Deck 17: Microbial Symbionts

Question 1

Herbivores require microorganisms to help them with the digestion of this compound.

A) starch
B) glycogen
C) cellulose
D) proteins
E) nucleic acids

Answer 1

C

Question 2

Which of these is TRUE of an ectosymbiont?

A) It is always harmful to the host.
B) It is either harmful or beneficial to the host.
C) It is always beneficial to the host.
D) It is best described as a mutualistic relationship.
E) It is best described as a commensal relationship.

Answer 2

B

Question 3

In order to make sufficient ATP for symbiotic nitrogen fixation,the plant supplies the symbionts with ____________ for energy production.

A) NADH
B) glucose
C) C3 acids
D) fatty acids
E) C4-dicarboxylic acids

Answer 3

E

Question 4

What is an endophyte?

A) A parasite of a plant.
B) A parasite of an animal.
C) A symbiont that lives inside plant cells.
D) A member of the plant root rhizosphere.
E) A member of the intestinal tract microbial community.

Question 5

Which of these is the MOST abundant bacterial group in the colon?

A) members of the phylum Proteobacteria
B) the family Enterobacteriaceae
C) obligate anaerobes
D) facultative anaerobes
E) lactobacilli.

Question 6

What is the human microbiome composed of?

A) Microbes that live in the intestinal tract of humans.
B) All the microbes that cause disease in humans.
C) All microbes that live on or within the human body.
D) Microbes that contribute to the health of humans.
E) Microbes that live on human skin.

Question 7

Which of these is TRUE of ruminants?

A) They possess a single stomach chamber and long cecum.
B) They are considered to be hindgut fermenters.
C) They are inefficient in the digestion of plant material.
D) They obtain nutrients from digestion carried out by rumen microorganisms.
E) They often consume their own feces.

Question 8

Some herbivorous cecal fermenters obtain additional nutrients from their food sources by this method.

A) Regurgitating their food and chewing it again.
B) Retaining it in their large intestine for long periods of time.
C) Eating their feces.
D) Selectively eating certain plants.
E) Moving the cecal-digested food back to the small intestine for absorption.

Question 9

Which of these is TRUE of a lichen?

A) It is classified as a plant.
B) It is comprised of a fungus and usually an green alga.
C) It is comprised of a fungus and an archaeal symbiont.
D) It is a type of slime mold.
E) It is comprised of a protozoan and anarchaeal symbiont.

Question 10

The most common inhabitants of the human skin are members of which phyla?

A) Proteobacteria and Bacteroidetes
B) Proteobacteria and Firmicutes
C) Bacteroidetes and Firmicutes
D) Firmicutes and Actinobacteria
E) Actinobacteria and Proteobacteria

Question 11

Which of these is characteristic of the nitrogenase enzyme?

A) It is produced by both prokaryotes and eukaryotes.
B) It converts dinitrogen to nitrate.
C) It requires hydrogen gas for activity.
D) It is irreversibly inactivated by oxygen.
E) It is found in all plant symbionts.

Question 12

The vagina of women of child-bearing age has an acidic pH.This is due to the colonization by which organisms?

A) staphylococci
B) lactobacilli
C) Candida sp
D) Bacteroides sp
E) micrococci

Question 13

Many of the rumen bacteria specialize in the breakdown of these macromolecules.

A) proteins
B) cellulose polymers
C) peptidoglycans
D) nucleic acids
E) fatty acids

Question 14

Which of these is true of a mutualistic relationship?

A) Neither organism benefits or is harmed by the relationship.
B) One member benefits and the other member is harmed.
C) One member benefits and the other member does not receive any benefit.
D) Both organisms benefit.
E) Both members are harmed from the relationship.

Question 15

The mycobiont of a lichen receives sugars from the photobiont as a benefit from this relationship while the photobiont receives _______________ from the mycobiont as a benefit.

A) amino acids
B) ATP
C) inorganic nutrients and protection from desiccation
D) protection from predation
E) vitamins and amino acids

Question 16

The host-range specificity between specific legumes with specific rhizobia involves the transcriptional inactivation of the bacterial nod genes through the secretion of specific ___________ by the plant.

A) flavonoids
B) sugars
C) fatty acids
D) nucleotides
E) lactones

Question 17

The majority of Archaea found in the human intestinal tract are _____ .

A) sulfate-reducing bacteria
B) halobacteria
C) sulfide oxidizing bacteria
D) methanogens
E) fermenters

Question 18

Once rhizobia enter the plant cell through the infection thread they undergo rapid multiplication and differentiation into pleomorphic nitrogen fixing cells called _____ .

A) shizonts
B) bacteroids
C) elementary bodies
D) reticulate forms
E) nitromorphs

Question 19

The red color of plant root nodules is due to this oxygen binding protein.

A) cytochrome c
B) flavoprotein
C) leghemoglobin
D) menaquinone
E) nitrate reductase

Question 20

Lichens reproduce asexually by ___________,which are hyphal -packaged algae cells.

A) soredia
B) ascus
C) conidia
D) zygospores
E) sporozoites

Question 21

Most microbial symbionts of invertebrates are in this group.

A) yeast
B) Archaea
C) protozoa
D) algae
E) Bacteria

Question 22

Which of the following is NOT a feature of a primary endosymbiont?

A) They all have reduced genomes.
B) They are found in specialized cells called bacteriocytes.
C) They provide the host with nutrients.
D) They are passed on maternally.
E) They are required for survival or fertility.

Question 23

The human colon contains more microbial cells than human cells that make up the entire body.

Question 24

Acetogenesis is the production of acetic acid from which material(s)?

A) lactate
B) pyruvate
C) carbon dioxide and hydrogen
D) oxaloacetate
E) glucose

Question 25

Microbes in the rumen are very efficient at converting ____________ and _________ into amino acids.

A) ammonia and urea
B) glucose and pyruvate
C) starch and cellulose
D) fatty acids and acetate
E) pyruvate and lactate

Question 26

Once rhizobia enter into the plant cell and differentiate they will not proliferate again.

Question 27

Which of these contains zooxanthellae as photosynthetic symbionts?

A) shipworms
B) termites
C) lichens
D) coral
E) tubeworms

Question 28

The nitrogenase enzyme is irreversibly inactivated by hydrogen.

Question 29

Cellulose consumed by the lower termite is hydrolyzed by cellulases produced by _____ .

A) fungi
B) bacteria
C) archaeons
D) the termite
E) yeast

Question 30

Bradyrhizobium japonicum will form nodules on soybeans but not on peas,alfalfa,or beans.

Question 31

How do primary endosymbionts of insects differ from secondary endosymbionts?

A) Primary endosymbionts provide the insect with nutrients.
B) Secondary endosymbionts protect the insect from harmful bacteria.
C) Secondary endosymbionts do not remain with the host after three or four generations.
D) Primary endosymbionts show evidence of co-speciation with the host insect.
E) Secondary endosymbionts can easily be cultured.

Question 32

How do termites obtain nitrogen in their diet?

A) From digestion of proteins.
B) From digestion of nucleic acids.
C) From nitrogen fixing bacteria in their gut.
D) From urea.
E) From nitrogen fixing protozoa.

Question 33

Intestinal microorganisms are important for the proper functioning of the immune system.

Question 34

Most microbe-host relationships are harmful.

Question 35

Lower termites feed primarily on wood and contain symbiotic:

A) bacteria in their intestine.
B) bacteria and archaeons in their intestine.
C) fungi in their intestine.
D) protozoa, bacteria, and archaeons in their intestine.
E) protozoa and fungi in their intestine.

Question 36

The hydrogen and carbon dioxide produced in the gut of the lower termite are used to produce __________ by symbiotic microbes.

A) methane
B) lactate
C) fatty acids
D) amino acids
E) glucose

Question 37

Scientists are able to make an insect symbiont free by this method.

A) Hatching insect eggs in a sterile environment.
B) Treating the insect with an antibiotic.
C) Mating the insect with a symbiont free insect.
D) Irradiating insect eggs.
E) Putting the insect on a different diet.

Question 38

The bacterial genus ___________ is a secondary symbiont and is capable of changing the female to male ratio of an insect to primarily female.

A) Rickettsia
B) Wolbachia
C) Pseudomonas
D) Culex
E) Bordetella

Question 39

When the diet of a ruminant is drastically changed from grass to a starch rich diet,the ruminant may become very ill or die because:

A) the microbes in the rumen cannot break down starch.
B) of the production of large amounts of acid, resulting in acidosis.
C) they lack a source of protein.
D) they are unable to regurgitate the starch as cud.
E) the starch is broken down very slowly and the rumen becomes clogged.

Question 40

Plaque on human teeth is considered a biofilm.

Question 41

The heaviest colonized area of the human body is the __________.

Question 42

Endophytes are microorganisms that live within the tissue of ___________.

Question 43

A group of microorganisms that are interdependent on one another for the stability of the community is called a/an__________________

Question 44

The type of symbiotic relationship in which one member benefits and the other member is not affected is called _________________.

Question 45

Describe the process of rumen fermentation and nutrient acquisition by ruminants.

Question 46

All microorganisms that live on or within the human body are referred to collectively as the human ________________.

Question 47

Most endosymbionts of invertebrates can easily be cultured.

Question 48

Describe the process of rhizobial recognition of its host legume for the initiation of nodule formation.

Question 49

Describe the characteristics of a primary endosymbiont.

Question 50

Hindgut fermenters have greater fermentation efficiency than ruminants.