Microorganisms: Friend and Foe

Vocabulary flashcards about microorganisms, their types, uses, and effects.

Microorganisms (Microbes)

Living organisms around us which we normally cannot see.

Bacteria

A major group of microorganisms; examples include those involved in curd formation (Lactobacillus), disease-causing bacteria (typhoid, TB).

Fungi

A major group of microorganisms; examples include bread mould, Penicillium, Aspergillus.

Protozoa

A major group of microorganisms; examples include Amoeba and Paramecium; can cause diseases like dysentery and malaria.

Algae

A major group of microorganisms; examples include Chlamydomonas and Spirogyra; can be unicellular or multicellular.

Viruses

Microscopic entities that reproduce only inside the cells of a host organism (bacterium, plant, or animal); cause common ailments like cold, influenza, and serious diseases like polio and chicken pox.

Lactobacillus

A bacterium that promotes the formation of curd by multiplying in milk and converting it into curd.

Fermentation

The process of conversion of sugar into alcohol by yeast.

Antibiotics

Medicines that kill or stop the growth of disease-causing microorganisms; produced from bacteria and fungi (e.g., Streptomycin, tetracycline, erythromycin).

Vaccine

A preparation of dead or weakened microbes introduced into a healthy body to stimulate the production of antibodies and provide immunity against specific diseases.

Biological Nitrogen Fixers

Microbes, like certain bacteria, that fix nitrogen from the atmosphere to enrich soil with nitrogen, increasing its fertility.

Pathogens

Disease-causing microorganisms.

Communicable Diseases

Microbial diseases that can spread from an infected person to a healthy person through air, water, food, or physical contact (e.g., cholera, common cold, chicken pox, tuberculosis).

Carriers

Insects or animals that act as agents for transmitting disease-causing microbes (e.g., female Anopheles mosquito for malaria, housefly for various pathogens).

Preservatives

Substances such as salts and edible oils used to check the growth of microorganisms and preserve food.

Pasteurization

A process in which milk is heated to about 70°C for 15 to 30 seconds and then suddenly chilled and stored to prevent the growth of microbes.

Rhizobium

A bacterium that lives in the root nodules of leguminous plants and fixes atmospheric nitrogen.

Nitrogen Fixation

The process by which certain bacteria and blue-green algae convert atmospheric nitrogen into usable compounds.

Nitrogen Cycle

The process by which nitrogen is converted between its various chemical forms. This transformation can be carried out through both biological and physical processes.