Microorganisms: Viruses, Bacteria, and Fungi

Study Notes

Viruses

Consist of nucleic acid (DNA or RNA) enclosed in a protein coat
May have an outer envelope derived from the host cell membrane
Lack ribosomes, cell walls, and other cellular structures
Cannot replicate independently, requiring a host cell for reproduction

Bacteria

Single-celled organisms more complex than viruses
Diverse shapes: spherical, rod-shaped, filamentous, and comma-shaped
Possess a cell membrane, but lack a nucleus and mitochondria
Have a cell wall for protection and shape maintenance
Utilize oxygen for respiration
Reproduce asexually, often rapidly
Some bacteria are pathogenic, causing disease

Fungi

Diverse group of eukaryotic organisms including yeasts, molds, and mushrooms
Can be unicellular or multicellular
Have a defined nucleus and cell walls
Reproduce sexually or asexually
Can be parasitic, saprophytic (decomposers), or mutualistic (beneficial relationships)
Microscopic fungi can cause disease, while macroscopic fungi are often edible

Protozoa

Diverse group of single-celled eukaryotic organisms
Lack a cell wall
Reproduce sexually or asexually
Have a nucleus, cytoplasm, and various organelles
Utilize different locomotion mechanisms (e.g., cilia, flagella, pseudopodia)
Can exist in two forms: trophozoites (active, motile) and cysts (dormant, resistant)
Some protozoa can be pathogenic, causing disease

Description

Explore the fascinating world of microorganisms through this quiz that covers viruses, bacteria, and fungi. Learn about their structures, reproduction methods, and the roles they play in the ecosystem, including their impact on human health. Test your knowledge and understand the differences between these diverse organisms.