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Questions and Answers
Microbes are ___.
Microbes are ___.
diverse
All microbes cause disease.
All microbes cause disease.
False (B)
The human body contains __ body cells and ___ bacterial cells.
The human body contains __ body cells and ___ bacterial cells.
trillions of
The Human Microbiome Initiative was launched in 2016 to study microbes in ecosystems such as the human body.
The Human Microbiome Initiative was launched in 2016 to study microbes in ecosystems such as the human body.
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The system of (___) organisms in use today was developed in 1735 by Carolus Linnaeus.
The system of (___) organisms in use today was developed in 1735 by Carolus Linnaeus.
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___ are single-celled organisms that lack a nucleus.
___ are single-celled organisms that lack a nucleus.
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Which of the following are common cell shapes for bacteria? (Select all that apply.)
Which of the following are common cell shapes for bacteria? (Select all that apply.)
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Archaea are single-celled organisms that have a cell wall but it is not composed of ___.
Archaea are single-celled organisms that have a cell wall but it is not composed of ___.
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Archaea are often found in ___ environments.
Archaea are often found in ___ environments.
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Archaea are known to cause disease.
Archaea are known to cause disease.
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Fungi are ___ organisms.
Fungi are ___ organisms.
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Which of the following is a characteristic of fungi? (Select all that apply.)
Which of the following is a characteristic of fungi? (Select all that apply.)
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Protozoa are ___ organisms.
Protozoa are ___ organisms.
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Protozoa have a cell wall.
Protozoa have a cell wall.
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Many protozoa move through using ___ or cilia.
Many protozoa move through using ___ or cilia.
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Protozoa are always parasitic.
Protozoa are always parasitic.
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Algae are typically photosynthetic.
Algae are typically photosynthetic.
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Algae have a cell wall composed of ___.
Algae have a cell wall composed of ___.
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Viruses are cellular organisms.
Viruses are cellular organisms.
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Viruses reproduce by ___ their own cellular machinery.
Viruses reproduce by ___ their own cellular machinery.
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Viruses are often considered not alive.
Viruses are often considered not alive.
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The classification system used today for cellular organisms groups them into ___.
The classification system used today for cellular organisms groups them into ___.
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Archaea are genetically similar to bacteria.
Archaea are genetically similar to bacteria.
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Prokaryotes were the first organisms to appear on Earth.
Prokaryotes were the first organisms to appear on Earth.
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Microbes were the only life on Earth for a long period.
Microbes were the only life on Earth for a long period.
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___ is the theory that all organisms are composed of cells.
___ is the theory that all organisms are composed of cells.
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What was the name of the scientist who first observed cells using a microscope?
What was the name of the scientist who first observed cells using a microscope?
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The debate of spontaneous generation vs. ___ was central in the early days of microbiology.
The debate of spontaneous generation vs. ___ was central in the early days of microbiology.
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Spontaneous generation is the idea that life can arise from non-living matter.
Spontaneous generation is the idea that life can arise from non-living matter.
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Name the scientist who heated broth in flasks and found no microbes after sealing them.
Name the scientist who heated broth in flasks and found no microbes after sealing them.
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___ designed a flask with a curved neck that prevented microbes from entering, proving biogenesis.
___ designed a flask with a curved neck that prevented microbes from entering, proving biogenesis.
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The ___ theory of disease states that microbes cause infectious disease.
The ___ theory of disease states that microbes cause infectious disease.
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Which scientist contributed significantly to the Germ theory by investigating anthrax?
Which scientist contributed significantly to the Germ theory by investigating anthrax?
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Koch's postulates are a set of steps for linking a disease with the ___ responsible.
Koch's postulates are a set of steps for linking a disease with the ___ responsible.
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Koch's postulates are universally applicable to all pathogens.
Koch's postulates are universally applicable to all pathogens.
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___ is the process of introducing a weakened or inactive form of a pathogen to the body to stimulate an immune response.
___ is the process of introducing a weakened or inactive form of a pathogen to the body to stimulate an immune response.
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Who is credited with developing the first vaccine against smallpox?
Who is credited with developing the first vaccine against smallpox?
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The germ theory of disease was widely accepted before Jenner's work on vaccination.
The germ theory of disease was widely accepted before Jenner's work on vaccination.
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What was the name of the compound discovered by Alexander Fleming that inhibited bacterial growth?
What was the name of the compound discovered by Alexander Fleming that inhibited bacterial growth?
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Antibiotics are effective against all pathogens.
Antibiotics are effective against all pathogens.
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___ resistance is a growing concern because some bacteria have developed mutations that allow them to survive in the presence of antibiotics.
___ resistance is a growing concern because some bacteria have developed mutations that allow them to survive in the presence of antibiotics.
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The Genomics Era is characterized by studying microbes by reading their genomes, all the genes that make up the microbe.
The Genomics Era is characterized by studying microbes by reading their genomes, all the genes that make up the microbe.
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Similar genomes between microbes indicate a close evolutionary relationship.
Similar genomes between microbes indicate a close evolutionary relationship.
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Most microbes ___ cause disease.
Most microbes ___ cause disease.
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___ is the use of microorganisms to clean up environmental pollution.
___ is the use of microorganisms to clean up environmental pollution.
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___ is the study of how microorganisms interact with the environment.
___ is the study of how microorganisms interact with the environment.
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Bacillus thuringiensis (Bt) is a bacteria that produces a toxin harmful to insects.
Bacillus thuringiensis (Bt) is a bacteria that produces a toxin harmful to insects.
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A ___ is an organism that causes disease.
A ___ is an organism that causes disease.
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E. coli is a disease.
E. coli is a disease.
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COVID-19 is an infectious disease caused by the SARS-CoV-2 virus.
COVID-19 is an infectious disease caused by the SARS-CoV-2 virus.
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The ___ system helps combat pathogens and protect the body from disease.
The ___ system helps combat pathogens and protect the body from disease.
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Pathogens can subvert the immune system.
Pathogens can subvert the immune system.
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Some pathogens have been infecting humans for a very long time, causing diseases like malaria and ___.
Some pathogens have been infecting humans for a very long time, causing diseases like malaria and ___.
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New pathogens can emerge and cause new diseases.
New pathogens can emerge and cause new diseases.
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The ultimate goal of a pathogen is to ___ and ___.
The ultimate goal of a pathogen is to ___ and ___.
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Pathogens always cause symptoms that are beneficial to the host.
Pathogens always cause symptoms that are beneficial to the host.
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Pathogens can cause damage to the host by utilizing host resources.
Pathogens can cause damage to the host by utilizing host resources.
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Flashcards
Microbe
Microbe
A microorganism that requires a microscope to be seen, typically single-celled.
Human microbiota
Human microbiota
The collection of microorganisms living in and on the human body.
Types of Microorganisms
Types of Microorganisms
Microorganisms are classified into categories like bacteria, archaea, fungi, protozoa, algae, and viruses.
Prokaryotes
Prokaryotes
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Eukaryotes
Eukaryotes
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Antibiotics
Antibiotics
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Germ Theory of Disease
Germ Theory of Disease
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Koch's Postulates
Koch's Postulates
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Biogenesis
Biogenesis
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Spontaneous Generation
Spontaneous Generation
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Vaccination
Vaccination
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Bioremediation
Bioremediation
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Pathogen
Pathogen
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Antibiotic Resistance
Antibiotic Resistance
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Microbiome
Microbiome
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Cell Theory
Cell Theory
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Peptidoglycan
Peptidoglycan
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Methanogens
Methanogens
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Halophiles
Halophiles
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Thermophiles
Thermophiles
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Chitin
Chitin
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Swan-neck flask
Swan-neck flask
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Lactose
Lactose
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Biogeochemical cycling
Biogeochemical cycling
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E. coli
E. coli
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Photosynthesis
Photosynthesis
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Infectious Disease
Infectious Disease
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Mycelium
Mycelium
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Study Notes
Chapter 1: The Microbial World and You
- The study of microorganisms, their diversity, and their roles in human life and health.
- Includes the vast array of microbes: bacteria, archaea, fungi (yeast and molds), protozoa, algae and viruses (non-cellular).
- Microbes are incredibly diverse, some causing disease, and others playing essential roles in the environment, food production, and human welfare.
Outline
- Microbes in our lives
- Naming and classifying microbes
- A brief history of microbiology
- Microbes and human welfare
- Microbes and human disease
Microbes in Our Lives
- Microbes are single-celled organisms, invisible to the naked eye, requiring a microscope to be seen.
- Microbes are diverse and perform many functions.
- Some microbes cause disease, but most do not.
- Environmental microbes play vital roles (e.g., food chain, nutrient cycling, photosynthesis)
- Commercially useful microbes (e.g., chemical production, vitamins, fermented foods)
The Microbiome
- The human body contains many bacterial cells alongside body cells.
- Human microbiota refers to the bacteria in our intestines which aid in digestion and synthesize vitamins.
- Microbiota contribute to human health by preventing pathogenic bacteria colonization.
- Our bodies become populated by microbes at birth.
- The microbiome includes the microbes that interact with the human body.
Nomenclature
- The system used today for naming organisms was developed by Carolus Linnaeus in 1735.
- Each organism is assigned two names, italicized (underlined when written).
- The first name is capitalized, and the second is not, with abbreviations possible.
- Names may describe the organism, honor a researcher, or identify the habitat (e.g., Staphylococcus aureus).
Types of Microorganisms: Bacteria
- Bacteria are single-celled, prokaryotic organisms that lack a membrane-bound organelle containing DNA.
- Common shapes are spherical, rod-shaped, and spiral.
- Cells are surrounded by a cell wall containing chains of sugars (glycans) linked by amino acids (peptides).
- They reproduce asexually by binary fission, dividing into two equal cells.
Types of Microorganisms: Archaea
- Archaea are single-celled, prokaryotic organisms.
- Their cell walls differ from those of bacteria and are found in extreme environments.
- Examples include methanogens (methane producers), halophiles (salt-loving), and thermophiles (heat-loving).
- They don't cause disease commonly.
- They reproduce asexually.
Types of Microorganisms: Fungi
- Fungi are eukaryotes (DNA within a nuclear membrane).
- They can be unicellular (e.g., yeast) or multicellular (e.g., molds).
- Cell walls are composed of a polysaccharide called chitin.
- Fungi form multicellular structures (mycelia) which are networks of hyphae.
Types of Microorganisms: Protists
- Eukaryotes that lack cell walls, can move through using pseudopods, flagella, or cilia, and can be free-living or parasitic. (e.g., Protozoa).
Types of Microorganisms: Algae
- Eukaryotes with cell walls composed of cellulose (a type of polysaccharide).
- Require sunlight, carbon dioxide, and water to produce oxygen and carbohydrates.
Types of Microorganisms: Viruses
- Viruses are acellular (lack cellular structure), requiring electron microscopes.
- They are very small and simple, with a nucleic acid genome (either DNA or RNA) enclosed by a protein coat.
- Some have an optional lipid membrane (envelope).
- Viruses do not possess cellular machinery and are strictly parasitic (requiring host cells for reproduction)
Classification of Microorganisms
- Prior to the discovery of microbes, organisms were classified as plants or animals.
- In 1978, Carl Woese developed a classification system (now used)grouping all cellular organisms into three domains (Bacteria, Archaea, Eukarya).
- Bacteria and archaea are prokaryotes (lacking membrane-bound organelles) eukaryotes have them.
A Brief History of Microbiology
- Prokaryotes appeared on Earth before more complex lifeforms.
- For a long time, microbes were the only lifeforms on Earth.
- Early humans didn't recognize microbes.
- Advancements in technology were required to discover microbes.
The First Observations
- Robert Hooke (1665) used a microscope to view cells, the smallest structural unit of life, starting the cell theory.
- Late 17th century: scientists observed microbial cells ("animalcules") in various environments (rainwater, feces, dental plaque).
The Debate Over Spontaneous Generation
- After discovering microbes, scientists debated whether they arose spontaneously from nonliving matter or from pre-existing living cells (biogenesis).
The Theory of Biogenesis
- Scientists (including Louis Pasteur) performed experiments to demonstrate that microbes do not spontaneously generate, but instead emerge from pre-existing cells.
The Germ Theory of Disease
- For centuries, the cause of diseases remained unknown.
- Robert Koch (1876) developed the germ theory of disease, proposing that microbes cause infectious diseases.
- Koch's postulates established a set of criteria for linking specific microbes to specific diseases.
Vaccination
- Edward Jenner (late 18th century) developed the first vaccine against smallpox.
- Vaccination is based on the principle of inducing immunity against diseases using substances like vaccines.
- In his time the germ theory was not well accepted.
A Fortunate Accident – Antibiotics
- Alexander Fleming's accidental discovery of penicillin in 1928 led to the development of antibiotics, which treat bacterial infections, but resistance is a growing problem
Antibiotics
- Antibiotics have saved many lives, but some bacteria have evolved resistance to them (antibiotic resistance).
- Antibiotics generally work by targeting components of bacterial cells
The Genomics Era
- Scientists can now study microbes by "reading" their DNA (genomes).
- Techniques allow studying microbes without requiring them to be cultured, providing insights into their capabilities.
- Genome information allows understanding evolutionary relationships between microbes.
Microbes and Human Welfare
- Most microbes don't cause disease.
- Many microbes contribute to essential processes like nutrient recycling, helping with pest control, food production, and industrial technologies.
Biogeochemical Cycling
- Microbes play a vital role in converting chemical elements (e.g., nitrogen, carbon, oxygen) into forms useable by other organisms (for example, nitrogen fixation).
Bioremediation
- Microorganisms can help cleanup spills that involve oil and chemicals
Pest Control
- Some microbes produce toxins that specifically harm insects (without harming plants or other animals).
Microbes and Human Disease
- Disease is a condition disrupting normal body function, often caused by pathogens (disease-causing microbes).
- Pathogens aren't diseases themselves, but may cause diseases.
- Some diseases are caused by genetic factors, environmental factors or a combination of both.
- The body has defenses against pathogens.
- Some pathogens cause short-term or long-term diseases.
- Pathogens do not have diseases as their main goal. Survival and reproduction are the major goals.
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Description
Explore the fascinating study of microorganisms in Chapter 1, where you will learn about their diversity, roles in health, and impact on human welfare. Delve into the classifications of microbes, their importance in the environment, and their historical significance in microbiology. This quiz will test your knowledge on how microbes affect our daily lives.
