Dpsguwahati.org



Class VIIIName of Chapter: Microorganisms: Friend and Foe(35 mins)Week : 9th November – 14th November 2020Period 1: Pg: 22-23Step – IStudy the following topic from textbook:2.4-Harmful MicroorganismsDisease causing microorganismsStep – IIStudy the same topic in the following part of DIKSHA app:Ch – Microorganisms: Friend and FoeStep – IIIIf you have any doubts clear them with your subject teacher (please check name and number of the subject from the school website)Step – IVRead the Bullet points:Pathogens:?Disease-causing microorganisms are called pathogens.Pathogens enter our body through either air, water or municable diseases:?Microbial diseases that can spread from an infected person to a healthy person through air, water, food or physical contact are called communicable diseases.Examples: Common cold, chicken pox, tuberculosisCarriers:?Insects and animals that carry disease-causing microbes and transfer them from one place to other are called carriers or vectors, such as house flies and mosquitoes.Name of some carriers:Female Anopheles mosquito - carries the parasite of malaria called Plasmodium vivax which causes the disease Malaria.Female Aedes mosquito - carries the dengue virus called Flavivirus which causes the disease Dengue.Ways to prevent diseases that spread through air or contact:We should keep a handkerchief on the nose and mouth while sneezing.Keep distance from infected persons.To prevent diseases that spread through the air, keep the patient in complete isolation and keep his or her personal belongings away from others. Vaccination at the suitable age can prevent the onset of tuberculosis, chicken pox, polio, and measles.Ways to prevent diseases that spread through water or food:One should maintain personal hygiene and good sanitary habits and drink boiled drinking water.eat properly cooked food to avoid diseases like cholera.to prevent the spread of polio, cholera, typhoid and hepatitis A, vaccination is effective.Ways to prevent diseases that spread through mosquitoes:We can stop the spreading of diseases caused by mosquitoes (such as malaria and dengue) by not allowing the mosquitoes to breed. We should keep our surroundings clean and dry, and not let water collect anywhere - in coolers, tyres, and flower pots etc.We should also spray insecticides and use mosquito repellents and mosquito nets to protect ourselves from mosquito bites.Step – VQuestion and Answers to be done in the Bio copy:Which of these is a carrier of Dengue virus??????? a)??? Anopheles mosquito b)Female Aedes mosquito c)housefly d)both a and bAns: b) Female Aedes mosquito Carriers are:a)disease causing microbesb)disease carrying microbesc) disease carrying insects and animalsd) all of theseAns: c) disease carrying insects and animalsDefine communicable diseases. Give examples.Ans: Refer bullet pointsMalaria is caused by a ___________ carried by female ________ mosquito.Ans: parasite/protozoa, AnophelesEnd of Day – 1Period 2: Pg:24-25 Step – IStudy the following topic from textbook:Table 2.1Disease causing microorganisms in animalsDisease causing microorganisms in plantsFood poisoningStep – IIStudy the same topic in the following part of DIKSHA app:Ch – Microorganisms: Friend and FoeStep – IIIIf you have any doubts clear them with your subject teacher (please check name and number of the subject from the school website)Step – IVRevise using following Bullet points:Cattle diseases caused by microorganisms: Cattle diseaseCausative organismAnthraxbacterium called?Bacillus anthracisFoot and mouth diseasevirusAnthrax also affects human. Bacillus anthracis was discovered by Robert Koch in 1876.Food Poisoning:Microorganisms that grow on our food sometimes produce toxic substances. These make the food poisonous causing serious illness and even death. This food-borne illness is called food poisoning.Step – VQuestion and Answers to be done in the Bio copy:Anthrax is a caused by __________.a)protozoa b)bacteria c)some fungi d) virus Ans: b)bacteria Name a plant disease caused by fungi.Ans: Rust of WheatName 2 air borne and 2 water borne diseases.Ans: Refer to table in bullet points.Write a short paragraph on harms caused by microorganisms.Ans:Microorganisms called pathogens cause disease in humans, plants and animals. Pathogens enter a healthy body through air, water, contaminated food and infected person by direct or indirect contact or by the carrier. They cause diseases like cholera , typhoid, malaria etc in humans, Anthrax and Foot and mouth disease in cattle and plant diseases like Rust of wheat, yellow vein mosaic in okra etc. Microorganisms also grow on our food and cause food poisoning.?What is food poisoning?Ans: Refer to bullet points.End of Day – 2 ................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download