Unit 4 Quesitons

Question 1

What is most infectious microbe?

Answer 1

Wolfbachia

Question 2

What bacteria has gliding ability for predation?

Answer 2

Myxococcus Xanthus

Question 3

What is most dangerous animal?

Answer 3

Mosquitoes (has ability to pass on diseases)

Question 4

What if all prokaryote suddenly vanished from Earth suddenly?

Answer 4

No organism would be abl;e to live since nutrient cycling and biogeochemical cycling will be shut down as most prokaryotes responsible

Question 5

Which process provide greatest amount of free energy?

Answer 5

Aerobic respiration

Question 6

Which processes provide least amount of free energy?

Answer 6

Methanogenesis by archaea

Question 7

What elements contain intermediate oxidationt state forms?

Answer 7

Carbon, nitrogen, sulfur

Question 7

What elements contain no intermediate oxidation state forms?

Answer 7

Iron, phosphate, maganase

Question 8

Approximately how much of the total carbon on Earth is fixed by microbes such as diatoms and cyanobacteria?

a) 10%
b) 20%
c) 30%
e) 50%
e) 90%

Answer 8

d) 50%

Question 9

Archaea and reducing bacteria work together to oxidize methane using sulfate as the terminal electron acceptor in the process of ___ methanogenesis

Answer 9

Reverse

Question 9

Which gas is most abudant greenhouse gase in the atmosphere?

Answer 9

Methan (CH4)

Question 10

____ is group of low molecular weight organic molecules that can bind Fe3+ and facilitate its uptake by cells

Answer 10

Siderophores

Question 11

What is regarded as major CO2 sinks?

Answer 11

forest

Question 12

The human body has roughly 22,000 protein-encoding genes, but the number of genes present in the microbiome is over ______.
a) 1 million
b) 3,000
c) 8 million
d) 50,000

Answer 12

a) 1 million

Question 13

Which three of the following are produced by Staphylococcus epidermis to interfere with the growth of other bacteria on the skin, such as S. aureus?
a) Bacteriocins
b) Antibodies
c) Hormones
d) Molecules that interfere with quorum sensing
e) Proteases that degrade adhesins

Answer 13

a) Bacteriocins
d) Molecules that interfere with quorum sensing
e) Proteases that degrade adhesins

Question 14

A group of microbes that provides activities and metabolites required for health and homeostasis of the host is called ___________

Answer 14

functional core microbiome

Question 15

Bacteriocins are toxic peptides produced by Gram-positive bacteria that target ______.
a) closely related strains or species
b) endospores
c) most Gram-positive bacteria
d) Gram-negative bacteria

Answer 15

a) closely related strains or species

Question 16

A bacteriophage that infects a bacterial cell and becomes lysogenic may be beneficial for the host bacterium when ______.

a) the bacteriophage becomes defective and cannot excise from the chromosome
b) its genes are not already present in the host CRISPR repeats
c) nutrients are limited
d) the bacteriophage carries genes that expand the cell’s metabolism

Answer 16

d) the bacteriophage carries genes that expand the cell’s metabolism

Question 17

Termites are dependent on their endosymbionts to carry out which two processes?

a) degrade chitin as a carbon source
b) generate methane gas
c) complete the digestion of cellulose
d) fix CO2 using electrons from H2S
e) convert (fix) nitrogen to a usable form

Answer 17

c) complete the digestion of cellulose
e) convert (fix) nitrogen to a usable form

Question 17

Hydrothermal vent fluids are ______. [Choose three.]

a) high in hydrogen sulfide
b) oxygen-rich
c) high in fixed nitrogen
d) devoid of oxygen
e) up to 350°C
f) around 2°C

Answer 17

a) high in hydrogen sulfide
d) devoid of oxygen
e) up to 350°C

Question 18

Microbial autotrophs, organisms who use carbon dioxide as their carbon source, fuel the reactions to fix CO2 by either _____ or ______.

a) phototrophy
b) lithotrophy
c) auxotrophy
d) heterotrophy

Answer 18

a) phototrophy
b) lithotrophy

Question 19

The unique hemoglobin of giant red tube worms (Riftia spp) transports which two gases to the animal’s trophosome?

Answer 19

oxygen and hydrogen sulfide

Question 20

In a facultative symbiotic interaction between two species of bacteria, Blank______.

a) each individual species requires the other for all aspects of growth and metabolism
b) each individual species is capable of growth in the absence of the other

Answer 20

b) each individual species is capable of growth in the absence of the other

Question 21

Identify the common characteristic of cooperation and mutualism.

a) Both harm one partner
b) Both are symbiotic relationships
c) Both involve a modification of the environment

Answer 21

b) Both are symbiotic relationships

Question 22

If an aphid is treated with an antibiotic, it dies. Which is the best explanation for this observation? a) Aphid cells convert antibiotics to toxins. b) Aphids harbor obligate mutualistic bacteria. c) Aphid cells are susceptible to antibiotics. d) Bacteria living in aphids become pathogenic upon exposure to antibiotics.

Answer 22

b) Aphids harbor obligate mutualistic bacteria.

Question 23

The loss of photosynthetic pigments from the endosymbiotic photosynthetic dinoflagellates of coral, or the complete expulsion of dinoflagellates from the coral, is called coral ______

Answer 23

bleaching

Question 24

An antagonistic interaction in which one partner obtains biochemical precursors and energy from a living victim is termed ______. a) predation b) competition c) parasitism

Answer 24

c) parasitism

Question 24

Which three statements describe a host-parasite relationship? a) The host must eventually eliminate the parasite. b) The parasite can kill the host immediately. c) The host must be harmed. d) The parasite must benefit. e) The parasite must coexist with the host, at least temporarily.

Answer 24

c) The host must be harmed. d) The parasite must benefit. e) The parasite must coexist with the host, at least temporarily.

Question 25

The uniquely microbial process that fuels autotrophy in some microbial primary producers is ______. a) prototrophy b) auxotrophy c) phototrophy d) lithotrophy

Answer 25

d) lithotrophy

Question 26

An antagonistic interaction in which one partner obtains biochemical precursors and energy after killing a victim is termed ______. a) predation b) competition c) parasitism

Answer 26

a) predation

Question 27

An endosymbiotic relationship where one partner benefits and one is harmed, but also involves at least a temporary state of coexistence is called ______. a. parasitism b. mutualism c. predation d. facultative cooperation

Answer 27

a. parasitism

Question 28

Which statement regarding the interaction of a temperate bacteriophage and its host bacteria is false? a. The decision of whether an infection will be lytic or lysogenic is determined by environmental factors. b. The outcome of a lytic infection is always negative for the host bacterial cell. c. The outcome of a lytic infection is always negative for the temperate bacteriophage.

Answer 28

c. The outcome of a lytic infection is always negative for the temperate bacteriophage.

Question 29

Termites are aided in the digestion of wood by ______ that complete lignocellulose degradation and by ______that fix atmospheric nitrogen. a. protists / bacteria b. archaea / bacteria c. bacteria / archaea d. protists / archaea

Answer 29

a. protists / bacteria

Question 30

An example of an obligatory symbiotic interaction is Blank______. a. Vibrio species and the bobtail squid because the Vibrio colonizes the squid every day b. "cheater" bacteria and antibiotic producers because they get the benefit but do not contribute c. a virus because it absolutely requires a host cell for replication

Answer 30

a. Vibrio species and the bobtail squid because the Vibrio colonizes the squid every day

Question 31

Aphids and Buchnera aphidicola bacteria are obligate mutualistic symbionts. Therefore, if the bacterial partner is separated from the insect and placed in a culture medium, the expected result would be that the bacteria would Blank______. a. grow more quickly than usual b. grow more slowly than usual c. die d. be unaffected

Answer 31

c. die

Question 32

If an aphid is treated with an antibiotic, it dies. Which is the best explanation for this observation? a. Aphids harbor obligate mutualistic bacteria. b. Aphid cells convert antibiotics to toxins. c. Bacteria living in aphids become pathogenic upon exposure to antibiotics. d. Aphid cells are susceptible to antibiotics.

Answer 32

a. Aphids harbor obligate mutualistic bacteria.

Question 33

the bright red color of the gill plumes of giant red tube worms (Riftia spp.) is due to a unique type of ______. a. siderophore b. hemoglobin c. myoglobin d. transferrin

Answer 33

b. hemoglobin

Question 34

In coral bleaching, which microbial component of the coral holobiont is affected? a. Ammonia oxidizing archaea in the coral skeleton b. The endosymbiotic photosynthetic dinoflagellates c, Nitrogen fixing bacteria in the mucus layer d. Chitin degrading bacteria in the mucus layer

Answer 34

b. The endosymbiotic photosynthetic dinoflagellates

Question 35

Most human diseases are transmitted by the ___ system through any other system a. respiratory b. digestive c. nervous

Answer 35

a. respiratory

Question 36

Which of the following is a fomite? a. droplets from sneeze b. pus c. contaminated needle d. insects

Answer 36

c. contaminated needle

Question 37

In one experiment, relationship between numbers and a specific infection is measured quantitatively with experimental animals. For a computation of LD ____ of 500 animals die from disease a. 100 b. 250 c. 500 d. 800

Answer 37

b. 250

Question 38

Intoxication vs. infection

Answer 38

Intoxication: disease from entry of toxin and organism does not have to enter body Infection: organism needs to enter body and go to target to attach to receptor

Question 39

Exotoxins

Answer 39

AB toxin (2 subunit protein) gram + and gram - heat susceptible (not resistant) more toxic

Question 40

Endotoxins

Answer 40

Lipid A Onlyn gram - Heat stable and resistant less toxic

Question 41

A measure of the tendency of a system to accept or donate electrons is known as the _________ _________

Answer 41

redox potential

Question 42

Sulfate, the fully oxidized species, is reduced by plants and microbes for use in amino acid and protein biosynthesis; this is described as ______

Answer 42

assimilary sulfate reduction

Question 43

Methane is a greenhouse gas of increasing concern because it has about 25 times the global warming potential of _________ _________.

Answer 43

Carbon dioxide

Question 44

Which of these results in increased numbers of beneficial bifidobacteria in a child's intestinal tract? a. Adding solid food to the diet b. Bottle feeding instead of breastfeeding c. Breastfeeding d. Switching from breast milk to cow's milk

Answer 44

c. Breastfeeding

Question 45

This figure shows the availability of alternative terminal electron acceptors as O2 concentration declines with depth in water and soil. Based on your analysis of the figure, which of the following best explains why sulfate reducing bacteria and methanogens are not evenly distributed in the same sediment ecosystem?

Answer 45

Sulfate reduction has a more negative standard free energy change (ΔG0') than methanogenesis

Question 46

The term that describes the unity of the human host and its associated microbes is ______. a. holobiont b. metagenome c. microbiome

Answer 46

a. holobiont

Question 47

The normal community of microbiota that humans host begins developing ______ and becomes a stable community of microbes by age _____. a. before birth; one b. at birth; three c. at birth; ten d. before birth; three

Answer 47

b. at birth; three

Question 48

Which of the following events is most likely to result in a long-term change in the adult microbiome? a. Receiving a vaccination against shingles b. Maintaining a gluten-free diet for a year c. Contracting influenza d. Switching to organic skin moisturizer

Answer 48

b. Maintaining a gluten-free diet for a year

Question 49

Though a process called bacterial interference, Staphylococcus epidermis produces substances that ______. a. increase inflammation b. inhibit the growth of other bacterial species on the skin c. prevent bacterial cell entry through an open wound d. interfere with wound healing

Answer 49

b. inhibit the growth of other bacterial species on the skin

Question 50

The idea that a healthy gut microbiome is protective against the establishment of pathogens in the gut is termed ______. a. immune surveillance b. probiotic tolerance c. mucosal tolerance d. colonization resistance

Answer 50

d. colonization resistance

Question 51

If bacterial interference by Lactobacillus acidophilus in the vagina is reduced as a result of antibiotic treatment or hormonal fluctuations, an overgrowth of Gram-negative anaerobes can cause a condition called bacterial _______

Answer 51

vaginosis

Question 52

True or false: The anatomy and physiology of human skin do not vary, therefore the normal microbiota of the skin is consistent throughout the body surface.

Answer 52

False

Question 53

In the duodenum, the low number of bacteria present are mostly ______. Gram negative or Gram positive

Answer 53

Gram positive

Question 54

Colonization resistance refers to the idea that Blank______. a. once the gut microbiome is established in an infant, it cannot be changed substantively b. pathogens cannot establish themselves in the gut in the presence of antibiotics c. the microbiota in the gut is protected from disease by the presence of a healthy community

Answer 54

c. the microbiota in the gut is protected from disease by the presence of a healthy community

Question 55

A yeast infection is most commonly caused by an overgrowth of which normal inhabitant of the vagina? a. Aspergillus b. Saccharomyces c. Candida d. Penicillium

Answer 55

c. Candida

Question 56

Fecal microbiome transplant from obese mice to germ-free mice results in the germ-free mice Blank______. a. maintaining their weight, when dietary fat is cut in half b. maintaining their weight, regardless of their diet c. becoming obese, regardless of their diet d. becoming obese, correlated with eating a diet of 40% fat e. becoming obese, despite running mazes for 6 hours/day

Answer 56

c. becoming obese, regardless of their diet

Question 57

Through chemical modification, gut microbes convert a liver product to Blank______ which impact the growth of other gut microbes and modulate lipid, glucose, and energy metabolism in the liver, kidney, and heart. a. bacteriocins b. coprostanols c. secondary bile acids d. proteases

Answer 57

c. secondary bile acids

Question 58

In a healthy human, which of the following tissues is normally free of microorganisms? a. Muscles b. Skin c. Mucous membranes d. Gut

Answer 58

a. Muscles

Question 59

In a healthy human, which of the following tissues is normally colonized by microorganisms? Multiple choice question. Mucous membranes Muscles incorrect Cerebrospinal fluid Blood