Vegetable curry :  salts +spices +oil+ water

  • Pulses :  dal +salt + spices +oil +water

  • Idli : rice + urad dal +salt +water

  • Examples of cooking oil are Mustard oil, Sunflower oil and Coconut oil.

Plant Parts as Food

Cereals

  • The main sources of food from plantsare food grains (wheat, rice, maize), pulses, fruits, vegetables, oils, sugar, spices, tea, coffee.

  • Grains used for food are called food grains or cereals.

Plant parts as food

  • The various parts of plants which are used as food material by us are: Roots, stems, leaves, flowers, fruits, seeds.

(1) Plant roots as food

  • We eat the roots of some plants as food.

  • For example:carrot, radish, beetroot, sweet potato, turnip.

(2) Plant stem as food

  • Some plants store food in their stems (modified or underground). We eat the stems of such plants as food.

  • For example: onion, potato, ginger, garlic, turmeric.

(3) Plant leaves as food

  • The leafy vegetables are the leaves of the plants.

  • For example: spinach, cabbage, lettuce, leaves of mustard plant.

(4) Flowers as food

  • The flowers of some of the plants are eaten as food.

  • For example:flowers of banana plant, pumpkin plant, sunflower, Jasmine.

(5) Fruits as food

  • There are some plants which store food in their fruits.

  • We eat the fruits of such plants as food.

  • For example:apple, orange, mango, pears, banana, plum, grapes, guava.

(6) Seeds as food

  • Some of the plants store food in their seeds. We eat the seeds of these plants as food.

  • For eg: wheat, rice Maize, millet, Peas, pulses, mustard, groundnut, soyabean.

  • Groundnut and mustard  seeds are called oilseedsbecause they are used to extract edible oils which are used for cooking food.

Mustard plant have two edible parts

(1) Leaves are used as leafy vegetable

(2) Seeds of mustard plant are used to extract mustard oil.

  • The fruit of banana plant are used as food and the flowers of the banana plant are also used as food in the form of vegetables.

Sprouts

  • When the seeds begin to grow by developing tiny roots, they are called 

  • The sprouts contain more of Vitamin A, B, C which makes them a more nutritious food.

  • The method of making sprouts from seeds is called 

  • The seeds of moong, chana, moth are usually converted into sprouts in our homes.

(1) Some dry seeds of Moong/ moth /chana.

(2) Put a small quantity of seeds in a container filled with water and leave this aside for a day.

(3) Next day, drain the water completely and leave the seeds in the vessel.

(5) A white structure may have grown out of the seed. This is called sprout.

Animal Product as Food

  • Animal products which are used as foodare eggs, chicken, mutton, fish, honey, milk etc. 

  • Milk is used for drinking purpose, converted into other useful products such as curd, butter, ghee, cheese. Fish gives us cod liver oil which is rich in vitamin A.

  • Honey is produced by honey bees. Bees collect nectar (sugary liquid) from the flowers and convert it into honey. The  bees store this honey in the structure called 

  • The hives containing honey are called honeycombs. Honey is collected from such honeycombs.

  • Human being eats plant food as well as animal food.

The animals eat only a few type of food :

1 Buffalo and cow : grass, grains, hay, oil cakes

2 Goats : grass, leaves of plant, grains

3 Dogs : plant food (chapatti, bread ), animal food (meat ), drinks milk

4 Cat : rat, drinks milk, birds

5 Rat : grains, paper cloth

6 lion or tiger : flesh of forest animals

7 Bear : small forest animals, fruits

8 Rabbit :carrot, grass, leaves of plants

9 Vultures : flesh of dead animals

10 Crow : grains, insects

11 Frogs : insects, worm

12 Sparrow : grains, small insects

13 Pigeon : grains

14 lizard : insects

15 Fish :small aquatic plants and animals

Food Producers and Consumers

Photosynthesis

  • Green plants make their own food by the process of photosynthesis.

  • Green plants absorb water from the soil, carbon dioxide gas from air, energy from sunlight and make food.

Producers

  • Since green plants make their own food they are called producers.

Consumers

  • Animals are unable to make their own food by process of photosynthesis, they depend on plants for food. Animals only consume food made by others, they are called consumers.

  • On the basis of their food habits, all the animals can be divided into three groups.

  1. Herbivores

  2. Carnivores

  3. Omnivores

Herbivores

  • Those animals which eat only plants are called herbivores.

  • Herbivores eat grass, leaves, green fruits, bark of tree.

  • For example :cow, goat, buffalo, horse, deer, ox, camel, rabbit, monkey, giraffe, elephant.

Carnivores

  • Those animals which eat only other animals are called carnivores.

  • Carnivores eat only the meat of other animals.

  • For example :lion, tiger, vulture, lizard, wolf, Leopard, snake, seal.

  • Carnivores are meat or flesh eaters.

Omnivores

  • Some animals eat both plants as well as other animals as food. Those animals which eat both plants and animals are called omnivores.

  • For example :dog, cat, monkey, hen, sparrow, bear.

  • Omnivores are plant as well as meat eaters.

Our food has 7 components:

(1) Carbohydrates

(2) Fats

(3) Proteins

(4) Vitamins

(5) Minerals

(6) Water

(7) Roughage

Carbohydrate

Function

  • They provide energy to our body.

  • For Example :glucose ,sugar starch( it comes from cereals like wheat and rice)

  • Wheat –> Chapatti ,bread ,noodles

  • Rice—> Idli, Dosa

  • Potatoes contain a lot of carbohydrates.

  • Sources of Carbohydrates are wheat, rice, Maize, millet, potato, sweet potato ,sugar, honey, banana ,mango, papaya etc.

Test for presence of starch

  • The presence of starch in food item can be tested by using a dilute iodine solution.

  • This test is based on the fact that iodine produces a blue – black colour on combination with starch.

  • A food items which gives a blue black colour on adding a few drops of dilute iodine solution will contain starch.

  • A food item which does not produce a blue black colour on adding dilute iodine solution will not contain starch.

Procedure

  • Take a small quantity of the food to be tested.

  • Add 2-3 drops of dilute iodine solution to the food with a dropper.

  • If a blue black colour is produced then starch is present in the given food.

Fats

  • Fats also provide energy to our body. They provide us twice as much energy as that provided by the same amount of Carbohydrates.

  • For example:butter ,ghee, milk ,cheese, oil (groundnut ,mustard ,sunflower, coconut), egg yolk, meat ,cashew, soybean.

  • Fats are solid at room temperature and oils are liquid at room temperature.

  • Fats as well as carbohydrate provide energy, therefore they are called energy giving food.

  • Plant sources of fatsare groundnut oil ,mustard oil ,coconut oil ,Sunflower oil , til, nuts.

  • Animal sources of fatsare butter, ghee, milk, cheese, eggs ,meat.

Test for Fats

  • A translucent object is one which allows light to pass through it partially.

Leave a Reply

Your email address will not be published. Required fields are marked *