Microbiology Quiz: Fungi, Bacteria, and Viruses

Introduction to Microbiology

• Microbiology is the study of very small living things, too small to be seen without magnification.
• Microorganisms, also called microbes, include bacteria, viruses, fungi, and protozoa.
• Not all microbes cause disease; many are useful or essential for life.

Scope of Microbiology

• Microorganisms are crucial for various processes on Earth, including nutrient cycling.
• They play a role in the environment, human health, and the economy.
• Microbes participate in biodegradation/biodeterioration, biotechnology, and various industrial processes, including the production of medicines, biofuels, and food.
• Microbes are present in soil, water, plants, animals, radioactive waste, deep in the earth's crust, arctic ice, and glaciers.

Harmful Microorganisms

• Some microbes are harmful, causing diseases in humans, cattle, and crops.
• Examples include bacteria (pneumonia, dysentery, diphtheria, plague, meningitis), viruses (chickenpox, measles, mumps, colds, warts), protozoa (amoebic dysentery, malaria), and fungi (ringworm, athlete's foot).

Useful Microorganisms

• Bacteria and fungi act as decomposers, breaking down organic matter and releasing nutrients.
• Microbes are essential in nutrient cycling, soil formation, and various industrial processes.
• Yeast is used in bread-making, brewing, and yoghurt production.

Branches of Microbiology

• Bacteriology: study of bacteria
• Mycology: study of fungi
• Phycology: study of algae
• Protozoology: study of protozoa
• Virology: study of viruses
• Parasitology: study of parasites (including protozoa and worms)
• Nematology: study of nematodes

Origin and Evolution of Microorganisms

• Phylogeny shows the degree of relatedness among living things.
• Evolution leads to changes in structural and functional characteristics over generations.
• All new species are derived from pre-existing ones.
• Evolutionary relationships are often represented using phylogenetic trees.

The Classification of Microorganisms

• Before the discovery of microbes, all organisms were categorized as either plants or animals.
• Carl Woese created a new system based on cell structure categorizing organisms into three domains:
  • Bacteria
  • Archaea
  • Eukarya
    • Protists (slime molds, protozoa, algae)
    • Fungi (yeasts, molds, mushrooms)
    • Plants (mosses, ferns, and flowering plants)
    • Animals (sponges, worms, insects, vertebrates)

A Brief History of Microbiology

• Anton van Leeuwenhoek was the first to observe microorganisms in 1673, marking the beginning of microbiology.
• Robert Hooke in 1665 described the structures of cells.
• Spontaneous generation was once believed but debunked by experimentations by Francesco Redi and Lous Pasteur (1729–1799)
• Louis Pasteur disproved spontaneous generation in the 1860s, proposing the germ theory of disease, showing microbes cause disease.
• Robert Koch identified the first bacterial pathogens, Bacillus anthracis (anthrax) and Mycobacterium tuberculosis (tuberculosis), introducing Koch's Postulates to identify pathogens.

The Golden Age of Microbiology

• The period from 1857 to 1914 was a period of rapid advances in microbiology.
• Discoveries included identifying microbial agents of diseases and studying immunity, improving microscopy and culturing organisms, and developing vaccines and surgical techniques.

Other Landmarks in Microbiology

• First identification of viruses (tobacco mosaic virus)
• Development of synthetic antimicrobial chemicals; first antibiotic discovery(Penicillin)
• Discoveries of prions.

Ecological Roles of Microbes

• Microbes play vital roles in ecosystems, including nitrogen fixation, photosynthesis, and decomposition.
• Nitrogen fixation converts atmospheric nitrogen into usable forms.
• Photosynthetic microbes support aquatic food webs.
• Decomposers recycle nutrients.

Microbes & Humanity

• Microbes play a significant role in providing health benefits.
• They also play an essential role in food production, and contribute to pollution control.
• Although very few microbes cause diseases, they impact human health and life on Earth.

Cellular Organization

• Organisms are categorized based on their cellular structures:
  • Eukaryotic organisms have a nucleus and membrane-bound organelles (e.g., animals, plants, fungi, protists).
  • Prokaryotic organisms lack a nucleus and membrane-bound organelles (e.g., bacteria, archaea).

Types of Microorganisms Based on Acquiring Nutrition

• Autotrophic organisms produce their own food (e.g., plants and some bacteria).
• Heterotrophic organisms obtain nutrients by consuming other organisms (e.g., humans).
• Saprophytic organisms consume decaying organic matter (e.g., fungi).

Why Microbiology Is Important to Nurses

• Microbiology is vital in nursing.
• Nurses must understand microbes to prevent and treat infectious diseases.
• Knowledge of microbes helps nurses in administering antibiotics, collecting specimens, educating patients, and developing appropriate care plans.

Assigning Specific Names

• A system of nomenclature, called binomial nomenclature, is used to assign scientific names to organisms.
• Each name consists of genus and species names; the genus name comes first and is capitalized while the species name comes last and is lowercase.
• Both should be italicized and written in Latin.