Question

Write briefly on the occurrence of microorganisms.

Answer 1

Organisms are the forms of life that exist on Earth. Based upon various characteristics and their sizes they can be called microorganisms if they are small enough to be seen only through microscopes.

Complete Step by Step Answer:
Microorganisms or microbes are microscopic organisms that exist in the form of a single cell form or form a colony of cells.
Microorganisms are present practically everywhere - air, water, soil, foodstuff, sewage as well as inside the animal bodies. They are present in all the environmental conditions and ecosystems, from the great depths of the oceans to streams, snow of polar regions, hot springs, salty marshes, etc.
The maximum number of microbes however is found in the natural substrates that are rich in organic food materials and have suitable temperature and moisture for the growth and multiplication of the microbes.
Some microbes can even survive the extreme conditions of temperature, acidity, and dryness by forming a hard cyst which is an outer covering. When favourable conditions return, they germinate from the cyst and multiply. This process is also known as spore formation.
In favourable conditions, most microorganisms, multiply by vegetative reproduction which includes methods such as binary fission, budding, fragmentation, etc.

Note:
- These microorganisms can be prokaryotic or eukaryotic based on the presence or absence of membrane-bound cell organelles.
- Many diseases are caused by microorganisms. The microorganisms that cause diseases are called pathogens or pathogenic microbes.
- A specific group of bacteria is conditioned to survive and multiply in extreme conditions of temperature and pH too. They are called Archaebacteria. They include thermoacidophiles which can survive in extreme temperature and acidity and halophiles that can survive extreme alkalinity.