microbiology chapter 27
holobiont or superorganism
Aggregations of many types of organisms in stable relationships are now often referred to as ______ or ______.
carbon dioxide as their carbon source
All primary producers are autotrophs, that is, they use ______.
predation
An antagonistic interaction in which one partner obtains biochemical precursors and energy after killing a victim is termed ______.
parasitism
An endosymbiotic relationship where one partner benefits and one is harmed but also involves at least a temporary state of coexistence is called ______.
obligatory
An individual did not get vaccinated against SARS-CoV-2 and subsequently developed COVID-19. The SARS-CoV-2 virus entered the cell via the ACE2 receptor and began to divide. For the virus, this is considered a(n) _________ interaction.
cheater
An organism that benefits from the outside production of a compound that inhibits the competition without depleting its own energy is described as a _________.
cooperative
Because you have always been fascinated by spiders and bacteria, you decide to study the microbiome of a species of spider that is locally abundant. You are able to cultivate many bacteria from the spiders gut in the lab, and the spiders do not appear to be negatively affected by treatment with antibiotics that you know will inhibit the growth of these bacteria. Based on this evidence, which of the following types of symbiotic relationships do you suspect might be occurring between the spider and the bacteria?
microbes are housed in the extracellular polysaccharide matrix
Biofilm formation offers some degree of protection from predation because ______.
Calvin Cycle
Chemolithotrophic bacteria use the electrons from sulfides to perform the ___________________ that leads to carbon fixation, producing nutrients for the tube worm.
modification
Commensalism can also involve __________________ of environment by one organism, making it more suited for another organism
amino acids
Common mutualisms are seen between insects and microbes, for example, the association between aphids and Buchnera, which provides the host with ___________________
mutualistic
Corals host dinoflagellate symbionts called zooxanthellae, which, when expelled, result in coral bleaching. Because neither the coral nor its symbiont can survive alone, this relationship is called _______________
marine invertebrates
Endosymbiotic photosynthetic dinoflagellates are often the basis for the food chain in many ______.
capture energy from a nonliving source
In an ecosystem, the primary producers _____.
methanotrophic
In peat bogs, ______________ bacteria live in sphagnum stems and oxidize methane to produce carbon dioxide that the plant can fix.
Wood-Ljungdahl pathway
In the termite gut, protists ferment cellulose to acetate, CO2, and H2. The acetate is the termite's preferred carbon source, and the CO2 and H2 are used by bacterial symbionts to produce more acetate by the ______.
Commensalism [0/+]
In what kind of microbial interaction does one organism benefit while the other is neither harmed nor helped, and does not directly depend on the host's metabolism for survival?
Facultative
In what symbiotic interactions are two individual species capable of growth in the absence of the other?
Mutualism [+/+]
In what type of microbial interaction are both partners benefitted, parters often cannot live separately, and the mutualist/host are dependent on each other?
Parasitism [0, -]
In what type of microbial interaction does one organism gain (parasite) and the other is harmed) and both host/parasite coexist?
Rumen ecosystem
Microbes convert cellulose to organic acids such as acetate in the ________________.
cellulose; acetate
Mutualism is found in termites where protists ferment _____________, releasing carbon dioxide and hydrogen that are then converted to ____________ by bacterial symbionts.
competition
Patients who take antibiotics sometimes experience overgrowth of the fungus Candida albicans in their mouths and throats (a condition called thrush). C. albicans is considered part of the gastrointestinal microbiome but its population is typically limited by the presence of other microorganisms. Based on this evidence, which of the following types of symbiotic relationship do you think occurs between members of the normal flora and C. albicans?
mutualistic
Recent metagenomic investigations reveal that the human microbiome is highly diverse, and both humans and microbes benefit. The relationship is best described as _________.
fixed carbon
Reef-building coral harbor zooxanthellae, members of the dinoflagellates that provide ________________ in exchange for nitrogenous compounds and other nutrients.
Endosymbiont; Cooperation
Rice seedling blight is a plant disease caused by the fungus Rhizopus microsporus that harbors intracellular bacteria in the genus Burkholderia. Interestingly, a toxin produced by the Burkholderia bacteria kills the seeds; the fungus then consumes the poisoned seeds. In the laboratory R. microsporus and the Burkholderia bacteria can be grown in pure culture. Which of the following pairs of words best describe this microbial symbiosis?
organic carbon
Riftia spp. are tube worms that live in communities on the ocean floor near hydrothermal vents. They lack a mouth and gut and rely on endosymbiotic bacteria to provide them with _______________________. This mutualism is so beneficial that the worms can grow to over a meter long.
equilibrium
Successful parasites have evolved to coexist in _____________ with their hosts; but if the balance is upset, the host or parasite may die
Parasitic
The chytrid fungus Batrachochytrium dendrobatidis is colonizing frogs across the globe causing massive mortality and even pushing some amphibian species to the brink of extinction. The Batrachochytrium dendrobatidis-frog relationship can be considered which of the following?
Contact-independent growth inhibition
The following describes what kind of growth inhibition? "A bacterial species produces an antibiotic that diffuses through the medium and depletes organisms that are competing for nutrients and space."
Contact-dependent growth inhibition
The following describes what kind of growth inhibition? "Salmonella ingested via undercooked chicken deliver a toxin using the T6SS projectile vehicle into organisms that make up the gut microbiome, allowing them to occupy the niche and ultimately cause disease."
X. nematophila and S. carpocapsae can be grown separately
The relationship between the bacterium Xenorhabdus nematophila and its nematode host, Steinernema carpocapsae, is classified as cooperation because both organisms benefit and _________.
chemolithotrophic
The relationship between the tube worms Riftia and sulfide-oxidizing ___________________ bacteria is mutualistic.
contact-dependent and contact-independent
The two general mechanisms for offensive action against neighboring microbes are ______.
lithotrophy
The uniquely microbial process that fuels autotrophy in some microbial primary producers is ______.
False
True or false? The difference between facultative and obligatory interactions between symbionts is that facultative organisms cannot live independently; symbiosis is crucial to their life cycle.
Predation, Parasitism, Competition
What are the three types of antagonistic microbial interactions?
One organism dominates OR two organisms share the resource
What are the two possible outcomes of competition?
Commensalism [0, +] and Amensalism [0, -]
What are the two types of one way microbial interactions?
Mutualism and Cooperation
What are the two types of two-way microbial interactions?
Increased rates of nutrient cycling
What is a benefit of predation?
Symbiosis
What is a stable association of two or more different species of organisms regardless of beneficial or negative impacts?
Termite-protozoan relationship
What is an example of a mutualism relationship?
Ectosymbiont
What is an organism located on surface of another organism?
Endosymbiont
What is an organism located within another organism?
Coevolution
What is it called when two organisms evolve together?
Symbiont
What is traditionally designated the smaller of two organisms in a symbiotic relationship?
Ammensalism [0, -]
What kind of microbial interaction has a negative impact of one organism based on release of a specific compound? (Antibiotic production by fungi and bacteria, cultivation of antibiotic-producing bacterium by ants to control fungal parasites, bacteriocin production by bacteria)
Predation [0, -]
What kind of microbial interaction involves microbes that attack others to kill as prey?
Cooperation [+, +]
What kind of microbial interaction is a form of positive symbiosis, involves syntrophic relationships, benefits both organism, and does not involve an obligatory relationship>
Epibiotic predators
What kind of predators attach to the surface of the prey, eventually causing lysis of the cell, then feeding on its cytoplasmic components e.g.,Vampirococcus?
Endobiotic predators
What kind of predators penetrates prey then directly consumes the cytoplasmic contents, e.g., Daptobacter and Bdellovibrio?
Competition [0, -]
What microbial interaction occurs when two organisms try to acquire or use the same resource?
Syntrophy
What symbiotic phenomenon occurs when one species benefits from the metabolic products of another?
Predation
When Alexander Fleming discovered what was to become penicillin, he noticed that wherever mold was growing on plates of Staphylococus sp., there was a zone of inhibition of bacterial growth around the fungi. What type of symbiotic relationship does this describe?
cooperative
You are studying the microbial communities in a marine estuary. You notice a layer of purple photosynthetic bacteria that use sulfide as an electron source. Sulfide is oxidized by these bacteria, which grow in a layer above sediment from which you have isolated sulfate-reducing bacteria that generate sulfide during anaerobic respiration. Based on this evidence, which of the following types of symbiotic relationships do you suspect might be occurring between these two types of bacteria?
predation
You have isolated a soil protozoan, which you are now trying to grow in pure culture. You have tried many different types of media but find you can only grow the protozoan if bacteria are also present in the medium. You note that the bacterial population declines as the protozoan population increases. Based on this evidence, which of the following types of symbiotic relationships do you suspect might be occurring between the protozoan and the bacteria?
within specialized cells called bacteriocytes
A mature aphid contains millions of Buchnera aphidicola cells, located ______.
epibiotic
A predatory bacterium that attaches to its prey's surface and releases degradative enzymes to lyse the prey cell is termed a(n) ______ predator.
endobiotic
A predatory bacterium that enters its prey's periplasm and consumes its energy and precursors is termed a(n) ______ predator.
