Question 1

The deinococci stain gram-positive but have a layered cell wall and an outer membrane that is more like a gram-negative organism.

Accepted Answer

Deinococci have a unique cell wall structure, with multiple layers and an outer membrane similar to gram-negative organisms, but they still stain gram-positive due to the thick peptidoglycan layer in their cell wall.

Question 2

Thermotogae can grow anaerobically on which of the following?

Accepted Answer

B

Question 3

Aquifex cannot use which of the following as electron donors?

Accepted Answer

Aquifex is a chemoautotrophic bacteria that uses carbon dioxide as a carbon source and gains its energy from oxidizing inorganic compounds. It can use hydrogen, thiosulfate, and sulfur as electron donors, but not glucose since glucose is an organic compound.

Question 4

Some cyanobacteria form __________, which are comprised of chains of bacterial cells that are in close contact with one another over a large area.

Accepted Answer

Cyanobacteria form trichromes, which are chains of cells in close contact with each other over a large area. Hyphae and mycelia are structures found in fungi, and cell mats are not a specific structure formed by cyanobacteria.

Question 5

Cyanobacteria capable of fixing atmospheric N₂ always produce heterocysts.

Accepted Answer

Not all cyanobacteria that fix atmospheric nitrogen produce heterocysts; some can fix nitrogen without forming these specialized cells.

Question 6

The chlorosomes of Chlorobia are attached to the plasma membrane by a lipid-derived baseplate.

Accepted Answer

Chlorosomes in Chlorobia (green sulfur bacteria) are attached to the plasma membrane by a proteinaceous baseplate, not a lipid-derived one.

Question 7

Green sulfur bacteria are nonmotile but can control their depth by using gas vesicles to control buoyancy.

Accepted Answer

Green sulfur bacteria are able to control their depth in water by using gas vesicles to regulate their buoyancy. However, they are generally nonmotile and cannot move actively through their environment.

Question 8

Prochlorophytes lack which of the following?

Accepted Answer

The answer of Prochlorophytes lack which of the following?
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Question 9

Which of the following bacteria is both photosynthetic and Gram-positive?

Accepted Answer

The answer of Which of the following bacteria is both...

Question 10

Which of the following best describes the photosynthetic membranes of Chlorobia?

Accepted Answer

In Chlorobia, the accessory bacteriochlorophylls are indeed located in the chlorosomes, which are specialized light-harvesting structures. The reaction center bacteriochlorophyll, where the primary photochemical reactions occur, is located in the plasma membrane. This arrangement allows for efficient capture and transfer of light energy to the reaction centers.

Question 11

The phylum _______ is thought to represent the oldest branch of the bacteria.

Accepted Answer

Aquificae is considered to represent the oldest branch of the bacteria, as it includes some of the most primitive known types of bacteria that are capable of surviving in extremely hot environments, which are thought to resemble early Earth conditions.

Question 12

The member of the domain Bacteria whose genome shows it to be most closely related to the Archaea is

Accepted Answer

Thermotoga has been shown to have a genome that is more closely related to the Archaea than to other bacterial lineages. This is based on phylogenetic analyses of conserved genetic markers.

Question 13

Some species of cyanobacteria can fix atmospheric nitrogen.

Accepted Answer

Some species of cyanobacteria, such as Anabaena and Nostoc, are able to fix atmospheric nitrogen, which means they can convert nitrogen gas from the air into a usable form for biological processes. This ability is important for the ecosystem as it provides a source of nitrogen for other organisms in the food chain.

Question 14

Members of the phylum Thermotogae can be found growing in

Accepted Answer

Members of the phylum Thermotogae are known for their ability to grow in high temperature environments. They are commonly found in marine hydrothermal vents and terrestrial solfataric hot springs, where temperatures can reach up to 90°C. While some members of the phylum have been found in other environments, such as soils of the Antarctic, their prevalence in high temperature habitats makes option A the best choice. Members of this phylum are not typically found in the intestinal tract of mammals.

Question 15

Which of the following is extremely radiation resistant?

Accepted Answer

Deinococcus is extremely radiation resistant due to its ability to repair DNA damage caused by radiation. It is capable of withstanding high levels of ionizing radiation, UV radiation, and desiccation. Aquifex, Thermotoga, and Cytophaga are not known for their radiation resistance.

Question 16

The ability of the deinococci to resist radiation is due in part to an unusual ability to repair chromosome damage, even fragmentation.

Accepted Answer

The statement is correct. Deinococci are known for their high resistance to radiation, and one of the reasons for this is their ability to repair chromosome damage, including fragmentation, through a unique process involving multiple DNA repair mechanisms.

Question 17

Which of the following are used by cyanobacteria for reproduction?

Accepted Answer

Cyanobacteria can use all of the above methods for reproduction. Binary fission involves the splitting of a single organism into two daughter cells, budding is when small growths develop on the parent organism and eventually break off to form new individuals, and fragmentation is when the organism breaks apart into pieces which can each grow into new individuals.

Question 18

Cyanobacteria are so named because many species have a blue-green appearance caused by the photosynthetic pigment phycocyanin.

Accepted Answer

The statement is true. Cyanobacteria are named for their blue-green color caused by the pigment phycocyanin, which is involved in photosynthesis.

Question 19

Deinococci can be isolated from ground meat, feces, air, freshwater, and other sources, but their natural habitat is soil.

Accepted Answer

The answer of Deinococci can be isolated from ground meat,...

Question 20

A trichome is a bacterial cell with three different photosynthetic pigments.

Accepted Answer

A trichome is actually a specialized outgrowth or hair-like extension found on the surface of certain plant species, algae, and cyanobacteria. It is not a bacterial cell with photosynthetic pigments.

Quiz 19: Bacteria the Deinococci and Nonproteobacteria Gram Negatives