Food has nutritive value that human beings and animals eat or plants absorb in order to maintain life and growth.
➢ Uses of Food in our Body
- It provides us with the energy to do various activities.
- Helps in growth.
- It helps in the repair and replacement of damaged parts of the body.
- Protects us from infections and diseases.
➢ Food Variety
- We eat different varieties of food like rice, bread, vegetables, eggs, butter, sweets, cheese etc.
➢ Ingredients of Food
- Materials needed to prepare any food item are called ingredients. Two or more than two ingredients are needed to prepare a dish.
(i) To prepare boiled rice, rice and water are used, so rice and water are the ingredients for boiled rice.(ii) Atta (flour) and water are the two ingredients required to make a chapatti. Flour(iii) Vegetables, salt, water and spices are used in cooking vegetable curry, so vegetables, salt, water and spices are ingredients of vegetable curry.
Source of Food Materials
Plants and animals are the main sources of food.
➢ Food from Plant Source
- Rice, wheat, vegetables, fruits, etc. are obtained from plant sources. We get these ingredients from certain parts of different plants.
Some examples of edible plant parts are shown below:
Edible Plants(a) Root: We eat the root of radish, carrot, turnip, sweet potato, beet, etc.
(b) Stem: In certain plants, the stem grows underground and store the food. Ginger, potato(underground stem), and onion are stems of plants in which food is stored. So, we eat the stem of ginger, potato, onion, etc.
(c) Leaf: Spinach, Lettuce, Trigonella, etc. We eat the leaves of these plants
(d) Fruits: Orange, grapes, kiwi, apple etc. We eat fruits from these plants.
(e) Oil Seeds: Seeds of many plants are used to extract oil.
Example: Mustard oil is extracted from seeds of the mustard plant. Similarly, sunflower oil, coconut oil, groundnut oil, soyabean oil, etc. are obtained from seeds of respective plants.
(f) Sugar: We get sugar from sugarcane and beetroot.
(g) Tea & Coffee: These are common beverages. Tea is obtained from leaves, while coffee is obtained from seeds.
(h) Spices: They have no nutritive value and are used for adding flavour to food. The major spices are pepper, cardamom, ginger, turmeric. Other spices are cloves, saffron, fennel, cumin, coriander, asafoetida, and fenugreek.
➢ Foods from Animal Source
- We get milk, eggs, meat, honey, fish, etc. from animals. Buffaloes and cow give milk. Hen and duck give eggs. We get meat from goat, chicken, hen etc. Eggs and meat are rich in protein. Fish is a major part of the food for people living in the coastal regions.
(a) Honey: Honeybee produces honey from the nectar of flowers. It is rich in sugar, minerals and enzymes.
(b) Autotrophs: Plants produce their own food by the process of photosynthesis and are called autotrophs.
(Auto: self; troph: nourishment or food)
Green plants: Autotrophs(c) Heterotrophs: Animals; including humans; do not make their own food. They eat food prepared by plants or plant products.
Heterotrophs are divided into the following types on the basis of their food habit:
(i) Herbivores: Animals that eat only grass and plant products are called herbivores. Cow, Elephant, Camel, Deer, Goat, etc. are examples of herbivores.
Herbivore(ii) Carnivores: Animals which eat the flesh of other animals are called carnivores. Lion, jackal, frog, tiger, lizard, snake, etc. are examples of carnivores.
Carnivore(iii) Omnivores: Animals which eat both plants and meat are called omnivores. Crow, monkey, bear, human, sparrow, etc. are examples of omnivores.
Omnivore(iv) Scavengers: Some animals which eat the flesh of dead animals are called scavengers.