Introduction

Food is needed by all living beings for four main purposes:

  • for their growth.
  • to provide energy for doing work.
  • for the repair and replacement of the damaged tissues.
  • to provide resistance and protection against diseases from infections.

If a person does not get food, she/he feels weak and is likely to fall ill.

Different people have different choices of food.

There is a wide range of food items eaten across various states of India. Different organisms eat different kinds of food.

Human beings are omnivores.

Our food comes from different sources.

We get food from plants as well as animals.

We eat animals (as meat) as well as their different products like milk, eggs and honey.

Cooked food can be easily consumed and absorbed by our body. Cooking also kills the harmful germs.

We should have sprouted seeds every day. Sprouted seeds are rich in nutrients.
Food Where Does It Come From Class 6 Notes Science Chapter 1

Introduction

Agriculture is the science, which mainly deals with the diverse processes or the methods used for the cultivating different varieties of plants and livestock farming or animal husbandry on the basis of human requirements. The entire world ia depends on agriculture for its food. Therefore, it is very important to produce and store the harvested crops carefully.

Introduction

Introduction
A substance which gives energy and keeps the body in good health is called food. Several types of nutrients constitute food. Food is one of the basic requirements of all living organisms. In fact, no organisms need food for their growth and development. Food also provides energy for various life processes in the body. Food is necessary for both plants and animals.

Introduction

Why do we need Food?

  • We know that all living things be it plants and animals need food and water to live on.
  • We need food because food gives us energy.
  • The food we eat gives our body essential nutrients to help us grow and heal when we are injured or are ill.
  • Thus food keeps us healthy and provides us with essential nutrients to fight diseases and maintain body functions.

 

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

 

  • Food Definition: - It refers to the edible substances consumed by humans and other animals in order to obtain energy for various tasks as well as growth and development.
  • We must NEVER WASTE food in any way.
  • We must consume food four times a day to remain healthy -> Breakfast, Lunch, Evening Snacks, Dinner.

Importance of Food

  • The importance of food for living organisms is as follows:
    1. It helps in the growth of living organisms.
    2. It also helps to repair and replace damaged parts of the body.
    3. This provides the energy required for various activities.
    4. It provides protection from infections and various diseases.
    5. It helps in the overall growth and development of an organism.
  • We must eat different kinds of food at different times for proper Nutrition.
  • Different people eat different types of food according to their habits, lifestyle, taste, region, religion, availability and various other factors.
  • Even in a single-family different people have different choices of food.

What do Animals Eat?

All animals need food to survive. Animals eat many different kinds of foods including other animals, fish, nuts and seeds, tree leaves and branches, insects, and grass.There are three categories on basis of which animals are divided for their food.

Animals that eat only plants are called herbivores. Most herbivores, including the giraffe, macaw, ground squirrel, and elephant.

Animals that eat only other animals are called carnivores. Polar bears, sharks, woodpeckers, and anteaters are all examples of carnivores.

Omnivores eat both plants and animals. A typical grizzly bear, for example, will eat just about anything it can catch and get its mouth around. Grizzlies are known to kill their own food, including deer, but will also scavenge the carcasses of dead animals. They also eat fish, amphibians, small mammals, insects, berries and tree buds.

What do Animals Eat?

Food : A necessity for human life
*    Food is essential for all living organisms because of the following reasons :
(i)     For energy requirement  to perform various functions of body to sustain life. 
(ii)    For growth : You have seen yourself growing. Without proper food, your growth would not be possible. 
(iii)    For repair of damaged or injured body parts ; when you get hurt,your skin is damaged and the blood is lost. Repair of such damaged parts takes place by the addition of new cells. 
(iv)    For protection from diseases and infection.

Food Variety

Foods eaten by living organisms
On the basis of their food habit, animals are of three types : 
(i)  Herbivores  : Animals which eat  plants and plant products – these are called herbivores. e.g.  Cow, sheep, deer elephant etc.  
(ii)  Carnivores :  Animals which eat flesh of other animals are called carnivores. e.g. Lion, Tiger, Fox, Wolf etc.
(iii)  Omnivores : Animals eating both plants and animals are called omnivores.e.g. Humans, crow, squirrels and cockroaches.
 

Food Variety

Introduction

Why do we need Food?

  • We know that all living things be it plants and animals need food and water to live on.
  • We need food because food gives us energy.
  • The food we eat gives our body essential nutrients to help us grow and heal when we are injured or are ill.
  • Thus food keeps us healthy and provides us with essential nutrients to fight diseases and maintain body functions.

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

  • Food Definition: - It refers to the edible substances consumed by humans and other animals in order to obtain energy for various tasks as well as growth and development.
  • We must NEVER WASTE food in any way.
  • We must consume food four times a day to remain healthy -Breakfast, Lunch, Evening Snacks, Dinner.

Importance of Food

  • The importance of food for living organisms is as follows:
    1. It helps in the growth of living organisms.
    2. It also helps to repair and replace damaged parts of the body.
    3. This provides the energy required for various activities.
    4. It provides protection from infections and various diseases.
    5. It helps in the overall growth and development of an organism.
  • We must eat different kinds of food at different times for proper Nutrition.
  • Different people eat different types of food according to their habits, lifestyle, taste, region, religion, availability and various other factors.
  • Even in a single-family different people have different choices of food.

FOOD VARIETY

What are ingredients?

  • Food Ingredients are the materials required to prepare the dish we consume as food.
  • Food Ingredients can be obtained from plant sources and animal sources.
  • To prepare food we need different kinds of ingredients for example - To cook vegetable curry we need different types of vegetables, salt, spices oil and so on. Another example is to prepare vegetable curry, we need different kinds of vegetables, salt, spices, oil

IngredientAny substances or materials that are required to produce a dish are called Ingredients.

Example: Atta (flour) and water are the two ingredients required to make a chapatti.

  • The table given below shows some food items and major ingredients used to prepare them

Food Materials and Sources

Plants are usually grouped into herbs, shrubs, trees, and climbers based on their height, stems and branches.

  • Herbs are small plant which have soft stem.
  • Shrubs are bushy and medium sized plants and they are somewhat bigger than herbs. Their branches start from just above the ground.
  • Trees are tall and large plants with hard and woody stem. 
  • Plants with weak stem that cannot stand upright and spread on the ground are called creepers.

Food Materials and Sources

Source of food
There are two main sources of food in the world for all human beings – namely plants and animals.
*    Plants as Source of Food : Foods obtained from plants are of different types — cereals, pulses, vegetables, fruits, oils, sugar, tea, coffee and spices. 
(i)  Cereals are the most important sources of food for man and animals. They are rich sources of carbohydrates. Three most important cereals are wheat, rice and maize. These cereals are obtained from grains (biologically, grains are fruits of a plant).
(ii)   Pulses or Legumes (commonly called 'dals') are rich in proteins and are obtained from plants.
(iii)  Vegetables are rich sources of vitamins, minerals and roughage.Water content in vegetables is high (70 to 90 per cent) and their food value is low. 
(iv)  Fruits have high water content, low food value, but are rich in minerals and vitamins. In common usage, the term 'fruit' is used for those which are usually eaten without cooking. 
Common fruits are banana, mango apple, grapes, pineapple, guava, orange, litchi, and so on. 

(v) Sugars are produced by the green plants through photosynthesis. Chief sugar producing plants are sugarcane and sugarbeet. 
In case of sugarcane, the plant part used is the stem, while in sugarbeet, it is the root. 
(vi) Tea and coffee are common beverages, Tea is obtained from leaves, while coffee is obtained from seeds.
(vii)   Spices have no food value and are used for adding flavour to food. Before the advent of refrigeration, spices were also used for preserving foods.
The important spices are pepper (kali mirch), cardamon (ilaichi), ginger (adrak), turmeric (haldi) and chillies (mirch), cloves (loung), saffron (kesar), fennel (saunf), cumin (jeera), coriander (dhania), asafoetida (heeng), fenugreek (methi), nutmeg (jaiphal) and thyme (ajwain). 
(viii)    Oils : Oils are rich in fat and provide energy. Cotton, groundnut, mustard, coconut, soyabean and sunflower seeds give us oil.
(ix)    Medicines : Some plants have medicinal value and are used for curing certain diseases especially in Ayurveda. Mint, Basil (tulsi), ginger, fenugreek (methi), etc. are used in medicines.

Food Materials and Sources

Food Materials and Sources

Plant Part As Food

Sources of Food

Let us now learn about food variety and food sources.

  • Plants and animals are the two sources of our food materials. So, we obtain food from plants as well as animals.
  • Milk, egg, meat, chicken, fish, prawn, beef, pork etc. are the food products that we get from animals.
  • Grain, cereals, vegetables and, fruits are the source of food that comes from plants and plants products.

Plant Source

  • For us, several parts of the plant serve as sources of food. We eat fruits, vegetables, cereals, and pulses etc, which are types of food that come from various portions of a plant.
  • For example, we eat leafy vegetable, fruits, and some parts of plants like stem and roots.
  • Green plants -> are called PRODUCERS because they prepare their own food using lightair (carbon dioxide), water, & chlorophyll (green pigment present in trees) by the process of photosynthesis.
  • So, we can say that green plants are the primary source of food.

FigurePlant-parts-as-food.png

  • Table Given below shows various edible plant parts that serve as food sources for us.

  • When the seeds begin to grow (or germinate) by developing tiny roots, they are called Sprouts
  • The food value of seeds can be increased by converting them into sprouts
  • They are a rich source of vitamins like vitamin A, B & C
  • The method of converting seed into sprouts is called Sprouting.

Plant Parts and Animal Products as Food

Plants Parts as Sources of Food :
Table : Edible Parts of Some Plants

Animals as Sources of Food : Animals provide us food in the form of milk, meat, fish , eggs and honey. 
(i)     Milk - yielding animals : Cow and buffalo. 
(ii)     Meat - yielding animals : Sheep, goat and pig. Meat of pig is called pork. 

(iii)   Poultry animals : Birds like hen, duck and turkey. 
Poultry products are rich sources of proteins and have right kind of fat for good health . 
Animals which provide meat and egg are called poulty animals.
(iv)    Fish : Fish is a major source of food rich in animal proteins. Fish proteins have high digestibility and growth-promoting value. Also, cod and shark liver oils are rich in vitamin - D. In India , fish are found both in fresh water (ponds, lakes and rivers) and sea water. 

*   Fresh Water Fishes : Catla, Labeo, Pirrhina, Barbus, Mystus, Clarius. 
*    Sea Water Fishes : Hilsa, cat fish, sardines, ribbon fish, red mullet, pomfret, bombay duck.Rearing and management of fish on a large scale is known as pisciculture.
    
(v)  Honey bees : The insects which provide us honey are known as honey bees. The honey bees collect necter (sweet juice) from flowers, convert it into honey and store it in their nest, which is known as the beehive.
The rearing of honey bees on a large scale is known as apiculture. The place used for the rearing of honey bees is called an "apiary". Honey is produced by honey bees from the necter of flowers. It consists of water, sugar minerals and enzymes. It is an antiseptic (which destroys the growth of micro organisms) and is easily digestible. For this reason, honey is used in medicines.

 

Plant Parts and Animal Products as Food

Plant Parts and Animal Products as Food

Animal Products as Food

  1. Meat – Goat, Chicken, Pork, Fish, Prawns etc. are part of the Non-vegetarian diet.
  2. Egg – Eggs of Hen, Duck, Goose like meat are also part of the Non-vegetarian diet.
  3. Milk – Dairy products obtained from Cow, Buffalo, Camel, Goat in a dairy farm
  4. Honey – Bees collect nectar (sweet juices) from flowers, convert it into honey and store it in their hive.

Plants act as sources of food ingredients such as fruits, vegetables, grains, pulses etc.

Animals are sources of food ingredients such as milk, eggs, meat products etc.

These are shown in the figure above.

Some examples of edible plant parts are shown in the image above and their examples are given below:

  • Roots: beets, carrots, radishes, turnips, ginger,
  • Stems: broccoli stem, bamboo shoots, sugar cane, potato
  • Leaves: spinach, lettuce etc.
  • Fruits: apple, pear, tomatoes, grapes, cherries, oranges
  • Edible Flowers: broccoli heads, cauliflower heads
  • Seeds: sunflower seeds

Plant parts as food

Food habits of people : In our country, people of different states have different food habits. Food habits are affected by food production and supply. Let us know the food habits of people in different Indian  states. 
(i)     Andhra Pradesh : Rice, dry vegetable preparation, arhar dal , upma, dosa, rasam, curd, pickle etc. 
(ii)     Bihar : Rice chapati, sattu (flour of roasted gram), dal, baingan ka bharta (brinjal preparation), bachka (thin slices of vegetales coated with besan), bhujya (of potato and oninon), pappad, chutni etc. 
(iii)   Gujarat : Chapati, rice dal, vegetable preparaton, lassi (buttermilk), thepla (fried chapatis made of wheat flour), dhokla, khandvi etc. 
(iv)   Punjab : Roti, parantha, missi roti, butter, lassi (buttermilk), pulses, curd, sarson ka saag, chole, gajar ka halwa, dahi bhalla etc. 
(v)   Rajasthan : Bajra, dalia, roti, dal, kachori, sev (a besan preparation), vadi (moong dal preparation), dal-bati.
(vi)  Tamil Nadu : Idli, dosa, rice sambhar, banana chips, etc. 

Plant parts as food

Table Given below shows various edible plant parts that serve as food sources for us.

  • When the seeds begin to grow (or germinate) by developing tiny roots, they are called Sprouts
  • The food value of seeds can be increased by converting them into sprouts
  • They are a rich source of vitamins like vitamin A, B & C
  • The method of converting seed into sprouts is called Sprouting.

Important Definitions

Nectar: The juicy sweet liquid secreted by within flowers which is sucked by bees and is made into honey by them

Sprouting: The process by which seeds shoot out small white structures as way of growth is called Sprouting.

Cellulose: It is a substance that is found in the cell walls of a number of plants. It is an indigestible fiber and is found in grass.

Enzymes: It is defined as a chemical substance that helps in bringing about changes to certain other substances without undergoing any changes in themselves.

What do Animals Eat?

*   Functions of food :  
    •    Food provides energy.
    •    Food helps in growth and development.
    •    Food helps in the replacement of worn out tissues, repair of damaged cells and healing of wounds.
    •    Food protects the body against diseases.

*    Basal metabolic rate (BMR) : The smallest amount of energy that body needs to keep alive is called basal metabolic rate (BMR).
 

What do Animals Eat?

What do Animals Eat?

Animals can be classified into three broad categories in terms of what they eat as can be seen in the image above,

Different Type of Animals

Herbivores

Animals which eat only plants and plant products are called herbivores. For example: Elephant, rabbit, horse, Cow etc.

Carnivores

Animals which eat other animals are called carnivores. For example: Lizard, Lion, tiger, crocodile etc.

Omnivores

These animals eat both plants and animals. For example: Dog, cat, crow, etc.

First we have the Herbivores i.e. plant eaters. They only consume plant parts. Examples: Cows, goats, deer, giraffe etc.

Next we have the Carnivores i.e. meat eaters. They only consume meat of other animals. Examples: Lions, tigers, vultures etc.

Last we have Omnivores i.e. animals who eat both plant parts and meat products. Examples: Humans, bears etc.

  • Animals are unable to produce their own food by the process of photosynthesis, they only consume food made by others, and hence called CONSUMERS.
  • Animals are grouped into 3 categories based on their food habits.
    1. Herbivores - Herbivores Animals are those animals that feed on plants i.e, these are animals that eat only plants or plant products.
    2. Carnivores - Carnivorous animals are those animals who eat other animals. So, carnivores Animals that feed on other animals are called carnivores.
    3. Omnivores - animals that eat both plants and animals.
  • Table given below shows examples of different types of animals

Special characteristics of Herbivores

  1. Herbivores like a cow, horse, and goat have wide, blunt teeth which are suitable for pulling plants off the ground and grinding them.
  2. Herbivores like cow and camel have the ability to bring back previously swallowed food to the mouth for chewing it the second time. This helps them to absorb most of the nutrients from hard-to-digest food like grass.
  3. Squirrels have a pair of broad, sharp-edged front teeth (incisors) in each jaw They use these teeth to gnaw food items like nuts.
  4. Butterfly and hummingbird do not need to worry about chewing their food. They have mouth parts shaped like a straw to suck nectar from flowers.

Special Characteristics of Carnivores

  1. The diet of carnivores is rich in fats and proteins
  2. Carnivores animals like lion and tiger have sharp and pointed front teeth (canines). They also have sharp claws and powerful jaws which help them to tear flesh.
  3. Carnivorous birds like eagle have curved, pointed beaks that allow them to tear flesh.
  4. Carnivores like chameleon and frog have a long, sticky tongue that they use to catch insects.
  5. Carnivorous fish like a shark has several small, sharp teeth that help them bite off chunks of flesh.
  6. Carnivores such as snakes swallow their prey (prey are animal that is hunted or killed for food) whole.

Special Characteristics of Omnivores

  1. Omnivores like a bear and human beings have different types of teeth that help them to eat both plants and the flesh of other animals.
  2. Omnivorous birds like crow have a sharp and pointed beak to help them eat a
    variety of food.

Scavengers and Decomposers:

  1. Scavengers are birds and animals which eat the flesh of other dead animals. Eg: Vulture.
  2. Decomposers are organisms that feed on and destroy (or decompose) dead plants and animals. E.g.: Fungi and bacteria
  3. Both scavengers and decomposers play a very important role in cleaning the environment. Without them, our planet would be covered with dead plants and animals.

There are five major components of food namely vitamins, minerals, proteins, carbohydrates and fats. While the diet of carnivores is rich in fats and proteins, there are some necessary vitamins and minerals in plant-based foods that their diet lacks. Similarly, an all plant-based diet lacks in a good amount of protein and certain minerals.

It is important to know that there is difference between vegetarians and herbivores. While vegetarians make a conscious decision to not eat meat, herbivores on the other hand are incapable of eating meat and dairy products. Similarly, carnivores lack the necessary enzymes in their stomachs to digest cellulose which is a major component of green food like grass. 

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