Microbiology Chapter 4 Flashcards

Questions and Answers

The term prokaryotes refers to which of the following?

Very small organisms

Unicellular organisms that have no nucleus (correct)

Cells that resemble animal cells more than plant cells

Multicellular organisms

The term microbiota refers to which of the following?

All microorganisms of the same species

All microorganisms in a certain geographic region

All microorganisms in a certain region of the human body (correct)

All of the microorganisms involved in a symbiotic relationship

Which of the following refers to the type of interaction between two prokaryotic populations in which one benefits and the other is not affected?

Mutualism

Parasitism

Commensalism (correct)

Neutralism

Which of the following describes Proteobacteria in domain Bacteria?

Phylum Signup and view all the answers

All Alphaproteobacteria are which of the following?

Oilotrophs Signup and view all the answers

Class Betaproteobacteria includes all but which of the following genera?

Campylobacter Signup and view all the answers

Haemophilus influenzae is a common cause of which of the following?

Upper respiratory tract infection Signup and view all the answers

Which of the following is the organelle that spirochetes use to propel themselves?

Axial filament Signup and view all the answers

Which of the following bacteria are the most prevalent in the human gut?

Bacteroides Signup and view all the answers

Which of the following refers to photosynthesis performed by bacteria with the use of water as the donor of electrons?

Oxygenic Signup and view all the answers

Which of the following bacterial species is classified as high G+C gram positive?

Corynebacterium diphtheriae Signup and view all the answers

The term 'deeply branching' refers to which of the following?

The position in the evolutionary tree of deeply branching bacteria Signup and view all the answers

Which of these deeply branching bacteria is considered a polyextremophile?

Mycobacterium tuberculosis Signup and view all the answers

Archaea and Bacteria are most similar in terms of their __________.

unicellular structure Signup and view all the answers

Which of the following is true of archaea that produce methane?

They live in the most extreme environments Signup and view all the answers

Among prokaryotes, there are some that can live in every environment on earth.

True Signup and view all the answers

When prokaryotes live as interacting communities in which one population benefits to the harm of the other, the type of symbiosis is called __________.

parasitism Signup and view all the answers

The domain __________ does not include prokaryotes.

Eukaryotes Signup and view all the answers

Pathogenic bacteria that are part of the transient microbiota can sometimes be eliminated by __________ therapy.

antibiotic Signup and view all the answers

Nitrogen-fixing bacteria provide other organisms with usable nitrogen in the form of __________.

nitrites/nitrates Signup and view all the answers

Rickettsias are __________ intracellular bacteria.

obligate Signup and view all the answers

The species __________, which belongs to Epsilonproteobacteria, causes peptic ulcers of the stomach and duodenum.

Heliobacter Signup and view all the answers

The genus Salmonella belongs to the class __________ and includes pathogens that cause salmonellosis and typhoid fever.

Gammaproteobacteria Signup and view all the answers

The bacterium that causes syphilis is called __________.

Treponema Signup and view all the answers

Bacteria in the genus Rhodospirillum that use hydrogen for oxidation and fix nitrogen are __________ bacteria.

purple nonsulfur Signup and view all the answers

Streptococcus is the __________ of bacteria that is responsible for many human diseases.

lactobacilli Signup and view all the answers

One species of Streptococcus, S.pyogenes, is classified as a __________ pathogen due to the characteristic production of pus in infections it causes.

pyogenic Signup and view all the answers

Propionibacterium belongs to __________ G+C gram-positive bacteria. One of its species is used in the food industry and another causes acne.

low Signup and view all the answers

The length of the branches of the evolutionary tree characterizes the evolutionary __________ between organisms.

distance Signup and view all the answers

The deeply branching bacteria are thought to be the form of life closest to the last universal .

common ancestor Signup and view all the answers

Many of the deeply branching bacteria are aquatic and hyperthermophilic, found near underwater volcanoes and thermal ocean __________.

vents Signup and view all the answers

The deeply branching bacterium Deinococcus radiodurans is able to survive exposure to high doses of __________.

ionizing radiation Signup and view all the answers

_________ is a genus of Archaea. Its optimal environmental temperature ranges from 70 °C to 80 °C, and its optimal pH is 2-3. It oxidizes sulfur and produces sulfuric acid.

Sulfolobus Signup and view all the answers

_______ was once thought to be the cause of periodontal disease, but, more recently, the causal relationship between this archaean and the disease was not confirmed.

Methanogens- Methanobreuibacter oralis Signup and view all the answers

Compare commensalism and amensalism.

Commensalism is when one organism benefits and the other is unaffected, while amensalism is when one is harmed and the other is unaffected. Signup and view all the answers

Give an example of the changes of human microbiota that result from medical intervention.

Natural birth babies will come first in contact with Lactobacillus, whereas C-section babies will have completely different microbes, leading to lower immune systems. Signup and view all the answers

What is the metabolic difference between coliforms and noncoliforms? Which category contains several species of intestinal pathogens?

Coliforms are able to ferment lactose completely while noncoliforms can't ferment lactose or can ferment incompletely. Noncoliforms include several species of intestinal pathogens. Signup and view all the answers

Why are Mycoplasma and Chlamydia classified as obligate intracellular pathogens?

They are classified as obligate intracellular pathogens because part of their life cycle must occur inside the other cells called host cells. Signup and view all the answers

Explain the term CFB group and name the genera that this group includes.

CFB are gram-negative nonproteobacteria that include Cytophaga, Fusobacterium, and Bacteroides, which share a similar sequence of nucleotides in their DNA. Signup and view all the answers

Name and briefly describe the bacterium that causes Lyme disease.

Borrelia burgdorferi, it's a spirochete responsible for Lyme disease. Signup and view all the answers

Characterize the phylum Cyanobacteria.

Cyanobacteria are nonproteobacteria, the largest phylum, and are key parts of ecosystems. Their cellular immune system originated from them. Signup and view all the answers

Name and describe two types of S.aureus that show multiple antibiotic resistance.

Methicillin-resistant and vancomycin-resistant S.aureus. Signup and view all the answers

Briefly describe the significance of deeply branching bacteria for basic science and for industry.

Deeply branching bacteria are important for our understanding of evolution and may provide clues regarding the structure and function of ancient and now extinct forms of life. Signup and view all the answers

What is thought to account for the unique radiation resistance of D.radiodurans?

The special ability is attributed to some unique mechanisms of DNA repair. Signup and view all the answers

What accounts for the purple color in salt ponds inhabited by halophilic archaea?

They get the color from the pigments bacteriochlorophylls and carotenoids. Signup and view all the answers

What evidence supports the hypothesis that some archaea live on Mars?

Because the mixture of gases produced by methanogens resembles the makeup of the Martian atmosphere. Signup and view all the answers

Study Notes

Prokaryotes and Microbiota

Prokaryotes are unicellular organisms that lack a nucleus.
Microbiota refers to all microorganisms within a specific region of the human body.

Interactions and Classifications

Commensalism describes an interaction where one organism benefits while the other is unaffected.
Proteobacteria is classified as a phylum within the domain Bacteria.

Alphaproteobacteria Characteristics

Alphaproteobacteria are recognized as oligotrophs, thriving in low-nutrient environments.

Betaproteobacteria Genera

Class Betaproteobacteria includes Neisseria, Bordetella, and Lepothrix, but not Campylobacter.

Respiratory Infections

Haemophilus influenzae commonly causes upper respiratory tract infections.

Spirochetes Movement

Spirochetes utilize axial filaments to propel themselves.

Gut Flora

Bactericides are the most prevalent bacteria found in the human gut.

Photosynthetic Bacteria

Photosynthesis performed by bacteria using water as an electron donor is termed oxygenic.

High G+C Gram-positive Bacteria

Corynebacterium diphtheriae is classified as a high G+C gram-positive bacterium.

Deeply Branching Bacteria

The term "deeply branching" refers to the position of these bacteria on the evolutionary tree.
Mycobacterium tuberculosis is regarded as a polyextremophile among deeply branching bacteria.

Archaea and Bacteria Similarities

Archaea and Bacteria share unicellular structures, among other characteristics.

Methanogenic Archaea

Archaea that produce methane predominantly live in extreme environments.

Prokaryotes in Various Environments

Many prokaryotes can inhabit virtually every environment on Earth.

Types of Symbiosis

Parasitism occurs when one population benefits at the expense of another.

Prokaryote Domains

The domain Eukaryotes does not include prokaryotes.

Antibiotic Therapy

Transient microbiota can sometimes be eliminated through antibiotic therapy.

Nitrogen-fixing Bacteria

Nitrogen-fixing bacteria convert nitrogen into nitrites/nitrates for use by other organisms.

Intracellular Bacteria

Rickettsias are classified as obligate intracellular bacteria.

Ulcer-Causing Bacteria

Heliobacter is a genus responsible for peptic ulcers.

Salmonella Classification

Salmonella belongs to the class Gammaproteobacteria.

Bacteria Causing Syphilis

Treponema is the bacterium responsible for syphilis.

Bacteria in Nitrogen Fixation

Purple nonsulfur bacteria, such as Rhodospirillum, are involved in hydrogen oxidation and nitrogen fixation.

Pathogenic Streptococcus

Streptococcus is a genus known for causing various human diseases.

Pyogenic Pathogen

Streptococcus pyogenes is classified as a pyogenic pathogen due to pus production in infections.

G+C Content in Propionibacterium

Propionibacterium is categorized as low G+C gram-positive bacteria.

Evolutionary Relationships

The length of branches in the evolutionary tree reflects the evolutionary distance between organisms.

Common Ancestor

Deeply branching bacteria are thought to be closest to the last universal common ancestor.

Habitats of Deeply Branching Bacteria

These bacteria predominantly inhabit aquatic environments, especially near underwater volcanoes.

Radiation Resistance

Deinococcus radiodurans exhibits resistance to high doses of ionizing radiation due to unique DNA repair mechanisms.

Sulfolobus Characteristics

Sulfolobus is an archaeal genus thriving at high temperatures and low pH, oxidizing sulfur and producing sulfuric acid.

Methanogens and Periodontal Disease

Methanobrevibacter oralis was previously linked to periodontal disease, but this relationship has not been confirmed.

Commensalism vs Amensalism

Commensalism involves one organism benefiting while the other remains unaffected, whereas amensalism involves one harmed and the other unaffected.

Medical Intervention Impact on Microbiota

Natural birth exposes infants to lactobacillus, while C-section delivery results in different microbial exposure, affecting immune systems.

Metabolic Differences

Coliforms fully ferment lactose, while noncoliforms either do not ferment it or do so incompletely.

Obligate Intracellular Pathogens

Mycoplasma and Chlamydia require host cells for part of their life cycle, classifying them as obligate intracellular pathogens.

CFB Group Characteristics

The CFB group consists of gram-negative nonproteobacteria, including Cytophaga, Fusobacterium, and Bacteroides, sharing similar DNA sequences.

Lyme Disease Bacterium

Borrelia burgdorferi, a spirochete, is the causative agent of Lyme disease.

Cyanobacteria Traits

Cyanobacteria is the largest phylum of nonproteobacteria, vital in cellular immunity and ecological functions.

Antibiotic Resistance in Staphylococcus aureus

Methicillin-resistant (MRSA) and vancomycin-resistant Staphylococcus aureus (VRSA) are notable for multiple antibiotic resistances.

Deeply Branching Bacteria Significance

These bacteria offer insights into evolution and may reveal information about extinct life forms, contributing to scientific understanding and industry applications.

Radiation Resistance in Deinococcus radiodurans

This bacterium's unique ability to withstand radiation is attributed to specialized DNA repair mechanisms.

Purple Color in Salt Ponds

Halophilic archaea exhibit purple coloration due to pigments such as bacteriochlorophylls and carotenoids.

Evidence of Archaea on Mars

The gas mix produced by methanogens mirrors that of the Martian atmosphere, supporting the hypothesis of archaeal life on Mars.

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Description

This quiz covers key concepts from Chapter 4 of Microbiology, focusing on the definitions and characteristics of prokaryotes and microbiota. Test your understanding of these essential microbiological terms and improve your knowledge through these flashcards.