Questions and Answers
How do archaea differ from bacteria?
They have diverse cell wall compositions.
Prokaryotic cells do not have what?
A nucleus.
What does biogenesis refer to?
The development of life forms from preexisting forms.
What are the three domains of life?
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What happens to a bacterial cell when it is placed in a hypotonic solution?
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What is essential to disprove spontaneous generation in a liquid medium?
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Endospores allow a cell to survive environmental changes by producing a dormant period of no growth.
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Gram-positive cell walls maintain the shape of the cell and are sensitive to _____ and contain _____ acid.
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Salts and sugars work to preserve food by creating what kind of environment?
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At what stage in a normal growth curve do cells reach the maximum rate of cell division?
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What does the term 'aerotolerant anaerobe' refer to?
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What is an advantage of the direct microscope count?
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Who first practiced the use of phenol as a wound disinfectant?
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What kind of environment would a microorganism that does not have catalase or superoxide dismutase find difficult to live in?
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What are functions of the glycocalyx?
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Which scientist showed that anthrax was caused by the bacterium Bacillus anthracis?
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How do most bacteria reproduce?
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What are the short, numerous appendages used by some bacterial cells for adhering to surfaces called?
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What does the term 'amphitrichous' refer to?
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Which cellular structure protects bacteria from being phagocytized by white blood cells?
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What is the term for a spherical bacterial cellular shape?
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What are disease-causing microbes called?
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Which organelle most closely resembles a prokaryotic cell?
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Which group of microorganisms is most likely to spoil a freshwater trout preserved with salt?
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What is the role of conjugation in bacteria?
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What shape is the DNA found in most bacterial cells?
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Study Notes
Microbiology Exam 1 Key Concepts
- Archaea differ from bacteria due to varied cell wall compositions, allowing them to thrive in extreme environments.
- Prokaryotic cells lack a nucleus, distinguishing them from eukaryotic cells.
- Biogenesis describes the origin of life forms from existing life, countering the theory of spontaneous generation.
- The three-domain system classifies all life into Bacteria, Archaea, and Eukarya, reflecting evolutionary relationships.
- Bacterial cells placed in hypotonic solutions undergo osmotic lysis, causing the cell to swell as water enters.
- To disprove spontaneous generation in a liquid medium, using a sterile liquid and preventing microbial exposure is crucial.
- Endospores enable cells to enter a dormant state, allowing survival under harsh environmental conditions.
- Gram-positive cell walls are characterized by teichoic acids, maintain cell shape, and are sensitive to lysozymes and penicillin.
- Salts and sugars act as preservatives by creating hypertonic environments, drawing water out of microbial cells.
- The log phase of growth curves represents the period of maximal cell division rate.
- Aerotolerant anaerobes are organisms that do not utilize oxygen but can tolerate its presence.
- Direct microscope counts of microorganisms eliminate the need for incubation time, providing immediate results.
- Joseph Lister was the pioneer in using phenol as a disinfectant to prevent infections in surgical wounds.
- Microorganisms lacking catalase or superoxide dismutase struggle to survive in oxygen-rich environments due to oxidative damage.
- The glycocalyx serves multiple functions including biofilm formation, increasing virulence, protecting against dehydration, and aiding in binary fission.
- Robert Koch established that the bacterium Bacillus anthracis is the causative agent of anthrax, contributing to germ theory.
- Most bacteria reproduce through binary fission, a simple form of asexual reproduction.
- Fimbriae are short, hair-like structures on bacterial cells that assist in adhering to surfaces and forming biofilms.
- Amphitrichous describes bacteria that have flagella at both ends of their cellular surface, aiding in movement.
- Capsules are protective structures that prevent bacteria from being phagocytized by white blood cells, enhancing survival in the host.
- Cocci refer to spherical-shaped bacteria, while bacilli are rod-shaped and spirilla are spiral-shaped.
- Pathogens are microorganisms that can cause diseases in hosts.
- Chloroplasts resemble prokaryotic cells due to similarities in DNA structure and similarities in reproductive mechanisms.
- Facultative halophiles can tolerate high salt concentrations, making them likely responsible for spoiling salted freshwater fish like trout.
- Resistance to antibiotics like methicillin in gram-positive bacteria often arises through conjugation, a form of horizontal gene transfer.
- Most bacterial DNA is circular, differing from the linear DNA found in eukaryotic cells.
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Description
This quiz covers fundamental concepts from Microbiology Exam 1, including the differences between Archaea and Bacteria, prokaryotic versus eukaryotic cells, and key theories such as biogenesis. It also explores the implications of the three-domain system and the characteristics of bacterial cell walls.
