Class 6 Science - Food (PDF)

CLASS 6 Food where it come from science  CHAPTER 1 Food Where Does It Come From Food is needed for four main purposes for growth. to provide energy for doing work. for the repair and replacement of the damaged tissues. to provide resistance and protection ag...

CLASS 6 Food where it come from science  CHAPTER 1 Food Where Does It Come From Food is needed for four main purposes for 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. Our food comes from different sources. from plants as well as animals. Food From Plants: Green plants are known as producers because they prepare their own food. They use light, air (carbon dioxide), water, and chlorophyll (present in their leaves) to prepare their food by the process of photosynthesis. Different plant parts serve as sources of food for us. Fruits, vegetables, cereals, and pulses that we eat are obtained from different Roots ofparts of alike plants plant. carrot, radish, turnip, sweet potato, and beetroot are eaten. Stems of certain plants are eaten. For example, the stem of sugarcane plant is eaten and is also used to make sugar. The stem and flower of the banana plant is cooked and eaten in different parts of India. Certain plants have underground stems that we eat. Examples are potato, onion, garlic, and ginger Leaves of plants like lettuce, spinach, cabbage, coriander, mint, and basil are eaten Flowers of certain plants like cauliflower, broccoli, and banana are also eaten Seeds Pulses like mung bean, kidney bean, chickpea, and cereals (wheat, maize, and rice) that we eat are seeds of plants  Wheat grains are ground to make flour (atta) which is used to make chapattis. Cumin seeds, pepper, and cardamom that we eat as spices are also seeds of different plants. Sprouted seeds (or sprouts) of mung bean and chickpea (Bengal gram) are very nutritious. Sprouting involves soaking seeds and draining the water and then leaving them till they germinate.  Fruits and vegetables Plants also provide us fruits and vegetables. Food From Animal: Animal products like meat, egg, honey, milk, cheese, butter, and curd are eaten by human beings. Meat of animals like goat, chicken, fish, and prawns is commonly eaten Hen’s egg is the most common bird egg eaten in the world. It is a rich source of proteins and vitamins. Some people also eat eggs of goose and duck. Honey Honey is a sweet liquid made by bees from the nectar of flowers (Fig. 1.8). Honey is collected from beehives. It is used in cooking and also has medicinal value. Milk Milk is obtained from animals like cow, buffalo, and goat. Products made from milk are known as dairy products. Some common dairy products are discussed below. Paneer (cottage cheese): Common methods of making paneer include adding lemon juice or vinegar to milk. Then, the liquid portion of milk is drained off and the solid part forms paneer. This process is called curdling. Cheese Cheese is made from curdled milk of cow, goat, sheep, or buffalo Cream Cream is made by collecting the top fatty layer of the milk. Butter: Butter is made by churning fresh cream. Ghee Ghee is made by gently heating butter and removing the solid matter. Curd Common methods of making curd include adding a small sample of curd in warm milk. The microorganisms (bacteria) present in the curd sample turn the milk into curd. Unlike green plants, animals cannot make their own food. They depend on plants and other animals for food. People living in deserts also drink camel’s milk. In ice-cold places, people mostly have yak’s milk. Microorganisms Tiny organisms that can be seen only with the help of a microscope. What Do Animals Eat: Different animals have different feeding habits. Based on their feeding habits, animals can be divided into three groups: Carnivores Carnivorous animals (carni, meat; vore, eater) are those that only eat the flesh of other animals. Lion, tiger, jackal, vulture, owl, eagle, snake, and spider are examples of carnivores. Special Characteristics of Carnivores Carnivores 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. Carnivorous birds like eagle have curved, pointed beaks that allow them to tear flesh. Carnivores like chameleon and frog have a long, sticky tongue that they use to catch insects. Carnivorous fish like shark has several small, sharp teeth that help them bite off chunks of flesh. Omnivores Omnivorous animals (omni, all; vore, eater) are those that eat both plants and flesh of other animals. Bear, racoon, crow, and human beings are examples of omnivores.  Herbivores Herbivorous animals (herbi, plant; vore, eater) are those that eat only plants and plant products. Cow, deer, horse, giraffe, squirrel, and butterfly are examples of herbivores. Special Characteristics of Herbivores Herbivores like cow, horse, and goat have wide, blunt teeth. Such teeth are suitable for pulling plants off the ground and grinding them. 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 known as CUD Squirrels have a pair of broad, sharp-edged front teeth (incisors) in each jaw They use these teeth to gnaw food items like nuts. Herbivores like 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 Omnivores Omnivores like a bear and human beings have different types of teeth that help them to eat both plants and flesh of other animals. Omnivorous birds like crow have a sharp and pointed beak to help them eat a variety of food. Scavengers and Decomposers Instead of hunting live animals, some birds and animals eat the flesh of other animals that are already dead. Vulture is one such bird. These animals or birds are called scavengers. Some other organisms feed on and destroy (or decompose) dead plants and animals. Fungi and bacteria are examples of such organisms These organisms are called decomposers. Together with scavengers, decomposers play a very important role in nature. Without these organisms, our planet would be covered with dead plants and animals.