Question 1

Compare and contrast two different ecological strategies that sulfide-oxidizing bacteria use to access sulfide and oxygen.

Accepted Answer

The answer of Compare and contrast two different ecological strategies...

Question 2

Bacteria that contain complex internal membrane systems are more likely to divide by budding than by binary fission.

Accepted Answer

Bacteria with complex internal membrane systems such as planctomycetes and certain Proteobacteria divide predominantly by budding rather than binary fission.

Question 3

What is convergent evolution and how is it different from horizontal gene transfer?

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The answer of What is convergent evolution and how is...

Question 4

Prosthecae are thought to be an adaptation to growth in nutrient-rich environments such as sediments and sewage.

Accepted Answer

Prosthecae are cellular appendages that increase surface area for nutrient absorption, typically giving an advantage in nutrient-poor environments by facilitating more efficient uptake of scarce resources.

Question 5

Discuss the ecological importance of the enzyme nitrogenase, the diversity and physiology of the various groups of organisms that contain it, and the strategies these organisms use to optimize conditions for the enzyme.

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Question 6

How do Cyanobacteria impact the ecology of both aquatic and terrestrial environments on Earth?

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Question 7

Spirilla and spirochetes are closely related bacteria that exhibit a unique corkscrew motility.

Accepted Answer

Spirilla and spirochetes both exhibit a corkscrew-like shape and motility, but they belong to different bacterial groups with distinct characteristics. Spirilla are rigid and use flagella for movement, while spirochetes are flexible and move by axial filaments.

Question 8

Budding bacteria form new cell wall material at a single point rather than throughout the whole cell.

Accepted Answer

Budding bacteria form new cell wall material at a single point known as the septum. This is where the new cell wall is synthesized and eventually separates the two daughter cells.

Question 9

Design an enrichment strategy for the isolation of a heterotrophic sulfate-reducer that could help clean up the oil spill in the sediments of the Gulf of Mexico.

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The answer of Design an enrichment strategy for the isolation...

Question 10

Budding is a form of reproduction whereby prokaryotic microbes can reproduce sexually.

Accepted Answer

Budding is a form of asexual reproduction commonly observed in yeast and some other unicellular organisms. Prokaryotic microbes, such as bacteria, reproduce by binary fission, which is a form of asexual reproduction. They do not reproduce sexually.

Question 11

All phototrophic bacteria use a monophyletic photosystem in photosynthesis, thus there is intense competition for light between different phototrophic bacteria.

Accepted Answer

While it is true that all phototrophic bacteria use a monophyletic photosystem in photosynthesis, not all phototrophic bacteria necessarily compete for light. Some bacteria can thrive in lower light conditions or may use alternative sources of energy besides light. Therefore, the statement is incorrect and the answer is B.

Question 12

What functional group (or groups) of microbes would be most useful in a microbial fuel cell in which electrons are transferred to and from solid metal electrodes? Why?

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The answer of What functional group (or groups) of microbes...

Question 13

Bacteria and Archaea are general single-celled organisms, but some phyla form sheaths around multiple cells to facilitate attachment and filament formation.

Accepted Answer

Some phyla of bacteria and archaea do indeed form sheaths around multiple cells, which helps them attach to surfaces and form filaments. Examples include the cyanobacteria and the Proteobacteria.

Question 14

Thiobacillus species are acidophilic chemolithotrophs capable of autotrophic growth. They perform the dissimilative oxidation of H₂S, Sᵒ, thiosulfate, or Fe⁺². Diagram or explain how Thiobacillus species obtain carbon and energy for growth and predict what type of environment they would be found in.

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Question 15

Tilling or plowing is a common agriculture practice that has been proven to have a profound impact on the nitrogen cycle. Tilling breaks up hard soils to ease the planting and germination of crops, and it also introduces more oxygen into the soil. Many fertilizers contain N in the form of ammonia because ammonia is readily absorbed and used by plants, while N in the form of nitrate is more mobile and is more easily lost from the soil. Based on your knowledge of microbial transformations of inorganic nitrogen species, what impact would you predict extensive tilling to have on the fate of ammonium-based nitrogen fertilizer?

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The answer of Tilling or plowing is a common agriculture...

Question 16

Bioluminescence is a social behavior of bacterial cells that causes luminescence to occur when a dense cell population has been attained.

Accepted Answer

Bioluminescence is a social behavior of bacterial cells where they produce light in response to a high cell density. This occurs due to the release of signaling molecules that cause the expression of genes involved in bioluminescence.

Question 17

Given that multiple diverse phyla (e.g., diverse phylogenetic groups) of microorganisms can perform similar functions in ecosystems, how we might predict the microbial functions performed by a particular organism or in a particular environment without relying on growing all of the microbes in the lab?

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Question 18

Based on the FUNCTIONAL characteristics of the Cyanobacteria and Proteobacteria phyla, which phylum do you think is more deeply rooted in the tree of life (i.e., which phylum branches off closer to the last universal common ancestor)? Use at least two pieces of evidence to support your answer. How could you test your hypothesis?

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The answer of Based on the FUNCTIONAL characteristics of the...

Question 19

Magnetosomes are specialized magnetic structures, found in iron-reducing bacteria, that aid in chemotaxis towards iron-oxides.

Accepted Answer

Magnetosomes are specialized organelles found in magnetotactic bacteria, not specifically iron-reducing bacteria, and they aid in navigation along the Earth's magnetic field lines, not chemotaxis towards iron-oxides.

Question 20

Organisms that fix dinitrogen gas into ammonia are called diazotrophs.

Accepted Answer

This statement is true. Diazotrophs are organisms that have the ability to convert dinitrogen gas in the atmosphere into ammonia, which can then be used by plants and other organisms for growth and development. Some examples of diazotrophs include certain types of bacteria and cyanobacteria.

Quiz 15: Functional Diversity of Microorganisms