C HAPTER 23: M ICROBIAL S YMBIOSES
Test Bank for Brock Biology of Microorganism 16th Edition by Michael T.
Madigan
23.1 Multiple Choice Questions
1. Two organisms that both benefit from each other are in a sym biotic
relationship called
A) ammensalism.
B) commensalism.
C) mutualism.
D) parasitism.
2. The insect symbiont Wolbachia can be used to suppress disease
transmission by mosquitoes because
A) Wolbachia supplies essential nutrients to the mosquito Culex
quinquefasciatus.
B) onl y Wolbachia-infected mosquitoes can transmit viral diseases such
as dengue fever.
C) Wolbachia infections can spread rapidl y through a mosquito
population, killing all the mosquitoes.
D) Wolbachia-infected male mosquitoes sterilize uninfected female
mosquitoes.
3. Aphids that feed on carbohydrate -rich but nutrient -poor foods obtain from
their endosymbiotic bacterial partners.
A) ATP
B) amino acids
C) ammonium
D) volatile fatt y acids
,4. Plant root nodules are
A) formed from gall-rotting bacteria that decompose plant roots.
B) harmful to plants, because the bacteria outcompete the plants for
nutrients.
C) sites where nitrogen fixation occurs.
D) structures created by fungi and are found in all agricultural crops.
5. The function of leghemoglobin in root nodules is to
A) bind oxygen.
B) chelate iron.
C) produce iron.
D) produce nitrogen.
6. What is the primary difference between a bacteroid a bacterial cell?
A) There are genetic differences that can be detected using 16S rRNA
gene sequencing.
B) They are biochemicall y very different from bacterial cells.
C) Their cell morphology is different from bacterial morphology.
D) They have genetic differences that can be detected using DNA
sequencing.
7. The specificit y of certain rhizobia to infect onl y particular plants is in
part due to the
A) abundance of nutrients present in the soil.
B) nifH genes they possess.
C) rhizobial lipids that act as signaling molecules.
D) season (time of year).
8. The mutualism of Azo lla-Anabaena is useful for
A) aquaculturalists.
B) corn farmers.
, C) rice farmers.
D) tropical forest communit y succession.
9. Which bacterium contains a large Ti plasmid and causes crown gall
disease in plants?
A) Agrobacterium rhizogenes
B) Agrobacterium tumefaciens
C) Aliivibrio fischeri
D) But yrivibrio fibrisolvens
10.In insects, primary symbionts are ________, while secondary symbionts
are _________.
A) heritable / not heritable
B) able to replicate outside of the host / obligate symbionts
C) required for host reproduction / n ot required for host reproduction
D) obligate symbionts / sometimes free -living
11.How are root nodule and arbuscular m ycorrhizal symbioses similar?
A) They both use lipochitin oligosaccharide signaling factors to initiate
root colonization.
B) They both suppl y nitrogen to the host plant through nitrogen fixation.
C) They both increase absorption of nutrients from soil.
D) They are both required for the growth and reproduction of their host
plants.
12.The signaling factors of arbuscular m ycorrhizae most likel y gave ris e to
the signaling factors used in rhizobial nodule formation, yet less is known
about arbuscular m ycorrhizae because
A) they cannot be maintained in pure culture.
B) they are not as important for plant health.
C) no genetic systems have been developed for fungi .
Test Bank for Brock Biology of Microorganism 16th Edition by Michael T.
Madigan
23.1 Multiple Choice Questions
1. Two organisms that both benefit from each other are in a sym biotic
relationship called
A) ammensalism.
B) commensalism.
C) mutualism.
D) parasitism.
2. The insect symbiont Wolbachia can be used to suppress disease
transmission by mosquitoes because
A) Wolbachia supplies essential nutrients to the mosquito Culex
quinquefasciatus.
B) onl y Wolbachia-infected mosquitoes can transmit viral diseases such
as dengue fever.
C) Wolbachia infections can spread rapidl y through a mosquito
population, killing all the mosquitoes.
D) Wolbachia-infected male mosquitoes sterilize uninfected female
mosquitoes.
3. Aphids that feed on carbohydrate -rich but nutrient -poor foods obtain from
their endosymbiotic bacterial partners.
A) ATP
B) amino acids
C) ammonium
D) volatile fatt y acids
,4. Plant root nodules are
A) formed from gall-rotting bacteria that decompose plant roots.
B) harmful to plants, because the bacteria outcompete the plants for
nutrients.
C) sites where nitrogen fixation occurs.
D) structures created by fungi and are found in all agricultural crops.
5. The function of leghemoglobin in root nodules is to
A) bind oxygen.
B) chelate iron.
C) produce iron.
D) produce nitrogen.
6. What is the primary difference between a bacteroid a bacterial cell?
A) There are genetic differences that can be detected using 16S rRNA
gene sequencing.
B) They are biochemicall y very different from bacterial cells.
C) Their cell morphology is different from bacterial morphology.
D) They have genetic differences that can be detected using DNA
sequencing.
7. The specificit y of certain rhizobia to infect onl y particular plants is in
part due to the
A) abundance of nutrients present in the soil.
B) nifH genes they possess.
C) rhizobial lipids that act as signaling molecules.
D) season (time of year).
8. The mutualism of Azo lla-Anabaena is useful for
A) aquaculturalists.
B) corn farmers.
, C) rice farmers.
D) tropical forest communit y succession.
9. Which bacterium contains a large Ti plasmid and causes crown gall
disease in plants?
A) Agrobacterium rhizogenes
B) Agrobacterium tumefaciens
C) Aliivibrio fischeri
D) But yrivibrio fibrisolvens
10.In insects, primary symbionts are ________, while secondary symbionts
are _________.
A) heritable / not heritable
B) able to replicate outside of the host / obligate symbionts
C) required for host reproduction / n ot required for host reproduction
D) obligate symbionts / sometimes free -living
11.How are root nodule and arbuscular m ycorrhizal symbioses similar?
A) They both use lipochitin oligosaccharide signaling factors to initiate
root colonization.
B) They both suppl y nitrogen to the host plant through nitrogen fixation.
C) They both increase absorption of nutrients from soil.
D) They are both required for the growth and reproduction of their host
plants.
12.The signaling factors of arbuscular m ycorrhizae most likel y gave ris e to
the signaling factors used in rhizobial nodule formation, yet less is known
about arbuscular m ycorrhizae because
A) they cannot be maintained in pure culture.
B) they are not as important for plant health.
C) no genetic systems have been developed for fungi .
