micro test 3 study questions

The genome sequence of an organism can provide information about the organism's __________. -genes, size, and function -function, evolutionary history, and morphology -function, size, and evolutionary history -genes, function, and evolutionary history

genes, function and evolutionary history

The ecological diversity of microbes is largely dependent on their complex morphological and structural diversity. t/f

false

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

true

What is the primary difference between dissimilative sulfur reducers and dissimilative sulfur oxidizers? -Dissimilative sulfur oxidizers use sulfur compounds as terminal electron acceptors, while dissimilative sulfur reducers use sulfur compounds as an energy source. -Both groups use sulfur compounds as a source of sulfur to make proteins, but in one case they must be oxidized and in the other they must be reduced due to their starting reduction potentials. -Dissimilative sulfur oxidizers use sulfur compounds as an energy source, while dissimilative sulfur reducers use sulfur compounds as terminal electron acceptors. -Dissimilative sulfur oxidizers are organiotrophs, while dissimilative sulfur reducers are lithotrophs.

-Dissimilative sulfur oxidizers use sulfur compounds as an energy source, while dissimilative sulfur reducers use sulfur compounds as terminal electron acceptors.

Horizontal gene transfer refers to the transfer of genes from one organism to another, as occurs during conjugation between bacteria. How does this differ from vertical gene transfer? -In horizontal gene transfer, genes are transferred between two organisms of the same species. In vertical gene transfer, genes are transferred between two organisms of different species. -Conjugation can involve horizontal or vertical gene transfer, depending on the physical orientation of the bacteria involved. -In horizontal gene transfer, genes are transferred from one mature adult organism to another. In vertical gene transfer, genes are transferred from adults to offspring. -In vertical gene transfer, genes are transferred by a vector such as a bacteriophage.

-In horizontal gene transfer, genes are transferred from one mature adult organism to another. In vertical gene transfer, genes are transferred from adults to offspring.

Lyme disease is a common arthropod-borne disease caused by the spirochete Borrelia burgdorferi. Which of the following best describes B. burgdorferi? -It has a flexible spiral shape with endoflagella. -It consists of multiple rods, forming an overall curved or spiral shape. -It has a rigid spiral shape. -It consists of cocci in grapelike clusters, forming complex patterns.

-It has a flexible spiral shape with endoflagella.

Aerobic methylotrophs are most likely to be found __________. -where oxygen is low -where oxygen is absent -in water and soil -in a host gut

-in water and soil

Which feature of Cyanobacteria contributes to their importance in shaping the Earth's atmosphere? -photosystem gliding motility -heterocysts -phycobilins

-photosystem

Sequencing an organism's genome often leads to identification of hypothetical proteins, which are characterized as __________. -proteins that likely exist with known functions -proteins that likely exist though their function is unknown -proteins that are expressed -proteins that are overexpressed

-proteins that likely exist though their function is unknown

What is the key difference between the purple sulfur bacteria and the purple nonsulfur bacteria? -the possible electron donors used for photosynthesis -the type of photosynthesis (oxygenic versus anoxygenic) -the carbon fixation pathway used -the types of photosynthetic pigments they have

-the possible electron donors used for photosynthesis

In a phylogeny, which two organisms would be most likely to be placed closest together after a node based only on the information given? organisms that are quite different genetically but placed within sister groups -two organisms that appear to have different lifestyles but that are both very similar genetically to a common ancestor -two organisms that are morphologically very similar; both are bacilli with similar internal and external structures -one organism and a similar organism from the outgroup of the phylogeny

-two organisms that appear to have different lifestyles but that are both very similar genetically to a common ancestor

Automated sequencing techniques require only one lane on an electrophoresis gel rather than four. What is one method that makes this possible? -Each base is identified with a different fluorescent color. -The different bases are recognized by their depth in the electrophoresis gel. -The fragments of different lengths have different charges, meaning that they travel different distances in the electrophoresis gel. -Computers are able to recognize the different bases by their structure.

Each base is identified with a different fluorescent color.

Determine why some prokaryotes have less DNA but more genes than eukaryotes. -Prokaryotes have more introns in their chromosomes. -Eukaryotes do not have introns in their chromosomes. -Eukaryotes have more introns in their chromosomes. -Eukaryotes have more exons in their chromosomes.

Eukaryotes have more introns in their chromosomes.

A recombinant cell is -is the result of a cell dividing -is a cell that receives DNA from an outside source and incorporates it into its own -donates DNA into a new cell.

is a cell that receives DNA from an outside source and incorporates it into its own

Gene duplication is thought to have had a significant influence on the evolution of microbes because __________. -the duplicated gene can serve as a "back-up" copy -the duplicated gene can be mutated, possibly leading to a useful new gene function or product, while the original copy can still perform its original (and possibly essential) genetic function -the duplicated gene can allow for increased transcription and synthesis of the gene product -the duplicated gene can be given away to another organism by conjugation

the duplicated gene can be mutated, possibly leading to a useful new gene function or product, while the original copy can still perform its original (and possibly essential) genetic function

Streptomyces are unique because __________. -some can produce antibiotics -they produce hyphae similar to fungi -most produce spores -All of the listed responses are correct.

-All of the listed responses are correct.

Spirochetes have an unusual flagellum called an endoflagellum. How does it differ from other flagella? -Most flagella rotate, but endoflagella do not. -While the anchor of most flagella extend only into the outer layer of the cell wall, endoflagella reach the cell membrane. -Most flagella extend beyond the cell wall, but endoflagella are completely located within the periplasm. -Most flagella are used for locomotion, but endoflagella are not.

-Most flagella extend beyond the cell wall, but endoflagella are completely located within the periplasm.

You are interested in trying to determine the function of a particular gene in a common bacterium (meaning that it has a haploid genome). To do this, could you use a knockout mutation? -Possibly; it would depend on whether the gene was essential for survival and on whether you could create a diploid bacteria as well. -No, the knockout technique is not ever possible in haploid organisms. -Yes; the second copy of the gene would continue to function and allow the organism to live even if the gene encoded an essential gene product. -Yes; knockout mutations can be used for any genes.

-Possibly; it would depend on whether the gene was essential for survival and on whether you could create a diploid bacteria as well.

Gas vesicles in cyanobacteria are used by the organisms for what purpose? -They have no functional purpose; they are an artifact of electron microscopy. -They allow the cells to adjust their buoyancy to maintain a certain depth in the water column. -They are a way of getting rid of excess O2 generated by photosynthesis. -They are a way of concentrating N2 gas for nitrogen fixation.

-They allow the cells to adjust their buoyancy to maintain a certain depth in the water column.

Which of the following is an example of horizontal gene transfer in bacteria? -Conjugation and transformation -Conjugation -Transduction, conjugation, and transformation -Transduction -Transformation

-Transduction, conjugation, and transformation

What is the hallmark of all horizontal gene transfers? -Transfer of DNA from parent to offspring -Transfer of DNA between organisms of the same generation -The use of plasmids -Transfer of DNA using a virus

-Transfer of DNA between organisms of the same generation

Which of these organisms is likely to have the largest genome? -a yeast cell -an extremophile Archaean due to the demands of surviving in harsh environments -an autotrophic bacteriuma -chloroplast

-a yeast cell

Based on the following table of characteristics for each group, what would be the surest way to enrich purple nonsulfur bacteria from an environmental sample?

Providing mineral salts, organic carbon and light, but excluding fixed nitrogen and filling the gaseous headspace with N2.

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

false