LESSON -9 GERMS AND DISEASES

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1 LESSON -9 GERMS AND DISEASES WEB CHART MICROBES VIRUS BACTERIA FUNGUS PROTOZA MEASLES TYPHOID RINGWORM MALARIA DEFINE:- 1. MICROBES- Those organisms which are very small and can only be seen through microscope are called microbes. 2. GERMS- Microbes that causes diseases are called germs. 3. DISEASE- A disease is an abnormal condition in which the body is not able to function properly. 4. COMMUNICABLE DISEASE- The disease that spreads from one person to another is called communicable disease. 5. PASTEURIZATION- Heating of milk at high temperature for at least half an hour and cooling it quickly to kill harmful germs is called pasteurization. 6. DECOMPOSERS- Some microbes feed on dead plants and animals to form compost are called decomposers. 7. VACCINE- Vaccine is a small amount of disease causing germs that have been weakened or killed. It is given orally or injected into the body to protect us from many diseases. 8. CONGENITAL DISEASE- A disease that is present in a child from birth is called congenital disease. 1 P a g e

2 SHORT ANSWERS- Q1. How do germs spread by contact with sick person? ANS1. Germs spread by touching or using the belongings of sick person. It also spreads by eating, drinking or coming in direct contact with a sick person. Q2. Why should mattresses, linen and clothes be exposed to sunlight? ANS2. Mattresses, linen and clothes should be exposed to sunlight, as sunlight is a natural disinfectant. It helps to prevent the growth of germs. LONG ANSWERS- Q1. List the ways in which microbes are useful to us. ANS1. Some microbes are useful to us in following ways- 1. Some bacteria change nitrogen gas from the atmosphere and helps in development of plants. 2. Some bacteria and fungus are use to make antibiotics. Eg. Penicillin. 3. Microbes present in the digestive system helps in the digestion of food. 4. A fungus called yeast helps in making bread. 5. Lactobacillus helps to change milk into curd. 6. Some microbes acts as decomposers. Q2. How do germs spread through contaminated food and water? Name disease caused by consuming infected food and water. ANS2. Germs grow on stale food. Flies, cockroaches and rats carry germs from dirt, garbage and severe. When they sit on our food it gets infected and on consumption of this food and water disease is spread cholera, dysentery, diarrhea, and typhoid are caused by consuming infected food and water Q3. How do mosquitoes spread malaria and dengue? ANS3. Malaria and dengue are spread through blood sucking mosquito, like female anopheles and aedes mosquitoes bites an infected person it 2 P a g e

3 sucks the germs along with the blood. When this mosquito bites a healthy person germs and passed onto the person spreading diseases. Q4. What are the various ways in which we can protect ourselves from communicable diseases? ANS4. Following are the various ways in which we can protect ourselves from communicable diseases 1). By keeping ourselves clean brushing teeth, bathing and wearing clean clothes. 2). Disinfecting rooms, bathrooms and toilets. 3). Keeping the surroundings clean and spraying oil on the stagnant water. 4). Washing the fruits and vegetables before eating or cooking. 5). Boiling or using filter to kill the germs present in drinking water. 6). Getting vaccinated to protect us from diseases. Q5. What are allergies? How are they caused? ANS5. An allergy is a condition that makes some people sick because they have eaten, touched or inhaled something. They are caused by inhaling dust, pollen grains, smoke from fire crackers or vehicles and perfume. They are also caused by eating, drinking, touching or cleaning cupboards or old books. 3 P a g e

4 Protozoa fungus virus bacteria 4 P a g e

5 LESSON 2 SYNTHETIC MATERIALS FIBER NATURAL SYNTHETIC Cotton Leather Polyester Nylon Wool Jute Rayon Acrylic DEFINE 1. MATERIAL A material is a substance from which things can be made. 2. NATURAL AND SYNETHETIC MATERIAL - Those materials which occur naturally are called natural materials. EG - cotton, wood. Those materials are by combining chemicals which are called synthetic materials. EG plastic, glass, steel. 3. LATEX A milky fluid that comes out from a cut part in the plants is called latex. 4. NATURAL AND SYENTHETIC FIBERS - `Those fibres which are obtained from plants and animals are called natural fibres. EG cotton, wood. Those fibres that are manufactured from chemical substance and are manmade are called synthetic fibres. EG polyester. 5. ADHESIVES Materials that are used to stick things together are called adhesives. 5 P a g e

6 SHORT ANSWERS- Q1.Name four synthetic fibres commonly used. ANS1. Four commonly used synthetic fibres are- 1. Nylon 2. Rayon 3. Polyester 4. Acrylic. Q2.State two uses of nylon. ANS2. Two uses of nylon are- 1. Used for making tooth brush bristles, ropes. 2. To make cloths, socks, curtains etc. Q3. Why do synthetic fabrics cause discomfort and skin allergies in summer? ANS3. Synthetic fabrics causes discomfort and skin allergies in summer because they do not absorb sweat and moisture easily. Q4. State uses of synthetic rubber ANS4. Synthetic rubber is used for making chewing gum, tyres, surgical gloves, rubber bands, doormats. Q5. Why plastic containers should not be used for heating food in microwave? ANS5. We should not use plastic containers for heating food in microwave because some chemicals from plastic can enter the food and harm us in long run. WRITE LONG ANSWERS Q1. Differentiate between natural and synthetic material. Ans1. NATURAL MATERIAL SYNTHETIC MATERIAL 1). They occur naturally. 1). They are made from chemicals. 6 P a g e

7 2). They do not harm environment. 2). They harm the environment. 3). They are biodegradable. 3). They are non biodegradable. Q2. What are plastics? State advantages and disadvantages of plastic. ANS2. Plastics are type of synthetic material that can be moulded into any shape by applying heat and pressure. AVANTAGES OF PLASTIC:- 1. It is easy to mould it into different shapes by heating. 2. It last long and do not wear out easily. 3. They are low cost, easily available and light weight. 4. They are tough and can bear great pressure. DISADVANTAGES OF PLASTIC:- 1. They do not decay naturally with time, i.e. they are nonbiodegradable. 2. Discarded plastic objects can block drains and pipes. 3. They affect the fertility of soil and health of aquatic life. 4. Burning of plastic results in the release of harmful chemicals that causes air pollution. Q3. List some advantages and disadvantages of synthetic fibres ANS3. ADVANTAGES OF SYNTHETIC FIBRE- 1. They are cheaper than natural fibres and are readily available. 2. They are wrinkle free and easy to wash. 3. Synthetic fabrics dry easily as they do not absorb moisture. 4. They are resistant to insects and moths. DISADVANTAGES OF SYNTHETIC FIBRES- 1. Fabrics made from synthetic fibres burn and melt easily. 2. In case of fire, they stick to the skin and cause severe burns. 3. Synthetic fibres do not absorb sweat and moisture easily. 4. They may cause discomfort and skin allergies. 7 P a g e