Bio2 Ch27- Archaea and Bacteria

Which of the following features occurs in prokaryotic and in some eukaryotic cells?

a.) a mitochondrion

b.) a cell wall

c.) a nucleoid

d.) a nucleus

b.) a cell wall

A gene that has two alleles, A and a, is located on the same chromosome as a second gene that also has two alleles, B and b. Suppose a diploid individual has alleles AB on one copy of this chromosome and alleles ab on the other copy of this chromosome. For this individual, select the pair of recombinant genotypes that could result if crossing over occurs between these two chromosomes.

a.) Ab and aB

b.) Ab and ab

c.) AB and ab

d.) AB and aB

a.) Ab and aB

What is a sister taxa?

Groups of organisms that share a common ancestor that is not shared by any other groups.

What is the function of fimbriae?

a.) They are used in motility.

b.) They are used to attach the cell to its substrate or to other prokaryotic organisms.

c.) They are used to transfer DNA during conjugation.

d.) They protect the cell from dehydration.

e.) They are components of the outer cell wall in gram-negative bacteria.

b.) They are used to attach the cell to its substrate or to other prokaryotic organisms.

Jams, jellies, preserves, honey, and other foods with high sugar content hardly ever become contaminated by bacteria, even when the food containers are left open at room temperature. Which of the following statements best explains the inability of bacteria to survive in such an environment?

a.) they are obligate anaerobes

b.) they are unable to metabolize the glucose or fructose, and thus starve to death

c.) they undergo death as a result of water loss from the cell

d.) they are unable to swim through these thick and viscous materials

c.) they undergo death as a result of water loss from the cell

Approximately how many prokaryotic cells live in 5 mL of fertile soil?

About 100 million prokaryotic cells

What is the correct order of transformation?

a.) Transformed DNA pairs with homologous region on the recipient cell chromosome, Donor cell DNA binds to a receptor site on the recipient cell, Donor cell lyses releasing pieces of its chromosome into the environment, One strand of the donor cell DNA is degraded, Transformed DNA recombines with the recipient cell chromosome

b.) Transformed DNA pairs with homologous region on the recipient cell chromosome, One strand of the donor cell DNA is degraded, Donor cell DNA binds to a receptor site on the recipient cell, Transformed DNA recombines with the recipient cell chromosome, Donor cell lyses releasing pieces of its chromosome into the environment

a.) Transformed DNA pairs with homologous region on the recipient cell chromosome, Donor cell DNA binds to a receptor site on the recipient cell, Donor cell lyses releasing pieces of its chromosome into the environment, One strand of the donor cell DNA is degraded, Transformed DNA recombines with the recipient cell chromosome

Genes for the resistance of antibiotics are often located __________.

on plasmids

A process that cannot produce genetic variation in bacterial populations is

a.) transduction.

b.) conjugation.

c.) mutation.

d.) meiosis.

d.) meiosis.

What are F- and F+ cells?

F+ cells function as DNA donors during conjugation and F- cells function as DNA recipients during conjugation

What processes leads to genetic recombination by the introduction of viral DNA into a bacterium?

Transduction

What is conjugation?

1.) Requires cell to cell contact

2.) Involves the transfer of DNA from an Hfr cell to an F- cell

What is transduction?

1.) Involves bacteriophage transferring pieces of bacterial DNA from one cell to another

2.) Involves the transfer of viral DNA from one cell to another

What is translation?

1.) Involves DNA from the environment being taken up into a bacterial cell

What are the three methods of genetic recombination?

conjugation, transduction, translation

Which of the following is true of generalized bacteriophage transduction?

a.) The bacteriophage must enter the lysogenic cycle.

b.) The bacteriophage chromosome has a region homologous to the bacterial chromosome.

c.) The bacteriophage packages fragments of bacterial DNA into new phage particles.

c.) The bacteriophage packages fragments of bacterial DNA into new phage particles.

Which of the following processes contributes to genetic recombination in prokaryotes?

a.) Meiosis

b.) Mutation

c.) Transduction

c.) Transduction

Bacteria that live around deep-sea, hot-water vents obtain energy by oxidizing inorganic hydrogen sulfide belched out by the vents. They use this energy to build organic molecules from carbon obtained from the carbon dioxide in seawater. These bacteria are __________.

chemoautotrophs

Which of the following statements about obligate anaerobes is correct?

a.) They live exclusively by cellular respiration or by anaerobic respiration.

b.) They obtain energy by oxidizing ferrous ions.

They use O2 for cellular respiration and cannot grow without it.

c.) They will use O2 if it is present, but can obtain energy by fermentation if needed.

d.) They are poisoned by O2

d.) They are poisoned by O2

What do photoautotrophs use?

light as an energy source and CO2 as a carbon source

What involves metabolic cooperation among prokaryotic cells?

biofilms

Photosynthesis that releases O2 occurs in:

a.) cyanobacteria.

b.) gram-positive bacteria.

c.) methanogens.

d.) chemoautotrophic bacteria.

a.) cyanobacteria.

Which structural characteristic allows nitrogen-fixing cells to continue to function even when in the presence of oxygen which is toxic to the cell? Why?

specialized cells called heterocysts, which have cell walls that restrict the entry of oxygen

Properties of Gram-Positive Bacteria:

a.) have a thick peptidoglycan layer

b.) appear pink after gram staining

c.) have a thin peptidoglycan layer

d.) alcohol rinse easily removes crystal violet

e.) appears purple after gram staining

f.) have an outer membrane as part of their cell wall structure

g.) alcohol rinse does not remove crystal violet

h.) have a plasma membrane

a.) have a thick peptidoglycan layer

e.) appears purple after gram staining

g.) alcohol rinse does not remove crystal violet

h.) have a plasma membrane

Properties of Gram-Negative Bacteria:

a.) have a thick peptidoglycan layer

b.) appear pink after gram staining

c.) have a thin peptidoglycan layer

d.) alcohol rinse easily removes crystal violet

e.) appears purple after gram staining

f.) have an outer membrane as part of their cell wall structure

g.) alcohol rinse does not remove crystal violet

h.) have a plasma membrane

b.) appear pink after gram staining

c.) have a thin peptidoglycan layer

d.) alcohol rinse easily removes crystal violet

f.) have an outer membrane as part of their cell wall structure

h.) have a plasma membrane

What do gram-positive and gram-negative bacteria have in common?

a plasma membrane

Azotobacter is a genus of bacteria that live in soil and have the following characteristics:

They are bacilli.

They are gram-negative.

They are obligate aerobes.

They can fix nitrogen. (Unlike some other nitrogen-fixing bacteria, which associate with the roots of plants, Azotobacter species are free-living.)

Which 4 statements are true?

a.) They appear purple after Gram staining.

b.) They require amino acids or other organic molecules as a source of nitrogen.

c.) They use O2 for cellular respiration.

d.) They are poisoned by O2

e.) They can carry out anaerobic respiration in an environment that lacks O2

f.) They have a relatively thin layer of peptidoglycan in their cell wall.

g.) They are shaped like rods.

h.) They have the appearance of coils or corkscrews.

i.) They can convert atmospheric nitrogen to ammonia.

c.) They use O2 for cellular respiration.

f.) They have a relatively thin layer of peptidoglycan in their cell wall.

g.) They are shaped like rods.

i.) They can convert atmospheric nitrogen to ammonia.

The prokaryotic organisms most likely to be found living in salt ponds are the __________.

extreme halophiles

While examining a rock surface, you have discovered an interesting new organism. Which of the following criteria will allow you to classify the organism as belonging to Bacteria but not Archaea or Eukarya?

a.) The organism does not have a nucleus.

b.) The lipids in its plasma membrane consist of glycerol bonded to straight-chain fatty acids.

c.) It can survive at a temperature over 100°C.

d.) Cell walls are made primarily of peptidoglycan.

d.) Cell walls are made primarily of peptidoglycan.

What characteristics describe most currently existing bacteria?

tiny, ubiquitous, metabolically diverse

Which of the following characteristics would allow someone to conclude that a newly discovered bacterium is a cyanobacterium?

a.) It lacks cell walls.

b.) It forms chains called mycelia.

c.) It is able to form colonies and produce oxygen.

d.) It is an endosymbiont.

c.) It is able to form colonies and produce oxygen.

Which statement about the domain Archaea is accurate?

a.) Metagenomic studies have recently revealed the existence of many previously unknown archaean species.

b.) No archaeans can inhabit solutions that are nearly 30% salt.

c.) No archaeans are adapted to waters with temperatures above the boiling point.

d.) The genomes of archaeans are unique, containing no genes that originated within bacteria.

a.) Metagenomic studies have recently revealed the existence of many previously unknown archaean species.

What trait does an archaean and a eukaryote have in common?

the presence of introns

Recently, a microbe that is able to digest cellulose was discovered in a hot spring with an average temperature of 95°C. This microbe most likely belongs to which of the following groups?

a.) Archaea

b.) Cyanobacteria

c.) Proteobacteria

d.) Spirochetes

a.) Archaea

Select the correct statement about bacteria.

a.) The majority of bacteria cause human disease.

b.) All organisms with cells containing a membrane-enclosed nucleus and organelles are eukaryotes, whereas all organisms with cells lacking a membrane-enclosed nucleus and organelles are bacteria.

c.) Certain bacteria live within rocks kilometers below the Earth's surface.

c.) Certain bacteria live within rocks kilometers below the Earth's surface.

What best describes an ecological interaction in which one organism lives on or inside another organisms and eats its cellular contents or tissues?

Parasitism

What describes a bacterium that lives in the human intestine and causes disease?

symbiotic pathogen

Most ecosystems on Earth rely on sunlight as the primary energy source for the synthesis of organic compounds that living organisms need. Sunlight does not penetrate deep enough in the ocean to provide energy for organisms living near hydrothermal vents. How can these densely populated communities survive without energy from the sun?

a.) chemoautotrophic bacteria harvest chemical energy from hydrogen sulfide and then provide the basis of food for the vent communities

b.) chemoautotrophic bacteria fix nitrogen which then is used as a source of energy for other organisms

c.) chemoheterotrophic bacteria harvest chemical energy from hydrogen sulfide and then provide the basis of food for the vent communities

d.) chemoheterotrophic bacteria convert organic compounds into carbon dioxide which is used by other organisms as an energy source

a.) chemoautotrophic bacteria harvest chemical energy from hydrogen sulfide and then provide the basis of food for the vent communities

If all prokaryotes on Earth suddenly vanished, what would be the most likely and most direct result?

the recycling of nutrients would be greatly reduced

When are endotoxins released?

Endotoxins are released only when bacteria die and their cell walls break down.

Bioremediation is __________.

the use of organisms to remove pollutants from the environment

What is one of the primary benefits of bioremediation?

a.) to clean up areas polluted with toxic compounds by using bacteria

b.) to improve human health with the help of living organisms such as bacteria

c.) to improve soil quality for plant growth by using bacteria

d.) to improve bacteria for production of useful chemicals

a.) to clean up areas polluted with toxic compounds by using bacteria

Which of the following types of pathogenic prokaryotes cause cholera?

a.) bacteria that release an exotoxin

b.) archaea that release an endotoxin

c.) archaea that release an exotoxin

d.) bacteria that release an endotoxin

a.) bacteria that release an exotoxin

Which of the following statements correctly describes a process by which bacteria become resistant to antibiotics?

a.) Bacteria reproduce slowly, allowing mutation to become widespread in a population.

b.) Horizontal gene transfer spreads antibiotic resistance genes rapidly in a population.

c.) Antibiotics cause mutation in bacteria, making them resistant.

d.) Some bacteria produce exotoxins that breakdown antibiotics, rendering them nonfunctional.

b.) Horizontal gene transfer spreads antibiotic resistance genes rapidly in a population.

Which of the following is a structure that bacteria, archaea, and eukaryotes have?

plasma membrane

Which group of bacteria is unusual in that they lack peptidoglycan in their cell walls?

Chlamydias

Which subgroup of proteobacteria contains many species that are closely associated with eukaryotic hosts in mutualistic or parasitic relationships?

Alpha

Which subgroup of proteobacteria contains many species that are predators of other bacteria?

Delta

Which of the following characteristics is a reason why a Gram-stain to distinguish gram-positive from gram-negative bacteria is an important tool in a medical diagnosis of a bacterial infection?

a.) the cell walls of many gram-negative bacteria are toxic

b.) The outer membrane of a gram-negative bacterium helps protect it from the body's defenses

c.) Certain gram-positive bacteria are resistant to antibiotics

d.) all of the above

d.) all of the above

Bacteria that are __________ tend to have abundant internal membranes.

photosynthetic

In an experiment, a microbiologist put equal numbers of each of the following organisms into a flask of sterile broth, consisting mostly of sugar and a few amino acids. She then placed the flask in the dark.

What organism would be most likely to survive?

chemoheterotrophic bacteria

What substances are required by typical nitrogen-fixing cyanobacteria?

carbon dioxide, nitrogen, water, light, and some minerals

What is the structural feature of gram-positive bacteria that results in their retaining a crystal violet dye stain and thereby being distinguished from gram-negative bacteria in a Gram-stain technique?

Gram-positive bacteria have thicker cell walls

Bacterial flagella have a very complex structure composed of 42 distinct proteins. What is the most likely explanation for the evolution of these complex structures?

Exaptation

Portions of the genomes of certain prokaryotic species are very similar to portions of the genomes of distantly related prokaryotes. The process that most likely accounts for this genetic similarity is __________.

horizontal gene transfer

Which of the following statements about cyanobacteria is true?

a.) Some are single cells, whereas others live in filamentous colonies

b.) They are the only prokaryotes that perform plant-like, oxygenic photosynthesis

c.) some species may carry on nitrogen fixation

d.) it can be said that nitrogen-fixing cyanobacteria are the most self-sufficient of all organisms

e.) all of the above

e.) all of the above

Which mechanisms is/are (a) means of genetic recombination in prokaryotes?

conjugation, transduction, transformation

Prokaryotes found inhabiting the Great Salt Lake would be __________.

extreme halophiles

Some prokaryotes stick to their substrate or to one another by means of hairlike appendages, each called a __________.

fimbria

What are the most common prokaryotic cell shapes?

spherical, rod-shaped, spiral

Acquiring an R plasmid would allow a bacterium to do what?

resist antibiotics

What does not contribute to bacteria's ability to evolve rapidly?

sexual reproduction

Bacteria function primarily in which ecological roles?

mutualism, commensalism, parasitism, decomposition

The Desulfovibrio bacterium breaks down organic matter (which it must have) and uses sulfate (not oxygen) as an electron acceptor. As a result, it produces hydrogen sulfide (H2S), accounting for the "rotten egg" smell of swamp muck. Oxygen is a deadly poison to Desulfovibrio.

We would call Desulfovibrio a(n) __________.

obligately anaerobic chemoheterotroph

Which of the following is a disease caused by bacteria?

a.) Tuberculosis

b.) Common cold

c.) aids

d.) smallpox

e.) measles

f.) none of the above

g.) all of the above

a.) Tuberculosis

Plasmids __________.

a.) replicate independently of the main chromosome

b.) often contain antibiotic resistance genes

c.) are transferred from one bacterium to another by conjugation

d.) allow bacteria to survive adverse conditions

e.) all of the above

f.) none of the above

e.) all of the above

What are biofilms?

cooperative colonies of bacteria, require metalbolic cooperation

Which of the following is not a true statement concerning bacterial flagella?

a.) bacterial flagella are homologous to the flagella of eukaryotic cells

b.) bacterial flagella are not covered by the plasma membrane as eukaryotic cells are

c.) there can be more than one flagellum on each bacteria cell

d.) bacterial flagellum enable bacteria to move

e.) bacterial flagella originate in and extend from the cell wall and plasma membrane

f.) none of the above

g.) all of the above

a.) bacterial flagella are homologous to the flagella of eukaryotic cells

What is a difference between the cell walls of prokaryotes and the cell walls of eukaryotes?

The cell walls are made of different molecules

Antibiotics administered in human medicine work against bacterial infections by __________.

Interfering with an aspect of bacterial metabolism or structure that differs from that of eukaryotic cells

Why is salt a good preservative to use for foods such as pork and fish?

Prokaryotic cells living in food will shrink from their cell walls, impacting their ability to reproduce

What is the function of a bacterial endospore?

To facilitate persistence in temporarily harsh environments