BIO 124 Chapter 26 UPDATED ACTUAL
Exam Questions and CORRECT Answers
What do some photosynthetic bacteria use as a source of electrons instead of water? - CORRECT
ANSWER - hydrogen sulfide (H2S)
What are organisms called that use inorganic compounds as electron donors in cellular
respiration? - CORRECT ANSWER - lithotrophs
Unlike plant cell walls that contain cellulose, bacterial cell walls are composed of ________. -
CORRECT ANSWER - peptidoglycan
When using Koch's postulates, which of the following is an essential requirement for the
suspected pathogen? - CORRECT ANSWER - It is present in all organisms with the
disease
What has metagenomic analysis allowed researchers to do for the first time? - CORRECT
ANSWER - study organisms that cannot be cultured (grown in the lab)
Biologists often use the term "energy source" as a synonym for "electron donor." Why? -
CORRECT ANSWER - An electron donor provides the potential energy required to
produce ATP.
The text claims that the evolution of an oxygen-rich atmosphere paved the way for increasingly
efficient cellular respiration and higher growth rates in organisms. Explain. - CORRECT
ANSWER - Large amounts of potential energy are released and ATP produced when
oxygen is the electron acceptor, because oxygen is so electronegative. Large body size and high
growth rates are not possible without large amounts of ATP.
The researchers who observed that magnetite was produced by bacterial cultures from the deep
subsurface carried out a follow-up experiment. These biologists treated some of the cultures with
a drug that poisons the enzymes involved in electron transport chains. In cultures where the drug
was present, no more magnetite was produced. Does this result support or undermine their
Exam Questions and CORRECT Answers
What do some photosynthetic bacteria use as a source of electrons instead of water? - CORRECT
ANSWER - hydrogen sulfide (H2S)
What are organisms called that use inorganic compounds as electron donors in cellular
respiration? - CORRECT ANSWER - lithotrophs
Unlike plant cell walls that contain cellulose, bacterial cell walls are composed of ________. -
CORRECT ANSWER - peptidoglycan
When using Koch's postulates, which of the following is an essential requirement for the
suspected pathogen? - CORRECT ANSWER - It is present in all organisms with the
disease
What has metagenomic analysis allowed researchers to do for the first time? - CORRECT
ANSWER - study organisms that cannot be cultured (grown in the lab)
Biologists often use the term "energy source" as a synonym for "electron donor." Why? -
CORRECT ANSWER - An electron donor provides the potential energy required to
produce ATP.
The text claims that the evolution of an oxygen-rich atmosphere paved the way for increasingly
efficient cellular respiration and higher growth rates in organisms. Explain. - CORRECT
ANSWER - Large amounts of potential energy are released and ATP produced when
oxygen is the electron acceptor, because oxygen is so electronegative. Large body size and high
growth rates are not possible without large amounts of ATP.
The researchers who observed that magnetite was produced by bacterial cultures from the deep
subsurface carried out a follow-up experiment. These biologists treated some of the cultures with
a drug that poisons the enzymes involved in electron transport chains. In cultures where the drug
was present, no more magnetite was produced. Does this result support or undermine their
