Page | 1
BIOL 2040 - Chapter 27 Quiz Questions and
Answers (Expert Solutions)
Q: Life on Earth is classified into three domains. What are they?
ANS 🗹🗹: Eukarya, Archaea and Bacteria
Q: Domains of microorganisms whose cells have a prokaryotic structure. Their cells lack
nuclei with porous envelopes and other cellular features typical of eukaryotes.
ANS 🗹🗹: Archaea and Bacteria
Q: Why type of group does not include all of the descendants of a single common
ancestor?
ANS 🗹🗹: paraphyletic group
Q: True or False? Archaea and bacteria include the smallest known cells and are the
most abundant organisms on Earth.
ANS 🗹🗹: True
Q: What does the fact that organisms classified as domain Archaea share a number of
features with those classified in Eukarya suggest?
ANS 🗹🗹: That they share a common ancestry
Q: Archaea possess distinctive membrane phospholipids which are formed by what type
of bonds?
ANS 🗹🗹: ether
Q: What type of bonds characterize the membrane phospholipids of bacteria and
eukaryotes?
ANS 🗹🗹: ester
, Page | 2
Q: These type of bonded membranes are resistant to damage by heat and other extreme
conditions, which helps explain why many archaea are able to grow in extremely harsh
conditions.
ANS 🗹🗹: ether
Q: What type of chains do archaea have in their membranes instead of fatty-acid chains?
ANS 🗹🗹: isoprene chains
Q: What is the difference in the cell walls of bacteria vs. archaea?
ANS 🗹🗹: In most bacteria, the cell wall is composed of carbohydrates that are
cross-linked by peptides (forming a substance called peptidoglycan). The cell wall of
archaea is usually a surface layer of proteins.
Q: True or False? Though many bacteria occur in soils and surface ocean waters in
moderate conditions, diverse bacteria occupy habitats with very high salt content, acidity,
methane levels, or temperatures that would kill most archaea and eukaryotes.
ANS 🗹🗹: False. Though many archaea occur in soils and surface ocean waters in
moderate conditions, diverse archaea occupy habitats with very high salt content,
acidity, methane levels, or temperatures that would kill most bacteria and
eukaryotes.
Q: An organism that occurs primarily in extreme habitats.
ANS 🗹🗹: extremophile
Q: What is an example of an extremeophile?
ANS 🗹🗹: The methane producer Methanopyrus, which grows best at deep-sea
thermal vent sites where the temperature is 98 degrees Celcius (at this temperature
the proteins of most organisms would denature, but those of Methanopyrus are
resistant to such damage). Methanopyrus is so adapted to its extremely hot
environment that it cannot grow when the temperature is less than 84 degress
Celcius.
Q: An organism that thrives in extremely hot temperatures.
ANS 🗹🗹: hyperthermophile
Q: True or False? The domain Archaea includes less than 20 phyla?
BIOL 2040 - Chapter 27 Quiz Questions and
Answers (Expert Solutions)
Q: Life on Earth is classified into three domains. What are they?
ANS 🗹🗹: Eukarya, Archaea and Bacteria
Q: Domains of microorganisms whose cells have a prokaryotic structure. Their cells lack
nuclei with porous envelopes and other cellular features typical of eukaryotes.
ANS 🗹🗹: Archaea and Bacteria
Q: Why type of group does not include all of the descendants of a single common
ancestor?
ANS 🗹🗹: paraphyletic group
Q: True or False? Archaea and bacteria include the smallest known cells and are the
most abundant organisms on Earth.
ANS 🗹🗹: True
Q: What does the fact that organisms classified as domain Archaea share a number of
features with those classified in Eukarya suggest?
ANS 🗹🗹: That they share a common ancestry
Q: Archaea possess distinctive membrane phospholipids which are formed by what type
of bonds?
ANS 🗹🗹: ether
Q: What type of bonds characterize the membrane phospholipids of bacteria and
eukaryotes?
ANS 🗹🗹: ester
, Page | 2
Q: These type of bonded membranes are resistant to damage by heat and other extreme
conditions, which helps explain why many archaea are able to grow in extremely harsh
conditions.
ANS 🗹🗹: ether
Q: What type of chains do archaea have in their membranes instead of fatty-acid chains?
ANS 🗹🗹: isoprene chains
Q: What is the difference in the cell walls of bacteria vs. archaea?
ANS 🗹🗹: In most bacteria, the cell wall is composed of carbohydrates that are
cross-linked by peptides (forming a substance called peptidoglycan). The cell wall of
archaea is usually a surface layer of proteins.
Q: True or False? Though many bacteria occur in soils and surface ocean waters in
moderate conditions, diverse bacteria occupy habitats with very high salt content, acidity,
methane levels, or temperatures that would kill most archaea and eukaryotes.
ANS 🗹🗹: False. Though many archaea occur in soils and surface ocean waters in
moderate conditions, diverse archaea occupy habitats with very high salt content,
acidity, methane levels, or temperatures that would kill most bacteria and
eukaryotes.
Q: An organism that occurs primarily in extreme habitats.
ANS 🗹🗹: extremophile
Q: What is an example of an extremeophile?
ANS 🗹🗹: The methane producer Methanopyrus, which grows best at deep-sea
thermal vent sites where the temperature is 98 degrees Celcius (at this temperature
the proteins of most organisms would denature, but those of Methanopyrus are
resistant to such damage). Methanopyrus is so adapted to its extremely hot
environment that it cannot grow when the temperature is less than 84 degress
Celcius.
Q: An organism that thrives in extremely hot temperatures.
ANS 🗹🗹: hyperthermophile
Q: True or False? The domain Archaea includes less than 20 phyla?
