Microbiology Test Questions Flashcards

Questions and Answers

Which of the following is a prokaryotic domain in the three-domain system?

Fungi

Animalia

Eukarya

Bacteria (correct)

Which of the following could be used to sterilize plastic petri plates in a brown paper bag?

Microwaves

Sunlight

Gamma radiation (correct)

Ultraviolet radiation

None of the above

Which of the following is probably true about all the experiments that supposedly proved spontaneous generation?

The food source could not support life

Microorganisms were already present

Too much heat was applied

Air was lacking

All of the above (correct)

The endosymbiotic theory hypothesizes that?

Eukaryotic cells evolved from prokaryotic cells Signup and view all the answers

Which of the following eukaryotic organelles most closely resembles a prokaryotic cell?

Mitochondrion Signup and view all the answers

What is an agent of selection in the evolution of resistance?

Antibiotics Signup and view all the answers

Which of the words is used to describe the sum total of DNA in a cell?

Genome Signup and view all the answers

To select for streptomycin-resistant bacteria, cells should be grown on media?

Containing streptomycin, but lacking other antibiotics Signup and view all the answers

The DNA transfer from a donor cell to a recipient cell during cell contact is called?

Conjugation Signup and view all the answers

Vertical gene transfer occurs when genes are passed?

From parent to offspring Signup and view all the answers

Mutations are usually beneficial.

False Signup and view all the answers

For the evolution of resistance, which of these are required?

Mutation and selection Signup and view all the answers

Which of these is not a step in PCR?

mRNA is copied to form DNA Signup and view all the answers

Which of these recognizes and cuts specific DNA sequences?

Restriction enzymes Signup and view all the answers

One advantage of cDNA libraries over genomic libraries is that the cDNA library?

Lacks intron sequences Signup and view all the answers

In the blue-white screening procedure, the purpose of including X-gal in the culture medium is to?

Distinguish between recombinant and non-recombinant plasmids Signup and view all the answers

Collections of clones containing random DNA fragments from a whole genome are called?

Genomic libraries Signup and view all the answers

The DNA polymerase enzyme, which is produced by a heat-tolerant bacterium, is used in?

Polymerase chain reaction Signup and view all the answers

Which of the following is a eukaryotic domain in the three-domain system?

Eukarya Signup and view all the answers

Who was the first to observe microorganisms with a microscope?

van Leeuwenhoek Signup and view all the answers

These are the primary molecules making up membranes in cells:

Phospholipids Signup and view all the answers

Aerobic respiration differs from anaerobic respiration in which of the following respects?

The final electron acceptors are different Signup and view all the answers

Which of the following has to consume carbohydrates for both carbon and energy?

Chemoheterotroph Signup and view all the answers

Salts and sugars work to preserve foods by creating a

Hypertonic environment Signup and view all the answers

The term facultative anaerobe refers to an organism

Can use oxygen or can grow without oxygen Signup and view all the answers

Which group of the following bacterial growth types and temperatures is mismatched?

Thermophile - optimal growth 37°C Signup and view all the answers

Which group of microorganisms is most likely to spoil a freshwater trout preserved with salt?

Psychrophiles Signup and view all the answers

Which of the following is a good method to sterilize the interior of dense materials without using high heat?

Ionizing radiation Signup and view all the answers

One important ecosystem function performed by microorganisms (such as algae and cyanobacteria) is the primary production of biomass through the metabolic process of

Photosynthesis Signup and view all the answers

The bacteria that are typically present and on the surface of the human body, and which are typically harmless or even helpful to humans are called the '________' microbiota.

normal Signup and view all the answers

What does the scientific debate about spontaneous generation vs. biogenesis tell us about the process of science?

Science is the process of refining ideas through vigorous debate and the challenging of old ideas with new data collection Signup and view all the answers

Which of the following bacterial genus names means 'string of rod-shaped cells'?

Streptobacillus Signup and view all the answers

Regarding Pasteur's experiments with the S-neck flask, which of the following statements is true?

The S-flask allowed air to enter the flask Signup and view all the answers

Whose work began the 'golden age of microbiology' and included the refinement of aseptic technique?

Pasteur Signup and view all the answers

A single celled, eukaryotic, motile organism that ingests its food and has no cell wall is a

Protozoan Signup and view all the answers

A prokaryote that lacks peptidoglycan in its cell walls and typically lives in extreme environments is called a

Archaean Signup and view all the answers

What is the typical diameter of bacterial cells?

0.2-8 microns Signup and view all the answers

In the name Escherichia coli, Escherichia is the

Genus Signup and view all the answers

One way in which fungi and algae differ from bacteria is that bacteria

Do not have a membrane bound nucleus Signup and view all the answers

What is the primary function of the bacterial cell wall?

To protect the cell, especially by preventing osmotic lysis Signup and view all the answers

What type of bacterium has an extra membrane layer on the outside of the cell wall, which dissolves in alcohol, leaving holes in the peptidoglycan layer and allowing crystal violet-iodine to wash out?

Gram-negative Signup and view all the answers

What is the function of eukaryotic cilia and flagella?

Movement Signup and view all the answers

If a pharmaceutical drug attacks and destroys peptidoglycan, which type of microorganism would it kill?

Bacteria Signup and view all the answers

If a pharmaceutical drug attacks and destroys chitin, would you expect it to have a significant side effect on humans?

No Signup and view all the answers

Mitochondria are the sites of _________ in eukaryotic cells.

cellular respiration Signup and view all the answers

Which type of molecule is composed of (CH2O) units?

Carbohydrates Signup and view all the answers

Enzymes are a type of __________ composed of a string of amino acids.

Protein Signup and view all the answers

Which type of reaction absorbs (requires) energy when it occurs?

Anabolic (synthesis) Signup and view all the answers

The major energy storage molecule found in all organisms is

ATP Signup and view all the answers

What organism is not correctly matched to its energy source?

Chemoheterotroph - Fe2+ Signup and view all the answers

Which metabolic process produces the fewest ATP molecules?

Fermentation Signup and view all the answers

Which of the following lists the sequence of events during aerobic respiration in the correct order?

Glycolysis, Krebs, electron transport Signup and view all the answers

Where in the environment might you find microbes conducting anaerobic respiration?

In the gut of a cow Signup and view all the answers

Most bacteria grow best at a pH of approximately

7 Signup and view all the answers

Most fungi grow best at a pH of approximately

5.5 Signup and view all the answers

A culture medium consisting of agar, human blood, and beef heart is a

Complex medium Signup and view all the answers

Which chemical nutrient is found in ATP, RNA, DNA, and membranes?

P Signup and view all the answers

Which of the following nutrients is only needed in small amounts by microorganisms?

Sulfur Signup and view all the answers

Which of the following is the best method to sterilize heat-sensitive solutions such as antibiotics?

Membrane filtration Signup and view all the answers

Which of the following is NOT true about agar?

It is consumed by microbes in media Signup and view all the answers

Which of the following would be the most effective method to sterilize petri plates inside a cardboard box?

Gamma radiation Signup and view all the answers

What types of microbial growth medium makes it easy to visually distinguish colonies of specific types of microbes?

Differential media Signup and view all the answers

Which of the following methods is most effective at killing microbes?

Boiling Signup and view all the answers

Which of the following refers to the removal of pathogens and the lowering of microbial numbers, but not the complete destruction of all bacterial life?

Disinfection Signup and view all the answers

Which of the following is important for the effectiveness of an antimicrobial treatment?

All of the above Signup and view all the answers

Heat kills microbes by

Denaturing enzymes Signup and view all the answers

Which microbe is most resistant to being killed?

Endospores of bacteria Signup and view all the answers

The major energy storage molecule found in all organisms is

ATP Signup and view all the answers

Which of the following is the best definition of fermentation?

The release of energy from the breakdown of organic molecules without oxygen, using an internally-produced, energy rich organic molecule as the final electron acceptor Signup and view all the answers

The term obligate anaerobe refers to an organism that

Is killed by oxygen Signup and view all the answers

For commercial antimicrobial treatment of canned foods, it is important to kill

Clostridium endospores Signup and view all the answers

A single celled, eukaryotic, motile organism that ingests its food is a

Protozoan Signup and view all the answers

Which of the following is true about penicillin and its discovery?

Penicillin was discovered by accident, when fungi contaminated bacterial cultures Signup and view all the answers

Aerobic respiration differs from anaerobic respiration in which of the following respects?

The final electron acceptors are different Signup and view all the answers

Some bacteria, such as Clostridium and Bacillus, can form ________, allowing them to resist heat, lack of water, and toxic chemicals.

Endospores Signup and view all the answers

In the electron transport chain, ATP is generated when

Protons flow across a membrane Signup and view all the answers

A multicellular organism that has chitin cell walls and absorbs organic material is a

Fungus Signup and view all the answers

Which of the following statements is true?

Viruses cannot reproduce outside of a host cell Signup and view all the answers

Which type of bacterium has a thick outer layer of peptidoglycan, which dehydrates in alcohol, trapping crystal violet-iodine inside the cell?

Gram-positive Signup and view all the answers

A capsule or slime that forms a layer on the outside of bacterial cells, allowing them to stick to surfaces, is called a

Glycocalyx Signup and view all the answers

Salts and sugars work to preserve foods by creating a

Hypertonic environment Signup and view all the answers

Which of the following has to consume carbohydrates for both carbon and energy?

Chemoheterotroph Signup and view all the answers

Which of the following is the type of bond between molecules of water, which provides water with some of its most important properties, including surface tension and high heat capacity?

Hydrogen bonds Signup and view all the answers

Which microbes are easiest to kill?

Enveloped viruses Signup and view all the answers

Which of the following is a eukaryotic domain in the three domain system?

Eukarya Signup and view all the answers

Which of the following organisms reproduces using binary fission?

Bacteria Signup and view all the answers

Which of the following is a prokaryotic domain in the three domain system?

Archaea Signup and view all the answers

A single-celled organism with a nucleus and chloroplasts is a

Alga Signup and view all the answers

Which of the following statements is true?

Most microbes do not cause disease Signup and view all the answers

Which of the following is true about fungi?

All are heterotrophs Signup and view all the answers

Which of the following did not occur during the Golden Age of Microbiology?

The discovery of bacteria Signup and view all the answers

Most microorganisms are not disease-causing.

True Signup and view all the answers

According to the chemiosmotic mechanism, ATP is generated when

Protons flow across a membrane from an area of high concentration to an area of low concentration Signup and view all the answers

Archaeans called extreme halophiles prefer to live in environments with high levels of

Salt Signup and view all the answers

Laboratory practices that prevent contamination in the lab are called _________ techniques.

Aseptic Signup and view all the answers

In microscopy, with which objective lens is immersion oil typically used?

100x Signup and view all the answers

In which century were microorganisms first observed by humans?

1600s Signup and view all the answers

Where in the environment might you find microbes conducting anaerobic respiration?

In the gut of a cow Signup and view all the answers

Which of the following describes the swimming movement of a motile microbe toward the light?

Phototaxis Signup and view all the answers

A gene is best defined as

A sequence of nucleotides in DNA that codes for a functional product Signup and view all the answers

Study Notes

Eukaryotic and Prokaryotic Domains

Eukaryotic domain in the three-domain system: Eukarya.
Prokaryotic domains: Bacteria and Archaea.
Microorganisms in the eukaryotic domain include Fungi, Algae, and Protozoa.

Historical Figures in Microbiology

Antonie van Leeuwenhoek: First to observe microorganisms with a microscope.
Louis Pasteur: Conducted experiments disproving spontaneous generation, developed pasteurization.
Robert Koch: Refined aseptic techniques; pivotal in establishing germ theory of disease.

Microbial Growth and Nutrition

Facultative anaerobes can grow with or without oxygen.
Chemoheterotrophs require carbohydrates for both carbon and energy.
Psychrophiles thrive at low temperatures, while thermophiles prefer warmer environments.

Cellular Components and Functions

Phospholipids make up cell membranes, providing structure and signaling.
Mitochondria are sites for cellular respiration in eukaryotic cells.
Bacterial cell wall protects against osmotic lysis; differs in gram-positive and gram-negative bacteria.

Respiratory Pathways

Aerobic respiration requires oxygen; anaerobic respiration does not.
Final electron acceptors differ: oxygen for aerobic, various substances for anaerobic respiration.

Enzymatic and Metabolic Processes

Enzymes are proteins that facilitate biological reactions by lowering activation energy.
Fermentation is energy production without oxygen, using an internally produced organic molecule as the final electron acceptor.

Sterilization and Growth Media

Aseptic techniques prevent contamination in laboratories.
Membrane filtration sterilizes heat-sensitive solutions.
Differential media help distinguish between types of microbes based on their biochemical characteristics.

Microbial Resistance and Evolution

Endospores are resistant structures formed by some bacteria to survive extreme conditions.
Antibiotic use acts as a selection agent encouraging the evolution of resistance in bacteria.

Important Microbial Characteristics

Most bacteria grow best at a neutral pH (~7).
Fungi prefer slightly acidic environments (~5.5) for optimal growth.
Viruses cannot reproduce outside a host cell and are neither prokaryotic nor eukaryotic.

Key Nutritional Compounds

ATP is the primary energy storage molecule for all organisms.
Chitin is a component of fungal cell walls; it differs from bacterial peptidoglycan.
Microorganisms utilize various nutrients, with some required only in small amounts (e.g., trace elements).

Microscopy and Laboratory Techniques

Immersion oil is used with 100x objective lenses to improve resolution.
Autoclaving is effective for sterilization, while dry heat may not be suitable for all materials.

Microbial Interactions

Normal microbiota are typically harmless or beneficial bacteria associated with humans.
Mutualistic relationships can aid in nutrient absorption, while pathogenic organisms can cause disease.

Modern Microbiology Research

The endosymbiotic theory posits eukaryotic cells evolved from engulfed prokaryotic cells.
Current microbial research focuses on understanding resistance mechanisms and microbial ecosystems.

Microbial Evolution Concepts

Chemiosmotic mechanism describes ATP generation through proton flow across membranes.
Understanding microbial genetics aids in applications such as biotechnology and antibiotic resistance studies.

These notes provide a comprehensive overview of critical microbiological concepts, historical milestones, and essential characteristics impacting both research and practical applications in the field.### Gene Transfer and Transformation

Vertical gene transfer involves the passing of genes from parent to offspring.
Horizontal gene transfer methods include conjugation, transformation, and transduction.
Transformation involves the uptake of naked DNA by a bacterium.

Mutations

Mutations are generally neutral or harmful, not typically beneficial. The statement regarding mutations being usually beneficial is false.

Evolution of Resistance

The evolution of resistance in organisms requires both mutation and selection.
Conjugation and plasmid transfer may aid in resistance but are not solely required.

PCR (Polymerase Chain Reaction)

The process of PCR does not include the copying of mRNA to form DNA; this is a step intrinsic to reverse transcription.
Steps in PCR include primer hybridization, DNA synthesis, and heating DNA to form single strands.

Restriction Enzymes

Restriction enzymes recognize and cut specific DNA sequences, essential for various DNA manipulation techniques.

cDNA Libraries

cDNA libraries lack intron sequences, providing a more accurate representation of expressed genes compared to genomic libraries.
They are useful for cloning eukaryotic genes as they exclude non-coding regions.

Blue-White Screening

X-gal is included in the culture medium to differentiate between recombinant and non-recombinant plasmids in blue-white screening.
This method allows for the selection of successful cloning events by color change.

Genomic Libraries

Genomic libraries contain collections of clones with random DNA fragments from an entire genome.
cDNA libraries, while also collections of clones, specifically represent expressed genes.

DNA Polymerase

Heat-tolerant DNA polymerase is predominantly used in the polymerase chain reaction due to its stability at high temperatures during the denaturation phase.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Test your knowledge with these flashcards on microbiology concepts and definitions. Each card focuses on key topics such as eukaryotic domains and historical figures in microbiology. Perfect for students looking to sharpen their understanding of the subject.