CAMPBELL BIOLOGY CHAPTER 27-30
EXAM Q’S AND A’S
anaerobic respiration - answer- A catabolic pathway in which inorganic molecules
other than oxygen accept electrons at the "downhill" end of electron transport chains.
biofilm - answer- A surface-coating colony of one or more species of prokaryotes that
engage in metabolic cooperation.
bioremediation - answer- The use of organisms to detoxify and restore polluted and
degraded ecosystems.
capsule - answer- (1) In many prokaryotes, a dense and well-defined layer of
polysaccharide or protein that surrounds the cell wall and is sticky, protecting the cell
and enabling it to adhere to substrates or other cells. (2) The sporangium of a
bryophyte (moss, liverwort, or hornwort).
chemoautotroph - answer- An organism that obtains energy by oxidizing inorganic
substances and needs only carbon dioxide as a carbon source.
chemoheterotroph - answer- An organism that requires organic molecules for both
energy and carbon.
commensalism - answer- A +/0 ecological interaction in which one organism benefits
but the other is neither helped nor harmed.
conjugation - answer- (1) In prokaryotes, the direct transfer of DNA between two
cells that are temporarily joined. When the two cells are members of different
species, conjugation results in horizontal gene transfer. (2) In ciliates, a sexual
process in which two cells exchange haploid micronuclei but do not reproduce.
decomposer - answer- An organism that absorbs nutrients from nonliving organic
material such as corpses, fallen plant material, and the wastes of living organisms
and converts them to inorganic forms; a detritivore.
endospore - answer- A thick-coated, resistant cell produced by some bacterial cells
when they are exposed to harsh conditions.
endotoxin - answer- A toxic component of the outer membrane of certain gram-
negative bacteria that is released only when the bacteria die.
exotoxin - answer- A toxic protein that is secreted by a prokaryote or other pathogen
and that produces specific symptoms, even if the pathogen is no longer present.
extreme halophile - answer- An organism that lives in a highly saline environment,
such as the Great Salt Lake or the Dead Sea.
, extreme thermophile - answer- An organism that thrives in hot environments (often
60−80°C or hotter).
extremophile - answer- An organism that lives in environmental conditions so
extreme that few other species can survive there. They include extreme halophiles
("salt lovers") and extreme thermophiles ("heat lovers").
facultative anaerobe - answer- An organism that makes ATP by aerobic respiration if
oxygen is present but that switches to anaerobic respiration or fermentation if oxygen
is not present.
F factor - answer- In bacteria, the DNA segment that confers the ability to form pili for
conjugation and associated functions required for the transfer of DNA from donor to
recipient. It may exist as a plasmid or be integrated into the bacterial chromosome.
fimbria (plural, fimbriae) - answer- A short, hairlike appendage of a prokaryotic cell
that helps it adhere to the substrate or to other cells.
F plasmid - answer- The plasmid form of the F factor.
gram-negative - answer- Describing the group of bacteria that have a cell wall that is
structurally more complex and contains less peptidoglycan than the cell wall of gram-
positive bacteria. Bacteria that fall under this are often more toxic than gram-positive
bacteria.
gram-positive - answer- Describing the group of bacteria that have a cell wall that is
structurally less complex and contains more peptidoglycan than the cell wall of gram-
negative bacteria. Bacteria that fall under this are usually less toxic than gram-
negative bacteria.
Gram stain - answer- A staining method that distinguishes between two different
kinds of bacterial cell walls; may be used to help determine medical response to an
infection.
heterocyst - answer- A specialized cell that engages in nitrogen fixation in some
filamentous cyanobacteria; also called a heterocyte.
host - answer- The larger participant in a symbiotic relationship, often providing a
home and food source for the smaller symbiont.
mean - answer- The sum of all data points in a data set divided by the number of
data points.
methanogen - answer- An organism that produces methane as a waste product of
the way it obtains energy. All known organisms in this category are in domain
Archaea.
mutualism - answer- A +/+ ecological interaction that benefits each of the interacting
species.
EXAM Q’S AND A’S
anaerobic respiration - answer- A catabolic pathway in which inorganic molecules
other than oxygen accept electrons at the "downhill" end of electron transport chains.
biofilm - answer- A surface-coating colony of one or more species of prokaryotes that
engage in metabolic cooperation.
bioremediation - answer- The use of organisms to detoxify and restore polluted and
degraded ecosystems.
capsule - answer- (1) In many prokaryotes, a dense and well-defined layer of
polysaccharide or protein that surrounds the cell wall and is sticky, protecting the cell
and enabling it to adhere to substrates or other cells. (2) The sporangium of a
bryophyte (moss, liverwort, or hornwort).
chemoautotroph - answer- An organism that obtains energy by oxidizing inorganic
substances and needs only carbon dioxide as a carbon source.
chemoheterotroph - answer- An organism that requires organic molecules for both
energy and carbon.
commensalism - answer- A +/0 ecological interaction in which one organism benefits
but the other is neither helped nor harmed.
conjugation - answer- (1) In prokaryotes, the direct transfer of DNA between two
cells that are temporarily joined. When the two cells are members of different
species, conjugation results in horizontal gene transfer. (2) In ciliates, a sexual
process in which two cells exchange haploid micronuclei but do not reproduce.
decomposer - answer- An organism that absorbs nutrients from nonliving organic
material such as corpses, fallen plant material, and the wastes of living organisms
and converts them to inorganic forms; a detritivore.
endospore - answer- A thick-coated, resistant cell produced by some bacterial cells
when they are exposed to harsh conditions.
endotoxin - answer- A toxic component of the outer membrane of certain gram-
negative bacteria that is released only when the bacteria die.
exotoxin - answer- A toxic protein that is secreted by a prokaryote or other pathogen
and that produces specific symptoms, even if the pathogen is no longer present.
extreme halophile - answer- An organism that lives in a highly saline environment,
such as the Great Salt Lake or the Dead Sea.
, extreme thermophile - answer- An organism that thrives in hot environments (often
60−80°C or hotter).
extremophile - answer- An organism that lives in environmental conditions so
extreme that few other species can survive there. They include extreme halophiles
("salt lovers") and extreme thermophiles ("heat lovers").
facultative anaerobe - answer- An organism that makes ATP by aerobic respiration if
oxygen is present but that switches to anaerobic respiration or fermentation if oxygen
is not present.
F factor - answer- In bacteria, the DNA segment that confers the ability to form pili for
conjugation and associated functions required for the transfer of DNA from donor to
recipient. It may exist as a plasmid or be integrated into the bacterial chromosome.
fimbria (plural, fimbriae) - answer- A short, hairlike appendage of a prokaryotic cell
that helps it adhere to the substrate or to other cells.
F plasmid - answer- The plasmid form of the F factor.
gram-negative - answer- Describing the group of bacteria that have a cell wall that is
structurally more complex and contains less peptidoglycan than the cell wall of gram-
positive bacteria. Bacteria that fall under this are often more toxic than gram-positive
bacteria.
gram-positive - answer- Describing the group of bacteria that have a cell wall that is
structurally less complex and contains more peptidoglycan than the cell wall of gram-
negative bacteria. Bacteria that fall under this are usually less toxic than gram-
negative bacteria.
Gram stain - answer- A staining method that distinguishes between two different
kinds of bacterial cell walls; may be used to help determine medical response to an
infection.
heterocyst - answer- A specialized cell that engages in nitrogen fixation in some
filamentous cyanobacteria; also called a heterocyte.
host - answer- The larger participant in a symbiotic relationship, often providing a
home and food source for the smaller symbiont.
mean - answer- The sum of all data points in a data set divided by the number of
data points.
methanogen - answer- An organism that produces methane as a waste product of
the way it obtains energy. All known organisms in this category are in domain
Archaea.
mutualism - answer- A +/+ ecological interaction that benefits each of the interacting
species.
