Microbiology Basics Quiz

Basic Characteristics

• Microorganisms, or microbes, are microscopic organisms too small to be seen with the naked eye, requiring a microscope for observation.
• They encompass a wide range of organisms, including bacteria, archaea, fungi, protozoa, algae, and viruses.
• Their size ranges from nanometers (viruses) to micrometers (bacteria and other microbes).

Cellular Structure

• Prokaryotic: Bacteria and archaea are prokaryotic, lacking a membrane-bound nucleus and other membrane-bound organelles.
• Eukaryotic: Fungi, protozoa, and algae are eukaryotic, possessing a nucleus and other membrane-bound organelles.
• Acellular: Viruses are acellular, lacking cellular structure; they are composed of genetic material (DNA or RNA) enclosed in a protein coat. The virus requires a host to replicate or reproduce.

Metabolism

• Microbes exhibit diverse metabolic strategies.
• Some are autotrophs, producing their own food from inorganic sources (like photosynthesis).
• Others are heterotrophs, obtaining energy and nutrients from organic sources.
• Some are chemoautotrophs, obtaining energy from chemical reactions with inorganic substances.

Reproduction

• Microbes typically reproduce asexually, through binary fission in bacteria, budding in yeast, or fragmentation.
• Some microbes can also reproduce sexually via conjugation, meiosis, and spore formation. This process facilitates genetic recombination and diversity.

Environmental Factors

• Microorganisms are found in a wide range of habitats, from extreme environments (e.g., hot springs, deep-sea vents) to more moderate environments (e.g., soil, water, and the human body).
• Their growth and activity are influenced by environmental factors, including temperature, pH, and nutrient availability.
• Some microorganisms can survive under extreme conditions, thriving in high temperatures, acidity/alkalinity, or high salinity.

Importance

• Microorganisms play critical roles in nutrient cycling, decomposition, and ecosystem functioning.
• They are essential for maintaining soil fertility, decomposing organic matter, and participating in biogeochemical cycles.
• Some microbes are pathogenic and cause diseases in humans and animals, while others are beneficial and used in various industrial processes such as food production, bioremediation, and genetic engineering.

Diversity

• Microorganisms display a broad diversity in morphology, physiology, and metabolic capabilities.
• This wide diversity enables microbes to occupy a variety of ecological niches and play important roles in various ecosystems.
• They can be identified by their unique characteristics such as cell shape, size, arrangement and staining properties.

Classification

• Microorganisms are categorized based on their evolutionary relationships and shared characteristics, often relying on molecular techniques.
• Phylogenetic trees are widely used in microbial classification.

Pathogenicity

• Some microorganisms cause diseases by producing toxins, invading tissues, or disrupting normal bodily functions.
• Pathogenicity varies significantly among different microbial species.
• Pathogens have specific traits that provide them with the capacity to cause disease.