BackMicrobiology Exam 1 Study Guide: Step-by-Step Guidance
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Q1. Describe some of the destructive and beneficial actions of microbes. What is bioremediation?
Background
Topic: Microbial Roles in the Environment
This question tests your understanding of how microbes can both harm and help humans and the environment, as well as the concept of bioremediation.
Key Terms:
Destructive actions: Ways microbes cause disease, spoilage, or other harm.
Beneficial actions: Ways microbes contribute to health, industry, or the environment.
Bioremediation: The use of microbes to clean up pollutants.
Step-by-Step Guidance
List at least two ways microbes can be destructive (e.g., causing infectious diseases or food spoilage).
Identify at least two beneficial roles of microbes (e.g., nitrogen fixation, production of antibiotics, fermentation).
Define bioremediation and give an example of how microbes are used to remove environmental pollutants.
Try solving on your own before revealing the answer!
Final Answer:
Destructive actions of microbes include causing diseases in humans, animals, and plants (such as tuberculosis or crop blights), and spoiling food. Beneficial actions include decomposing organic matter, recycling nutrients, producing antibiotics, and aiding in digestion. Bioremediation is the use of microbes to clean up environmental pollutants, such as using bacteria to degrade oil spills or detoxify hazardous waste.
Q2. Recognize the system of scientific nomenclature that uses two names: a genus and a specific epithet.
Background
Topic: Scientific Nomenclature
This question is about the binomial system used to name organisms in biology.
Key Terms:
Genus: The first part of the scientific name, always capitalized.
Specific epithet: The second part, not capitalized.
Binomial nomenclature: The two-name system developed by Linnaeus.
Step-by-Step Guidance
Recall the rules for writing scientific names (italicized or underlined, genus capitalized, species lowercase).
Think of an example of a scientific name (e.g., Escherichia coli).
Identify which part is the genus and which is the specific epithet.
Try solving on your own before revealing the answer!
Final Answer:
The system is called binomial nomenclature. For example, in Escherichia coli, "Escherichia" is the genus and "coli" is the specific epithet. The genus is always capitalized, the specific epithet is lowercase, and both are italicized or underlined.
Q3. Which groups of microbes are prokaryotes? Which are eukaryotes?
Background
Topic: Classification of Microorganisms
This question tests your knowledge of the major groups of microbes and their cellular organization.
Key Terms:
Prokaryotes: Organisms without a nucleus (Bacteria, Archaea).
Eukaryotes: Organisms with a nucleus (Fungi, Protozoa, Algae, Helminths).
Step-by-Step Guidance
Recall the definition of prokaryote and eukaryote.
List the major groups of microbes (bacteria, archaea, fungi, protozoa, algae, viruses, helminths).
Classify each group as prokaryotic or eukaryotic.
Try solving on your own before revealing the answer!
Final Answer:
Bacteria and Archaea are prokaryotes. Fungi, protozoa, algae, and helminths are eukaryotes. Viruses are not classified as either because they are acellular.
Q4. What is the difference in photosynthesis and cellular respiration? Classify the organisms accordingly.
Background
Topic: Microbial Metabolism
This question tests your understanding of energy production in cells and which organisms perform each process.
Key Terms and Formulas:
Photosynthesis: Process by which light energy is converted to chemical energy.
Cellular respiration: Process by which cells break down glucose to produce ATP.
Step-by-Step Guidance
Define photosynthesis and cellular respiration, including their main reactants and products.
Identify which types of microbes (e.g., algae, cyanobacteria) perform photosynthesis.
Identify which types of microbes perform cellular respiration.
Try solving on your own before revealing the answer!
Final Answer:
Photosynthesis uses light energy to convert CO2 and H2O into glucose and O2. Cellular respiration breaks down glucose and O2 to produce ATP, CO2, and H2O. Algae and cyanobacteria perform photosynthesis; most bacteria, fungi, and protozoa perform cellular respiration.
Q5. What are the three domains? What 4 kingdoms are in the domain Eukarya?
Background
Topic: Taxonomy and Classification
This question is about the highest levels of biological classification.
Key Terms:
Domains: The broadest taxonomic categories (Bacteria, Archaea, Eukarya).
Kingdoms in Eukarya: Major groups within the domain Eukarya.
Step-by-Step Guidance
Recall the three domains of life.
List the four kingdoms within the domain Eukarya.
Try solving on your own before revealing the answer!
Final Answer:
The three domains are Bacteria, Archaea, and Eukarya. The four kingdoms in Eukarya are Protista, Fungi, Plantae, and Animalia.
Q6. Explain the importance of observations made by Hooke and van Leeuwenhoek. What is the Cell Theory?
Background
Topic: History of Microbiology
This question tests your knowledge of key historical figures and foundational concepts in cell biology.
Key Terms:
Hooke: First to observe cells in cork.
van Leeuwenhoek: First to observe living microorganisms.
Cell Theory: All living things are composed of cells.
Step-by-Step Guidance
Describe what Hooke observed and why it was significant.
Describe van Leeuwenhoek's contributions to microbiology.
State the main points of the Cell Theory.
Try solving on your own before revealing the answer!
Final Answer:
Hooke observed "cells" in cork, leading to the concept of the cell. van Leeuwenhoek was the first to observe living microbes, which he called "animalcules." The Cell Theory states that all living things are composed of cells, and cells are the basic unit of life.
Q7. Compare spontaneous generation and biogenesis.
Background
Topic: Origin of Life Theories
This question is about historical ideas regarding the origin of living organisms.
Key Terms:
Spontaneous generation: The idea that life can arise from nonliving matter.
Biogenesis: The idea that life arises only from preexisting life.
Step-by-Step Guidance
Define spontaneous generation and give an example of the belief.
Define biogenesis and explain how it differs from spontaneous generation.
Think of an experiment that helped disprove spontaneous generation.
Try solving on your own before revealing the answer!
Final Answer:
Spontaneous generation is the belief that living organisms can arise from nonliving matter, while biogenesis states that living things come only from other living things. Pasteur's experiments with swan-neck flasks supported biogenesis.
Q8. Summarize the Germ Theory of disease and know the scientist given credit for his contributing work.
Background
Topic: Microbial Causes of Disease
This question is about the theory that microorganisms cause disease and the scientists who contributed to this idea.
Key Terms:
Germ Theory: The idea that specific diseases are caused by specific microorganisms.
Key scientist: Louis Pasteur and Robert Koch.
Step-by-Step Guidance
State the main idea of the Germ Theory of disease.
Identify the scientist(s) most associated with this theory.
Recall one experiment or contribution made by these scientists.
Try solving on your own before revealing the answer!
Final Answer:
The Germ Theory states that microorganisms cause specific diseases. Louis Pasteur and Robert Koch are credited with key contributions; Koch developed postulates to link microbes to disease.
Q9. What is the importance and significance of Koch’s postulates and Pasteur’s work?
Background
Topic: Foundations of Microbiology
This question is about the experimental methods used to link microbes to disease and the impact of Pasteur's discoveries.
Key Terms:
Koch’s postulates: Criteria to establish a causative relationship between a microbe and a disease.
Pasteur’s work: Disproved spontaneous generation, developed vaccines, pasteurization.
Step-by-Step Guidance
List the main steps of Koch’s postulates.
Explain why these postulates are important for microbiology.
Describe at least one major contribution of Pasteur to science or medicine.
Try solving on your own before revealing the answer!
Final Answer:
Koch’s postulates provided a systematic way to link specific microbes to specific diseases, which was crucial for medical microbiology. Pasteur’s work led to the development of vaccines, pasteurization, and disproved spontaneous generation.
Q10. Identify the contributions to microbiology made by Ehrlich, Jenner, and Fleming. What was Ehrlich’s “magic bullet”?
Background
Topic: History of Antimicrobial Therapy and Immunology
This question is about key figures in the development of vaccines and antibiotics.
Key Terms:
Ehrlich: Developed the concept of a "magic bullet" drug.
Jenner: Developed the first vaccine (smallpox).
Fleming: Discovered penicillin.
Step-by-Step Guidance
Describe Jenner’s contribution to immunology.
Explain Ehrlich’s idea of a "magic bullet" and what disease it targeted.
Summarize Fleming’s discovery and its impact.
Try solving on your own before revealing the answer!
Final Answer:
Jenner developed the smallpox vaccine. Ehrlich’s "magic bullet" was Salvarsan, a drug to treat syphilis. Fleming discovered penicillin, the first antibiotic.
Q11. Describe important contributions of Golden Age and Modern Age scientists to Microbiology.
Background
Topic: Scientific Advances in Microbiology
This question asks you to summarize key discoveries and technological advances in microbiology from the late 1800s to the present.
Key Terms:
Golden Age: Period of rapid discovery (late 1800s–early 1900s).
Modern Age: Recent advances (molecular biology, genomics).
Step-by-Step Guidance
List at least two major discoveries from the Golden Age (e.g., vaccines, pure culture techniques).
Identify at least one modern technique or discovery (e.g., PCR, CRISPR, genomics).
Explain how these advances have impacted microbiology.
Try solving on your own before revealing the answer!
Final Answer:
Golden Age scientists developed vaccines, discovered the Germ Theory, and established pure culture techniques. Modern Age scientists have advanced molecular biology, developed PCR, and sequenced microbial genomes, greatly expanding our understanding of microbes.
Q12. Define bacteriology, mycology, parasitology, immunology, and virology.
Background
Topic: Branches of Microbiology
This question is about the different fields within microbiology.
Key Terms:
Bacteriology: Study of bacteria.
Mycology: Study of fungi.
Parasitology: Study of parasites.
Immunology: Study of the immune system.
Virology: Study of viruses.
Step-by-Step Guidance
Write a brief definition for each branch listed.
Think of an example organism or topic studied in each field.
Try solving on your own before revealing the answer!
Final Answer:
Bacteriology: study of bacteria; Mycology: study of fungi; Parasitology: study of parasites; Immunology: study of the immune system; Virology: study of viruses.
Q13. Differentiate normal and transient microbiota as they pertain to infectious disease. (Human microbiome)
Background
Topic: Human Microbiome
This question is about the types of microbes that live on and in the human body and their roles in health and disease.
Key Terms:
Normal microbiota: Microbes that are permanently present in the body.
Transient microbiota: Microbes that are present temporarily.
Step-by-Step Guidance
Define normal microbiota and give an example of their role in health.
Define transient microbiota and explain how they differ from normal microbiota.
Discuss how changes in these populations can affect disease risk.
Try solving on your own before revealing the answer!
Final Answer:
Normal microbiota are always present and help protect against pathogens. Transient microbiota are present for a short time and may be removed by competition or the immune system. Disruption of normal microbiota can increase susceptibility to infection.
Q14. What are opportunists and how do they function in the causation of disease? Define biofilm.
Background
Topic: Pathogenicity and Microbial Communities
This question is about microbes that cause disease under certain conditions and the structure of microbial communities.
Key Terms:
Opportunists: Microbes that cause disease when the host's defenses are compromised.
Biofilm: A community of microbes attached to a surface and embedded in a matrix.
Step-by-Step Guidance
Define opportunistic pathogens and give an example of when they might cause disease.
Explain what a biofilm is and why it is important in microbiology.
Try solving on your own before revealing the answer!
Final Answer:
Opportunists are microbes that cause disease when the immune system is weakened or normal microbiota are disrupted. A biofilm is a structured community of microbes attached to a surface, often resistant to antibiotics.
Q15. What is the difference in active and passive types of molecular movement across membranes?
Background
Topic: Cell Membrane Transport
This question is about how substances move across cell membranes.
Key Terms:
Active transport: Movement of molecules against a concentration gradient, requires energy.
Passive transport: Movement of molecules down a concentration gradient, does not require energy.
Step-by-Step Guidance
Define passive transport and give an example (e.g., diffusion, osmosis).
Define active transport and give an example (e.g., sodium-potassium pump).
Compare the energy requirements of each process.
Try solving on your own before revealing the answer!
Final Answer:
Passive transport does not require energy and moves substances down their concentration gradient. Active transport requires energy (usually ATP) to move substances against their gradient.
Q16. What is the difference in the terms hydrophilic and hydrophobic?
Background
Topic: Chemical Properties of Molecules
This question is about how molecules interact with water.
Key Terms:
Hydrophilic: Water-loving; dissolves in water.
Hydrophobic: Water-fearing; does not dissolve in water.
Step-by-Step Guidance
Define hydrophilic and hydrophobic.
Give an example of each type of molecule.
Explain why these properties are important for cell membranes.
Try solving on your own before revealing the answer!
Final Answer:
Hydrophilic substances interact well with water (e.g., salts, sugars), while hydrophobic substances do not (e.g., oils, lipids). This is important for the structure of cell membranes.
Q17. Know definition and importance of Prokaryotic and Eukaryotic structures discussed in exam chapters. Table 3.6
Background
Topic: Cell Structure
This question is about the differences between prokaryotic and eukaryotic cell structures and their functions.
Key Terms:
Prokaryotic structures: Cell wall, plasma membrane, nucleoid, ribosomes, flagella, pili.
Eukaryotic structures: Nucleus, mitochondria, endoplasmic reticulum, Golgi apparatus, lysosomes, cytoskeleton.
Step-by-Step Guidance
List at least three structures unique to prokaryotes and their functions.
List at least three structures unique to eukaryotes and their functions.
Explain why these differences are important for cell function and classification.
Try solving on your own before revealing the answer!
Final Answer:
Prokaryotes have a nucleoid, cell wall, and pili; eukaryotes have a nucleus, mitochondria, and endoplasmic reticulum. These differences affect how cells function and are classified.
Q18. Know and discuss Cell Wall and Cell Membrane structure/function and how it contributes to Gram Stain reactions.
Background
Topic: Bacterial Cell Structure and Staining
This question is about the differences in cell wall structure between Gram-positive and Gram-negative bacteria and how this affects staining.
Key Terms:
Cell wall: Provides shape and protection; made of peptidoglycan in bacteria.
Cell membrane: Controls movement of substances in and out of the cell.
Gram stain: Differential stain based on cell wall structure.
Step-by-Step Guidance
Describe the structure of the bacterial cell wall in Gram-positive and Gram-negative bacteria.
Explain how the Gram stain works and what it reveals about cell wall structure.
Discuss the role of the cell membrane in both types of bacteria.
Try solving on your own before revealing the answer!
Final Answer:
Gram-positive bacteria have thick peptidoglycan walls and retain crystal violet stain. Gram-negative bacteria have thin peptidoglycan and an outer membrane, so they do not retain the stain. The cell membrane is present in both and controls transport.
Q19. Know identifying characteristics of specific organisms discussed in class.
Background
Topic: Microbial Identification
This question is about recognizing key features of microbes covered in your course.
Key Terms:
Identifying characteristics: Morphology, staining, metabolism, genetic markers.
Step-by-Step Guidance
Recall the main features used to identify bacteria, fungi, viruses, etc.
Think of one or two examples of organisms and their unique characteristics.
Explain how these characteristics help in identification.
Try solving on your own before revealing the answer!
Final Answer:
Examples: Staphylococcus aureus is Gram-positive cocci in clusters; Escherichia coli is Gram-negative rods. These features help distinguish between species.
Q20. Know physical and chemical requirements for nutrition and growth of microorganisms.
Background
Topic: Microbial Nutrition and Growth
This question is about the environmental and nutritional factors that affect microbial growth.
Key Terms:
Physical requirements: Temperature, pH, osmotic pressure.
Chemical requirements: Carbon, nitrogen, sulfur, phosphorus, trace elements, oxygen.
Step-by-Step Guidance
List at least two physical factors that affect microbial growth.
List at least two chemical nutrients required by microbes.
Explain why these requirements are important for culturing microbes.
Try solving on your own before revealing the answer!
Final Answer:
Physical requirements include temperature and pH; chemical requirements include carbon and nitrogen. These factors must be controlled to grow microbes in the lab.
Q21. Know and discuss population growth of microbes and growth curves.
Background
Topic: Microbial Growth Dynamics
This question is about how microbial populations increase and the phases of growth in a closed system.
Key Terms and Formulas:
Growth curve: Lag, log, stationary, and death phases.
Generation time: Time required for a population to double.
Step-by-Step Guidance
Draw or describe the typical bacterial growth curve.
Define each phase of the growth curve.
Explain how generation time is calculated.
Try solving on your own before revealing the answer!
Final Answer:
The growth curve has four phases: lag (adaptation), log (exponential growth), stationary (nutrient depletion), and death (decline). Generation time is the time for the population to double during log phase.
Q22. Give a complete definition of a virus. Know each of the morphologies and give examples.
Background
Topic: Virology
This question is about the structure and classification of viruses.
Key Terms:
Virus: Acellular infectious agent with DNA or RNA, protein coat.
Morphologies: Helical, icosahedral, complex, enveloped, nonenveloped.
Step-by-Step Guidance
Define what a virus is and what it is made of.
List the main viral morphologies.
Give an example of a virus for each morphology.
Try solving on your own before revealing the answer!
Final Answer:
A virus is a nonliving, acellular particle with a nucleic acid core and protein coat. Morphologies: helical (tobacco mosaic virus), icosahedral (adenovirus), complex (bacteriophage), enveloped (influenza), nonenveloped (polio).
Q23. Differentiate a virus from a bacterium. (Know viral definition, size, structures). Define viral species.
Background
Topic: Viruses vs. Bacteria
This question is about the differences between viruses and bacteria in terms of structure, size, and classification.
Key Terms:
Virus: Acellular, smaller, needs host to replicate.
Bacterium: Cellular, larger, can reproduce independently.
Viral species: Group of viruses sharing genetic information and ecological niche.
Step-by-Step Guidance
List at least two structural differences between viruses and bacteria.
Compare their sizes.
Define what is meant by a viral species.
Try solving on your own before revealing the answer!
Final Answer:
Viruses are much smaller than bacteria, lack cellular structure, and require a host to replicate. Bacteria are cells with ribosomes and can reproduce on their own. A viral species is a group of viruses with similar genetic material and host range.
Q24. How are bacteriophage cultured? Describe the lytic vs lysogenic cycles of replication.
Background
Topic: Bacteriophage Biology
This question is about how viruses that infect bacteria are grown and their replication cycles.
Key Terms:
Bacteriophage: Virus that infects bacteria.
Lytic cycle: Virus replicates and lyses host cell.
Lysogenic cycle: Viral DNA integrates into host genome.
Step-by-Step Guidance
Describe how bacteriophage are cultured using bacterial lawns and plaques.
Outline the steps of the lytic cycle.
Outline the steps of the lysogenic cycle.
Try solving on your own before revealing the answer!
Final Answer:
Bacteriophage are cultured on bacterial lawns, forming plaques. The lytic cycle involves attachment, penetration, replication, assembly, and lysis. The lysogenic cycle involves integration of viral DNA into the host genome, where it can remain dormant.
Q25. What is cell culture and how does it apply to virology?
Background
Topic: Virus Cultivation
This question is about the use of cell cultures to grow and study viruses.
Key Terms:
Cell culture: Growing cells in vitro for research.
Virology: Study of viruses.
Step-by-Step Guidance
Define cell culture and its purpose.
Explain why viruses require living cells for growth.
Describe how cell cultures are used to study viral replication and effects.
Try solving on your own before revealing the answer!
Final Answer:
Cell culture is the growth of cells outside the organism. In virology, it allows viruses to be grown and studied, since viruses need living cells to replicate.
Q26. Compare bacteriophage to animal virus replication. What is cytopathic effect?
Background
Topic: Viral Replication
This question is about the similarities and differences in how viruses replicate in bacteria versus animal cells, and the effects on host cells.
Key Terms:
Bacteriophage: Virus infecting bacteria.
Animal virus: Virus infecting animal cells.
Cytopathic effect: Visible changes in host cells due to viral infection.
Step-by-Step Guidance
List the main steps of bacteriophage replication.
List the main steps of animal virus replication.
Define cytopathic effect and give an example.
Try solving on your own before revealing the answer!
Final Answer:
Bacteriophage inject DNA into bacteria; animal viruses enter by endocytosis or fusion. Both replicate and assemble new viruses, but animal viruses may cause cytopathic effects like cell lysis or syncytia formation.
Q27. Give examples of Oncogenic viruses. What is the Oncogenic Theory?
Background
Topic: Viruses and Cancer
This question is about viruses that can cause cancer and the theory behind it.
Key Terms:
Oncogenic virus: Virus that can cause cancer.
Oncogenic Theory: The idea that viruses can induce cancer.
Step-by-Step Guidance
List at least two examples of oncogenic viruses.
Define the Oncogenic Theory.
Explain how viruses can lead to cancer development.
Try solving on your own before revealing the answer!
Final Answer:
Examples: Human papillomavirus (HPV), Epstein-Barr virus (EBV). The Oncogenic Theory states that some viruses can cause cancer by integrating their genetic material into host cells and disrupting normal cell regulation.
Q28. Describe the multiplication cycle of a retrovirus—what is the enzyme used—give an example.
Background
Topic: Retroviruses
This question is about how retroviruses replicate and the key enzyme involved.
Key Terms:
Retrovirus: RNA virus that uses reverse transcription.
Reverse transcriptase: Enzyme that converts RNA to DNA.
Step-by-Step Guidance
Outline the steps of retrovirus replication (entry, reverse transcription, integration, transcription, assembly, release).
Name the enzyme responsible for reverse transcription.
Give an example of a retrovirus.
Try solving on your own before revealing the answer!
Final Answer:
Retroviruses enter the host cell, use reverse transcriptase to make DNA from RNA, integrate into the host genome, and produce new viruses. Example: HIV.
Q29. Know terminology: virus, virion, viroid, prion, plaques, prophage, diseases of DNA or RNA viruses
Background
Topic: Virology Terminology
This question is about key terms used in the study of viruses and related agents.
Key Terms:
Virus: Infectious agent with nucleic acid and protein coat.
Virion: Complete, infectious viral particle.
Viroid: Infectious RNA molecule without protein coat.
Prion: Infectious protein.
Plaques: Clear zones on a bacterial lawn due to virus infection.
Prophage: Phage DNA integrated into bacterial genome.
Step-by-Step Guidance
Define each term listed.
Give an example or disease associated with each, if possible.
Try solving on your own before revealing the answer!
Final Answer:
Virus: infectious agent; virion: complete virus particle; viroid: infectious RNA (plant diseases); prion: infectious protein (mad cow disease); plaques: clearings from virus lysis; prophage: integrated phage DNA; DNA virus disease: herpes; RNA virus disease: influenza.
Q30. Compare the structure/replication of an enveloped and a nonenveloped virus.
Background
Topic: Viral Structure and Replication
This question is about the differences between enveloped and nonenveloped viruses in terms of structure and how they enter/exit host cells.
Key Terms:
Enveloped virus: Has a lipid membrane around the capsid.
Nonenveloped virus: Lacks a lipid envelope.
Step-by-Step Guidance
Describe the structural differences between enveloped and nonenveloped viruses.
Explain how each type enters and exits host cells.
Give an example of each type.
Try solving on your own before revealing the answer!
Final Answer:
Enveloped viruses have a lipid membrane and often enter/exit by fusion or budding (e.g., influenza). Nonenveloped viruses lack this membrane and usually enter/exit by endocytosis or cell lysis (e.g., poliovirus).
Q31. Give reasons supporting viruses as non-living entities.
Background
Topic: Nature of Viruses
This question is about the debate over whether viruses are living or non-living.
Key Terms:
Non-living: Not capable of independent metabolism or reproduction.
Step-by-Step Guidance
List at least two characteristics of living things that viruses lack.
Explain why viruses are considered non-living by many scientists.
Try solving on your own before revealing the answer!
Final Answer:
Viruses are considered non-living because they cannot reproduce or carry out metabolism on their own; they require a host cell for both.
