The big world of microorganisms

The big world of microorganisms, nitrogen cycle, what are microorganisms, types of microorganisms

1. The Big World Of

2. Topic At Glance… What are microorganisms??? Where are microorganisms found??? What are various groups of microorganisms??? How are microorganisms both beneficial and harmful to us??? How does food go bad??? What are the common methods of preserving food??? What is the role of various microorganisms in nitrogen cycle in nature???

3. What Are Microorganisms??? “ Microorganisms ” is derived from Greek words micros (small) and organismos (organisms). They are too small and can be seen with the help of microscope. Also called as microbes. They can be unicellular (single-celled) as well as multicellular (multi-celled). The study of microorganisms is known as microbiology.

4. Where Are They Present??? They are found everywhere– in water, in soil and in air. Dessert soil lack them because of hot and dry climate but found near roots of plants and dead leaves. They have heterotrophic mode of nutrition. Parasitic microorganism causing diseases in host are known as pathogens .

5. Types of microorganisms Bacteria Algae Protozoa Fungi

6. bacteria Simplest unicellular organisms. Exist singly or in chains or groups. A thick outer wall (spore) help them to survive in unfavourable conditions. Three types of bacteria: Bacillus (rod-shaped) Coccus (spherical-shaped) Spirillus (spiral-shaped)

7. algae Plant-like organisms having cell walls. Contains chlorophyll, therefore, can make food through photosynthesis. Autotrophs but lack roots, stem and leaves. They can be unicellular or multicellular. Seaweeds are largest algae. They are found in water bodies and moist places.

8. protozoa It means first animal. They are unicellular organisms. Exist in water and soil. They have various locomotory organs like pseudopodia, cilia and flagella. They digest their food in compartments called vacuoles .

9. Fungi They have saprophytic mode of nutrition. They obtain nutrients fro dead and decaying organic matter. Examples: Mushroom (Agaricus) Moulds (Rhizopus) Yeast (Unicellular Fungi)

10. virus Virus means poison in Latin. They can be helpful as well as harmful. They are the link between living and non-living. They are alive only when it enters cells of a living plant or animal energy of the host cell to remain alive.

11. Friendly Microorganisms Microorganisms play vital role in our lives. Ways in which they are beneficial to us: In decomposition and recycling In increasing soil fertility In food chains In food-making processes In water treatment plants In production of energy-giving fuels For making antibiotics For making vaccines In science and technological fields

12. Harmful microorganisms Microorganisms more than the harm the y cause to us than for their uses. Microorganisms causing diseases are called pathogens. They make their way into our body through the following ways: Through air Through food and water Through direct contact Through carriers Through cuts and wounds on skins

13. Food Preservation The process of treatment food to slow down or to stop the growth of microorganisms that spoil food is known as food preservation. Food spoilage by microorganisms is a disagreeable change in food. Common methods of food preservation: Using natural preservatives (salt) Using food grade chemical preservation (heating) By refrigeration and freezing (pasteurization) By drying and dehydration (canning)

14. Nitrogen cycle Nitrogen cycle is a cycle in which atmospheric nitrogen is converted from its gaseous form into usable form and returned to the atmosphere through stages that involves microorganisms.

15. Stages of nitrogen cycle Nitrogen fixation Nitrogen assimilation Ammonification Nitrification Denitrification

16. Overview

17. Thank You Made by: Rahul Chawla VIII B