Question 1

Photoreceptors are analogous to chemoreceptors in that they are both proteinaceous sensors.

Accepted Answer

A) True 
 B)False  True

Question 2

You have discovered a new microorganism,but you want to know if it is a eukaryote or a prokaryote.To investigate this question you prepare a slide with a simple stain and view it with a light microscope with a 40X objective lens and 10X ocular lens.You also prepare a control slide using Saccharomyces cerevisiae (a unicellular eukaryote).You can see the cells on your control slide,but you don't see cells when you look at your unknown microorganism.What can you conclude from this experiment?

Accepted Answer

A)  The experiment failed to visualize the organism because the stain killed it. 
B)  Your new unknown microorganism is probably a virus. 
C)  The cells of the new unknown microorganism may be too small to see with the objective and ocular lenses you used. 
D)  The new unknown microorganism is probably an archaeon. 
A)  The experiment failed to visualize the organism because the stain killed it. 
B)  Your new unknown microorganism is probably a virus. 
C)  The cells of the new unknown microorganism may be too small to see with the objective and ocular lenses you used. 
D)  The new unknown microorganism is probably an archaeon. C

Question 3

You are studying swimming motility in a pathogenic bacillus.You create mutations in random genes and then test which mutations effect swimming motility by looking at the mutant cells under the microscope.One of the mutant bacteria can not swim anymore,but still rotates around in a one spot when you watch them.Using electron microscopy you discover that some parts of the flagella are still present in the cell wall,but no long flagella are visible.Which gene do you think is mutated (i.e.,missing)and which motility-related parts are still present in this mutant?

Accepted Answer

The flagellar apparatus is put together in a particular order first the MS ring,anchoring proteins,and the hook extend off of the cytoplasmic membrane.Flagellin proteins then pass through the narrow filament channel and cap proteins finally are put onto the end when roughly 20,000 flagellin have been assembled.Flagellar growth thus occurs after the assembly of the basal body,rings,and hook.The basal body provides the rotation and uses the proton motive force to rotate the basal body.From the information given above,one can infer that the basal body and hook can still rotate,but the flagellin proteins are missing or defective so that no long flagella can form.This would explain why the cells might still rotate in place,but not be able to move forward rapidly.

Question 4

Chemotaxis is a sensory response affecting the rotational direction of the flagellar motor.

Accepted Answer

A) True 
 B)False

Question 5

You have discovered a new coccoid-shaped microorganism with no nucleus,a rigid cell wall,and a diameter of 2 µm.Chemical tests reveal that its cell wall does NOT contain peptidoglycan.The new microorganism is

Accepted Answer

A)  most likely a bacterium. 
B)  most likely a eukaryote. 
C)  most likely an archaeon. 
D)  either a bacterium or an archaeon. 
A)  most likely a bacterium. 
B)  most likely a eukaryote. 
C)  most likely an archaeon. 
D)  either a bacterium or an archaeon.

Question 6

Porins are channels in the outer membranes of gram-positive Bacteria.

Accepted Answer

A) True 
 B)False

Question 7

Hydrolytic enzymes function in the

Accepted Answer

A)  initial degradation of nutrients. 
B)  transport of substrates within the cell. 
C)  chemotactic response, particularly in gram-negative Bacteria. 
D)  regeneration of the periplasm. 
A)  initial degradation of nutrients. 
B)  transport of substrates within the cell. 
C)  chemotactic response, particularly in gram-negative Bacteria. 
D)  regeneration of the periplasm.

Question 8

The lipopolysaccharide (LPS)layer is found ONLY in the cell walls of

Accepted Answer

A)  gram-positive Bacteria. 
B)  gram-negative Bacteria. 
C)  Archaea. 
D)  Eukarya. 
A)  gram-positive Bacteria. 
B)  gram-negative Bacteria. 
C)  Archaea. 
D)  Eukarya.

Question 9

Lysozyme is an enzyme that can ultimately lyse and kill eukaryotic cells by breaking β-1,4-glycosidic bonds in peptidoglycan.

Accepted Answer

A) True 
 B)False

Question 10

Teichoic acids are commonly found in gram-negative cell walls.

Accepted Answer

A) True 
 B)False

Question 11

Compare and contrast the chemical composition and structure of the cytoplasmic membranes found in Bacteria and Archaea.What is the advantage of the archaeal membranes in relationship to the types of environments many archaea inhabit?

Accepted Answer

Bacterial cytoplasmic membranes contain

Question 12

Explain why prokaryotes tend to survive and adapt more rapidly to extreme and dynamic environmental conditions than eukaryotes.

Accepted Answer

Answers will vary,but should reflect an

Question 13

Compared to Eukaryotes,Bacteria and Archaea have ________ surface-to-volume ratios,causing ________ nutrient exchange and growth rates.

Accepted Answer

A)  lower / lower 
B)  lower / higher 
C)  higher / lower 
D)  higher / higher 
A)  lower / lower 
B)  lower / higher 
C)  higher / lower 
D)  higher / higher

Question 14

Which of the following statements is TRUE?

Accepted Answer

A)  Fimbriae are generally shorter and more numerous than flagella. 
B)  Fimbriae enable cells to stick to surfaces. 
C)  Pili serve as receptors and facilitate genetic exchange between prokaryotic cells. 
D)  Fibriae are usually shorter than flagella and enable cells to adhere to surfaces, whereas pili are involved in genetic exchange. 
A)  Fimbriae are generally shorter and more numerous than flagella. 
B)  Fimbriae enable cells to stick to surfaces. 
C)  Pili serve as receptors and facilitate genetic exchange between prokaryotic cells. 
D)  Fibriae are usually shorter than flagella and enable cells to adhere to surfaces, whereas pili are involved in genetic exchange.

Question 15

Describe the mechanisms by which certain prokaryotes glide.What are the ecological advantages of gliding motility?

Accepted Answer

Mechanisms will vary depending on the or

Question 16

An organism of the genus Staphylococcus is ________,while an organism of the genus Spirochaeta is ________.

Accepted Answer

A)  spherical / rod shaped 
B)  rod shaped / coiled 
C)  spherical / coiled 
D)  coiled / spherical 
A)  spherical / rod shaped 
B)  rod shaped / coiled 
C)  spherical / coiled 
D)  coiled / spherical

Question 17

The rigid layer that is present in the cell walls of Bacteria that is primarily responsible for the strength of the wall is known as

Accepted Answer

A)  pseudomurein. 
B)  S-layer. 
C)  cellulose. 
D)  peptidoglycan. 
A)  pseudomurein. 
B)  S-layer. 
C)  cellulose. 
D)  peptidoglycan.

Question 18

In general,most cell inclusions function as energy reserves or as a reservoir of structural building blocks.

Accepted Answer

A) True 
 B)False

Question 19

Elaborate on why discovering endospores was important to microbiology.

Accepted Answer

Endospores allow bacteria to survive boi

Question 20

Which of the following types of microscopy could be used to visualize the layers of the cell membrane and the cell wall?

Accepted Answer

A)  phase-contrast microscopy 
B)  transmission electron microscopy 
C)  bright-field microscopy 
D)  confocal microscopy 
A)  phase-contrast microscopy 
B)  transmission electron microscopy 
C)  bright-field microscopy 
D)  confocal microscopy

Exam 2: Microbial Cell Structure and Function

Photoreceptors are analogous to chemoreceptors in that they are both proteinaceous sensors.

Chemotaxis is a sensory response affecting the rotational direction of the flagellar motor.

You have discovered a new coccoid-shaped microorganism with no nucleus,a rigid cell wall,and a diameter of 2 µm.Chemical tests reveal that its cell wall does NOT contain peptidoglycan.The new microorganism is

Porins are channels in the outer membranes of gram-positive Bacteria.

Hydrolytic enzymes function in the

The lipopolysaccharide (LPS)layer is found ONLY in the cell walls of

Lysozyme is an enzyme that can ultimately lyse and kill eukaryotic cells by breaking β-1,4-glycosidic bonds in peptidoglycan.

Teichoic acids are commonly found in gram-negative cell walls.

Compare and contrast the chemical composition and structure of the cytoplasmic membranes found in Bacteria and Archaea.What is the advantage of the archaeal membranes in relationship to the types of environments many archaea inhabit?

Explain why prokaryotes tend to survive and adapt more rapidly to extreme and dynamic environmental conditions than eukaryotes.

Compared to Eukaryotes,Bacteria and Archaea have ________ surface-to-volume ratios,causing ________ nutrient exchange and growth rates.

Which of the following statements is TRUE?

Describe the mechanisms by which certain prokaryotes glide.What are the ecological advantages of gliding motility?

An organism of the genus Staphylococcus is ________,while an organism of the genus Spirochaeta is ________.

The rigid layer that is present in the cell walls of Bacteria that is primarily responsible for the strength of the wall is known as

In general,most cell inclusions function as energy reserves or as a reservoir of structural building blocks.

Elaborate on why discovering endospores was important to microbiology.

Which of the following types of microscopy could be used to visualize the layers of the cell membrane and the cell wall?

Microorganisms and Microbiology

Microbial Metabolism

Molecular Biology

Microbial Growth and Control

Microbial Genomics

Metabolic Regulation

Viruses and Virology

Viral Genomes and Diversity

Genetics of Bacteria and Archaea

Genetic Engineering and Biotechnology

Microbial Evolution and Systematics

Metabolic Diversity of Microorganisms

Functional Diversity of Bacteria

Diversity of Bacteria

Diversity of Archaea

Diversity of Eukaryotic Microorganisms

Methods in Microbial Ecology

Microbial Ecosystems

Nutrient Cycles

Microbiology of the Built Environment

Microbial Symbioses

Microbial Interactions With Humans

Immunity and Host Defense

Immune Mechanisms

Molecular Immunology

Diagnostic Microbiology

Epidemiology

Person-To-Person Bacterial and Viral Diseases

Vectorborne and Soilborne Bacterial and Viral Diseases

Water and Food As Vehicles of Bacterial Diseases

Eukaryotic Pathogens: Fungal and Parasitic Diseases

Filters

Compared to Eukaryotes,Bacteria and Archaea have surface-to-volume ratios,causing nutrient exchange and growth rates.

An organism of the genus Staphylococcus is ,while an organism of the genus Spirochaeta is .