Microorganisms: Friend and Foe | Class 8 Science Chapter 2 | Full Chapter

NCERT TUTORIAL 6,7 and 8・2 minutes read

Microorganisms are vital for various purposes, from food production to environmental balance, playing a crucial role in society. Understanding and utilizing microorganisms is crucial in harnessing their positive impacts on health and the environment.

Insights

  • Microorganisms, both beneficial and harmful, are ubiquitous in nature and play essential roles in various aspects of life, such as food production, disease transmission, and environmental balance.
  • Understanding the significance of microorganisms, from aiding in curd formation to soil fertility and disease prevention, underscores the importance of proper hygiene, vaccination, and food preservation techniques to harness their positive impact on society.

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Recent questions

  • What are microorganisms?

    Microorganisms are tiny organisms present in plants and animals, some invisible to the naked eye. They play essential roles in various aspects of life, including disease transmission and environmental balance.

  • How do microorganisms benefit society?

    Microorganisms are beneficial in various ways, from aiding in food production like curd and pickles to increasing soil fertility by decomposing waste. Understanding and utilizing them is vital for their positive impact on society.

  • What role do bacteria play in food production?

    Bacteria like Lactobacillus are crucial in the formation of food items like curd, pickles, and cheese. They aid in fermentation processes, breaking down substances to create new products.

  • How can communicable diseases be prevented?

    Proper hygiene practices, vaccination, and maintaining clean surroundings are essential in preventing the spread of communicable diseases like the common cold and chickenpox. Avoiding contact with contaminated food and water is crucial.

  • Why is it important to prevent mosquito breeding?

    Preventing mosquito breeding in stagnant water is crucial to curb diseases like malaria and dengue, as mosquitoes like the female Anopheles can spread these diseases. Keeping surroundings clean and dry helps prevent mosquito breeding and disease transmission.

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Summary

00:00

Microorganisms: Friends, Foes, and Benefits

  • Chapter Two of Class 8 discusses Microorganism Friends and Foes
  • Microorganisms are present in plants and animals, some of which are not visible to the naked eye
  • Black round structures visible under a magnifying glass are microorganisms
  • Microorganisms play a crucial role in various aspects of life, including disease transmission
  • Different diseases like polio, chicken pox, and malaria are caused by viruses and bacteria
  • Microorganisms are essential for various purposes, such as curd preparation and environmental cleaning
  • Microorganisms help in breaking down dead bodies and waste, aiding in soil fertility
  • Bacteria like Lactobacillus are crucial in the formation of curd
  • Microorganisms are beneficial in various ways, from health to environmental balance
  • Understanding and utilizing microorganisms is vital for their positive impact on society

25:53

Microorganisms in Food and Medicine

  • Lactobacillus is a light area that helps in the formation of bacteria, multiplying in milk to convert it into curd.
  • Milk consumed at dinner multiplies bacteria, aiding in the softening process of food items like China.
  • Bacteria play a crucial role in the making of food items like pickles and cheese.
  • Bhatura ingredients include Rava, Idli Group K, and a mix of warm water and small amounts of sugar.
  • Fermentation is essential for rice idli and dosa batter, aiding in the growth of microorganisms.
  • Carbon dioxide produced during respiration helps in the rapid growth of producers, increasing gas volume.
  • Beet is used in the banking industry for making bread, pastries, and cakes.
  • Natural sugar is found in wheat, rice, and fruit juices, contrasting with artificial sugar and color use.
  • Antibiotics, like penicillin, are made from microorganisms and help in stopping the growth of disease-causing microorganisms.
  • Vaccination introduces dead microorganisms into the body to produce suitable antibodies, aiding in fighting diseases effectively.

46:05

Microorganisms, Vaccination, and Disease Prevention

  • The body's fever-like feeling is due to the internal battle against microorganisms, leading to fatigue and the need for rest.
  • Turmeric aids in stabilizing the body's energy during illness, helping in recovery.
  • White blood cells fight against disease-causing bacteria and viruses to prevent frequent illnesses.
  • Vaccination is crucial in protecting against diseases like polio, ensuring children's health.
  • Microorganisms play a vital role in increasing soil fertility, with bacteria like rhizobium fixing nitrogen for plant growth.
  • Microorganisms aid in decomposing plant waste, converting it into nutrients for plant reuse.
  • Plastic waste does not decompose due to the lack of microorganisms, harming the environment.
  • Harmful microorganisms can spoil food and cause diseases, transmitted through contaminated water, food, and direct contact.
  • Communicable diseases spread through infected persons via air, water, food, and physical contact.
  • Proper hygiene and vaccination are essential in preventing the spread of communicable diseases like the common cold and chickenpox.

01:06:01

"Preventing Disease: Animals, Mosquitoes, and Food Preservation"

  • Animals and scents can act as barriers against disease-causing microbes.
  • Body transfer to contaminated food can lead to illness.
  • Mosquitoes, like the female Anopheles, can spread diseases like malaria.
  • Preventing mosquito breeding in stagnant water is crucial to curb diseases like malaria and dengue.
  • Keeping surroundings clean and dry is essential to prevent mosquito breeding.
  • Food poisoning can occur due to toxic substances produced by microorganisms in food.
  • Multivitamins should be taken with ample water to aid absorption.
  • Food preservation methods like using edible oils and salt can prevent food spoilage.
  • Preservatives are common chemicals used to inhibit the growth of microorganisms in food.
  • Salt and lemon are common preservatives used to preserve meat and fish.

01:26:00

Preventing Bacterial Growth in Food and Plants

  • Sugar in food increases bacterial growth
  • Boiling vinegar with oil prevents spoilage by inhibiting bacteria
  • Refrigeration at low temperatures prevents microbial growth in food
  • Pasteurization of milk eliminates harmful microbes, making it safe to consume
  • Dry fruits and vegetables are stored in sealed airtight packets to prevent microbial contamination
  • Nitrogen fixation by Rhizobium bacteria helps plants in fixing nitrogen, crucial for protein synthesis and plant growth
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