This title slide is titled "Microorganisms: Friend and Foe." Its subtitle describes discovering the beneficial and harmful roles of tiny organisms in our world.

Microorganisms: Friend and Foe

Discovering beneficial and harmful roles of tiny organisms in our world

Source: Class 8 Science Chapter 2

The presentation agenda introduces microorganisms and their types, followed by their beneficial uses in nitrogen fixation, food preservation, and industry. It then covers harmful effects and diseases, concluding with prevention strategies and key takeaways.

Presentation Agenda

1. Introduction to Microorganisms and Types

Overview of microorganisms, their types, and basic characteristics.

2. Beneficial Uses of Microorganisms

Nitrogen fixation, food preservation, and industrial applications.

3. Harmful Effects and Diseases

Diseases caused by harmful microorganisms and their impacts.

4. Prevention Methods and Conclusion

Strategies for prevention and key takeaways from the presentation. Source: Class 8 Science, Chapter 2: 'Microorganisms: Friend and Foe'

This section header slide, numbered 02, is titled "What are Microorganisms?" Its subtitle describes them as tiny living things invisible to the naked eye, found everywhere in air, water, and soil.

What are Microorganisms?

02

What are Microorganisms?

Tiny living things invisible to the naked eye, found everywhere in air, water, soil.

Source: Class 8 Science - Chapter 2

The slide "Types of Microorganisms" lists five main categories: bacteria, fungi, protozoa, algae, and viruses. It describes bacteria as single-celled prokaryotes, fungi as yeasts (unicellular) and molds (multicellular), protozoa as unicellular eukaryotes like amoeba, algae as photosynthetic organisms, and viruses as non-living acellular agents.

Types of Microorganisms

• Bacteria: Single-celled prokaryotic microorganisms.
• Fungi: Yeasts (unicellular) and molds (multicellular).
• Protozoa: Unicellular eukaryotes like amoeba.
• Algae: Photosynthetic organisms such as green algae.
• Viruses: Non-living, acellular infectious agents.

The slide "Microorganisms Everywhere" showcases microbes in everyday settings through images. Examples include yeast fermenting yogurt, protozoa in pond water, bacteria in garden soil, fungi on decaying fruits, and Lactobacillus in curd milk.

Microorganisms Everywhere

!Image

• Yeast fermenting yogurt for probiotics
• Protozoa visible in pond water samples
• Bacteria abundant in garden soil
• Fungi growing on decaying fruits
• Lactobacillus cultures in curd milk

Source: Image from Wikipedia article "Microorganism"

This slide serves as the section header for Section 05: Beneficial Microorganisms. It portrays them as helpful allies in nature, food production, and industry, exemplified by Lactobacillus in curd.

Beneficial Microorganisms

05

Beneficial Microorganisms

Friends helping in nature, food production, and industry. Example: Lactobacillus in curd.

Source: Class 8 Science, Chapter 2

Rhizobium bacteria fix atmospheric N₂ in legumes by forming symbiotic nodules on plant roots. This naturally boosts soil fertility and crop yields eco-friendly, with examples like soybeans, peas, and clover.

Nitrogen Fixation

• Rhizobium bacteria fix atmospheric N₂ in legumes
• Forms symbiotic nodules on plant roots
• Increases soil fertility naturally
• Examples: soybeans, peas, clover
• Boosts crop yields eco-friendly

Source: Class 8 Science, Chapter 2

Food preservation via fermentation uses yeast to produce bread and beer from sugars, lactic acid bacteria to make yogurt, cheese, and sauerkraut from milk and cabbage, and Acetobacter to create vinegar from alcohol. These processes also generate probiotics that benefit gut health.

Food Preservation

• Yeast ferments sugars to produce bread and beer.
• Lactic acid bacteria turn milk into yogurt and cheese.
• Acetobacter converts alcohol into vinegar.
• Lactic acid bacteria ferment cabbage into sauerkraut.
• Probiotics from fermentation benefit gut health.

Source: Class 8 Science Chapter 2

Industrial Applications showcases microbial biotech products like penicillin antibiotics from Penicillium fungus, detergent enzymes from bacteria, and insulin from genetically modified bacteria. It also covers biofuels from algae and wastewater treatment using microbes.

Industrial Applications

• Antibiotics like penicillin from Penicillium fungus
• Enzymes in detergents from bacteria
• Biofuels produced from algae
• Insulin via genetically modified bacteria
• Wastewater treatment using microbes

Source: Factory microbes image

Section 09 introduces "Harmful Microorganisms" as a key topic. The subtitle describes them as foes causing diseases and food spoilage, including pathogenic bacteria, viruses, fungi, and protozoa.

Harmful Microorganisms

09

Harmful Microorganisms

Foes causing diseases, food spoilage: pathogenic bacteria, viruses, fungi, protozoa

Source: Class 8 Science, Chapter 2: Microorganisms: Friend and Foe

The slide contrasts beneficial microorganisms ("Friends") that aid in yogurt and cheese production, penicillin medicine, nitrogen fixation, and bread rising. It opposes them with harmful ones ("Foes") causing diseases like cholera, tetanus, tuberculosis, typhoid, and malaria.

Beneficial vs Harmful

| • Yogurt: Lactic acid bacteria ferment milk into curd.

• Medicine: Penicillin antibiotic from Penicillium fungus.
• Nitrogen fixation: Rhizobium bacteria enrich soil.
• Bread making: Yeast produces CO2 for rising.
• Cheese: Bacteria help curdle and ripen milk. | • Cholera: Vibrio cholerae causes severe diarrhea.
• Tetanus: Clostridium tetani leads to muscle spasms.
• Tuberculosis: Mycobacterium tuberculosis infects lungs.
• Typhoid: Salmonella typhi causes high fever.
• Malaria: Plasmodium parasite transmitted by mosquitoes. |

Source: Class 8 Science, Chapter 2: Microorganisms: Friend and Foe

This slide outlines diseases caused by microbes, with bacteria causing typhoid, cholera, and food poisoning, while viruses cause COVID-19 and flu. Protozoa cause malaria, and fungi cause ringworm.

Diseases Caused by Microbes

• Bacteria cause typhoid and cholera.
• Viruses cause COVID-19 and flu.
• Protozoa cause malaria.
• Fungi cause ringworm.
• Bacteria cause food poisoning.

Source: Class 8 Science, Chapter 2: Microorganisms: Friend and Foe

This timeline outlines the spread of infectious diseases through four stages: exposure via air/water/contact, incubation with symptomless pathogen multiplication, symptom onset (e.g., fever, cough), and transmission to others (e.g., droplets, blood). Prevention breaks the chain via vaccination, hygiene, and protective measures.

Spread of Infectious Diseases

Stage 1: Exposure: Contact with Pathogen Infectious agent enters body via air, water, food, or direct contact. Stage 2: Incubation: Microbes Multiply Inside No symptoms shown; pathogens reproduce rapidly over days or weeks. Stage 3: Symptoms: Disease Signs Appear Fever, cough, fatigue emerge; e.g., TB causes persistent bloody cough. Stage 4: Transmission: Spread to Others Infected person transmits via droplets or fluids, e.g., AIDS through blood. Prevention Steps: Break the Chain Vaccinate, maintain hygiene, use protection to halt disease spread.

Source: Class 8 Science - Microorganisms

The slide on Prevention of Microbial Diseases lists key strategies like vaccination, clean water, hygiene, and pasteurization to stop infections. It also highlights judicious antibiotics against resistant pathogens and a balanced diet to boost immunity.

Prevention of Microbial Diseases

• Vaccination prevents viral and bacterial diseases.
• Clean water and hygiene reduce infections.
• Pasteurization kills microbes in milk and food.
• Judicious antibiotics combat resistant pathogens.
• Balanced diet boosts immunity against microbes.

Source: Hygiene practices image

The conclusion slide emphasizes balancing the benefits and risks of microorganisms, noting they are essential to life, with key phrases like "Balance is Key!" It ends with a thank you, Q&A invitation, and a subtitle encouraging questions and discussion.

Microorganisms: Friends & Foes

• Balance benefits & risks

• Microbes essential to life
• Thank you!
• Q&A
• Balance is Key!

Questions? Let's discuss!

Source: Class 8 Science, Chapter 2