STUDY GUIDE CHAPTER 1

flashcards covering basic concepts of microbiology, historical figures, branches, taxonomy, diversity, and beneficial microbial roles.

What is the difference between a microorganism and a microbiome, and how is the microbiome related to human health?

A microorganism is a microscopic organism. A microbiome is the community of microorganisms living in a particular environment (e.g., the human body). The microbiome influences human health through digestion, metabolism, immune function, and protection against pathogens.

Define an infectious disease.

A disease caused by pathogenic microorganisms that invade, multiply, and cause illness in a host.

Define an epidemic.

A widespread occurrence of an infectious disease within a community at a particular time.

Define an endemic.

A disease that is consistently present within a specific geographic area or population.

Define a pandemic.

An outbreak of a disease that occurs on a global scale across many countries.

Define normal flora.

Microorganisms that normally reside on or inside the human body without causing disease under normal conditions.

What is the difference between emerging and reemerging infectious diseases?

Emerging diseases are newly appearing or newly recognized in a population; reemerging diseases are known diseases that have increased in incidence or geographic range after a period of control.

Measles causative organism?

Measles virus (a paramyxovirus).

Measles mode of transmission.

Airborne droplets; highly contagious.

Influenza causative organism?

Influenza virus (types A, B, and C).

Influenza mode of transmission.

Respiratory droplets and contact; aerosols may contribute.

Pertussis causative organism?

Bordetella pertussis.

Pertussis mode of transmission.

Airborne droplets and close contact, especially during coughing.

MRSA causative organism.

Methicillin-resistant Staphylococcus aureus (a strain of Staphylococcus aureus).

Lyme disease causative organism?

Borrelia burgdorferi (a spirochete).

Lyme disease mode of transmission.

Tick bite, typically by Ixodes ticks.

Anton van Leeuwenhoek contributed which foundational work?

First to observe and describe microorganisms with microscopes; often called the father of microbiology.

Robert Hooke contributed which foundational work?

Described the structure of cork and coined the term ‘cell’; helped advance microscopy.

Holmes and Semmelweis contributed which important idea?

Advocated handwashing and antiseptic techniques to prevent puerperal fever and other infections in clinical settings.

Carl Linnaeus contributed which key concept?

Developed binomial nomenclature for naming organisms (genus and species).

Louis Pasteur contributed which key concepts?

Germ theory of disease; pasteurization; contributions to vaccines and fermentation.

Robert Koch contributed which key concept?

Koch's postulates linking specific pathogens to specific diseases.

Joseph Lister contributed which key concept?

Antiseptic principles in surgery; use of antiseptics to reduce infections.

Paul Ehrlich contributed which key concept?

Concept of chemotherapy and the idea of a “magic bullet”; developed Salvarsan for syphilis and advanced staining techniques.

Alexander Fleming contributed which key discovery?

Discovered penicillin, the first true antibiotic, leading to the antibiotic era.

Edward Jenner contributed which landmark advancement?

Developed the smallpox vaccine using cowpox, the first successful vaccine.

Define Immunology.

The branch of biology that studies the immune system and immune responses.

Define Virology.

The study of viruses and virus-related diseases.

Define Clinical microbiology.

The branch focused on diagnosis and management of infectious diseases in clinical settings, including laboratory identification of pathogens.

Define Mycology.

The study of fungi, including yeasts and molds.

Define Industrial microbiology.

The application of microorganisms in industrial processes, such as fermentation and production of enzymes, pharmaceuticals, and biofuels.

Define Recombinant DNA technology.

Genetic engineering technique that combines DNA from different sources to create new genetic combinations.

What is the system of naming organisms established by Linnaeus?

Binomial nomenclature (genus and species) used to name organisms.

What are the two parts of a binomial name and what do they represent?

Genus (first part) and species (second part); together they uniquely identify an organism.

Give an example of a binomial name.

Escherichia coli or Homo sapiens (genus capitalized, species lowercase; both italicized in print).

What are the three domains in the three-domain system?

Bacteria, Archaea, and Eukarya.

Name the traditional four-kingdom classification system often contrasted with the three-domain system.

Monera, Protista, Fungi, and Metazoa (Animalia).

List the six major types of microorganisms.

Bacteria, Archaea, Fungi, Protozoa, Algae, and Viruses.

Are microorganisms typically unicellular or multicellular?

Most are unicellular; some fungi and certain algae are multicellular.

Are microorganisms prokaryotic or eukaryotic?

Bacteria and Archaea are prokaryotic; Fungi, Protozoa, and Algae are eukaryotic; viruses are acellular.

What are the main nutritional modes of microorganisms?

Autotrophs (self-feeders) and Heterotrophs (depend on others for carbon source).

Name common modes of locomotion used by microorganisms.

Flagella, cilia, and amoeboid movement; some are nonmotile.

Give common modes of reproduction in microorganisms.

Binary fission (most bacteria), budding, spore formation (fungi and some bacteria), and sexual reproduction in some protozoa and fungi; viruses replicate within host cells.

Name a beneficial role of microorganisms in the food chain.

They contribute to the food chain by decomposing organic matter and forming bases for nutrient cycles.

Which cycles involve microbial recycling of elements in soil, water, and air?

Nitrogen cycle, carbon cycle, and oxygen cycle.

What is one key product of photosynthesis involving microorganisms?

Conversion of light energy into chemical energy; microorganisms (like cyanobacteria and algae) contribute to photosynthesis.

What vitamins are synthesized by some microorganisms that benefit humans?

Vitamin K and B vitamins (e.g., B12 in some gut microbiota contexts).

Name an important commercial application of microorganisms.

Synthesis of chemical products (e.g., enzymes, organic acids), production of fermented foods, sewage treatment, bioremediation (cleanup of toxic dumps), and pest control.

Give an example of a microbial role in the food industry.

Fermentation processes producing beverages, yogurt, cheese, and other foods.

How do microorganisms contribute to sewage treatment?

They break down organic waste, reducing Biological Oxygen Demand and helping purify wastewater.

How can microorganisms aid in bioremediation of toxic dumps?

They metabolize and detoxify pollutants, helping to clean contaminated environments.

How are microorganisms used in insect pest control?

Certain microbes are used as biological control agents to target pests (e.g., Bacillus thuringiensis).