"The Role of Microorganisms in the Biosphere" PPT

"The Role of Microorganisms in the Biosphere" PPT

Part One Content: Learning Objectives:

Briefly describe what microorganisms are

List common types of microorganisms

Overview of the life of microorganisms and their role in the biosphere

Do you know what microorganisms are?

Microorganisms: In the biosphere, all lower organisms with tiny individuals and simple structures are collectively called microorganisms.

Types of microorganisms

Single-cell microorganisms: bacteria, actinomycetes, mycoplasma, chlamydia, rickettsiae, cyanobacteria, yeast, single-cell algae

Multicellular microorganisms: molds and macrofungi, etc.

Cell-free microorganisms: viruses, viroids, prions, etc.

The role of microorganisms in the biosphere PPT, part 2: Characteristics of microorganisms

1. Small individual

2. Simple structure

3. Wide variety

4. Widely distributed

Activity: Explore whether microorganisms exist around us

[Discover and ask questions] Bread that has been stored for a long time can easily become moldy; why does bread that has been stored for a long time become moldy?

[Collect relevant information] Bread becomes moldy mainly because some microorganisms (mainly mold) in the air enter the bread.

[Make a hypothesis] There are microorganisms everywhere around us.

[Design experimental plan] Use a controlled experiment, with one petri dish sealed and one petri dish opened (can be placed in classrooms, laboratories, homes, etc.)

[Implement the experiment and record] Each group leader led the students in their group to observe the growth of mold in the sterilized bread distributed by the teacher and recorded the observed phenomena in a timely manner.

[Analysis of experimental phenomena] Bacteria grew on the bread in the open petri dish, but there was no change in the sealed petri dish. In other words, the plaque was in the petri dish that was in contact with the air.

[Conclusion] There are microorganisms everywhere around us

The role of microorganisms in the biosphere PPT, Part 3: Types of microorganisms

saprophytic microorganisms

Concept: Microorganisms that can decompose organic matter in litter, animal carcasses and feces to obtain necessary materials and energy for life.

For example: Bacillus subtilis, lactic acid bacteria, mold, mushrooms among bacteria

Saprophytic microorganisms are the decomposers of ecosystems

The role of saprophytic microorganisms in the ecosystem can decompose complex organic matter into simple inorganic matter, and return the inorganic matter to the abiotic environment for reuse by green plants, which plays an irreplaceable role in the material cycle of the ecosystem.

parasitic microorganisms

Concept: Microorganisms that live in or on the bodies of other organisms and obtain the necessary materials and energy for life from these organisms.

For example: all viruses, some bacteria: Pneumococcus pneumoniae, Bacillus anthracis, fungal parasitism can cause ringworm and onychomycosis (all viruses, Pneumococcus pneumoniae, certain fungi)

The role of parasitic microorganisms in ecosystems: like animals, consumers

autotrophic microorganisms

Microorganisms that can use light energy or chemical energy to convert inorganic matter into energy-storing organic matter to meet their own needs for nutrients.

For example: cyanobacteria (use light for photosynthesis) sulfur bacteria, nitrifying bacteria (use chemical energy to synthesize carbon dioxide and water into organic matter)

The role of autotrophic microorganisms in ecosystems: like green plants, they are producers

Keywords: Beijing Normal University version of the eighth grade biology PPT courseware for the first volume is free to download, the role of microorganisms in the biosphere PPT download, .PPT format;

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