Unit 4 Quesitons Flashcards
What is most infectious microbe?
Wolfbachia
What bacteria has gliding ability for predation?
Myxococcus Xanthus
What is most dangerous animal?
Mosquitoes (has ability to pass on diseases)
What if all prokaryote suddenly vanished from Earth suddenly?
No organism would be abl;e to live since nutrient cycling and biogeochemical cycling will be shut down as most prokaryotes responsible
Which process provide greatest amount of free energy?
Aerobic respiration
Which processes provide least amount of free energy?
Methanogenesis by archaea
What elements contain intermediate oxidationt state forms?
Carbon, nitrogen, sulfur
What elements contain no intermediate oxidation state forms?
Iron, phosphate, maganase
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%
d) 50%
Archaea and reducing bacteria work together to oxidize methane using sulfate as the terminal electron acceptor in the process of ___ methanogenesis
Reverse
Which gas is most abudant greenhouse gase in the atmosphere?
Methan (CH4)
____ is group of low molecular weight organic molecules that can bind Fe3+ and facilitate its uptake by cells
Siderophores
What is regarded as major CO2 sinks?
forest
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
a) 1 million
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
a) Bacteriocins
d) Molecules that interfere with quorum sensing
e) Proteases that degrade adhesins
A group of microbes that provides activities and metabolites required for health and homeostasis of the host is called ___________
functional core microbiome
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
a) closely related strains or species
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
d) the bacteriophage carries genes that expand the cell’s metabolism
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
c) complete the digestion of cellulose
e) convert (fix) nitrogen to a usable form
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
a) high in hydrogen sulfide
d) devoid of oxygen
e) up to 350°C
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
a) phototrophy
b) lithotrophy
The unique hemoglobin of giant red tube worms (Riftia spp) transports which two gases to the animal’s trophosome?
oxygen and hydrogen sulfide
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
b) each individual species is capable of growth in the absence of the other
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
b) Both are symbiotic relationships
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.
b) Aphids harbor obligate mutualistic bacteria.