Test 3 - HW 5

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

Streptomyces are unique because

- most produce spores - they produce hyphae similar to fungi - some can produce antibiotics

Which of the following is an example of horizontal gene transfer in bacteria?

- transduction - conjugation - transformation

Determine why some prokaryotes have less DNA but more genes than eukaryotes

Eukaryotes have more introns in their chromosomes

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

Spirochetes have an unusual flagellum called an endoflagellum. How does it differ from other flagella?

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

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

Gas vesicles in cyanobacteria are used by the organisms for what purpose?

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

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

false

The ecological diversity of microbes is largely dependent on their complex morphological and structural diversity

false

The genome sequence of an organism can provide information about the organism's

genes, function, and evolutionary history

Aerobic methylotrophs are most likely to be found

in water and soil

A recombinant 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 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

What is the hallmark of all horizontal gene transfers?

transfer of DNA between organisms of the same generation

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

true

In a phylogeny, which two organisms would be most likely to be placed closest together after a node based only on the information given?

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

What is the primary difference between dissimilative sulfur reducers and dissimilative sulfur oxidizers?

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

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

a yeast cell

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

Which feature of Cyanobacteria contributes to their importance in shaping the Earth's atmosphere?

photosystem

Sequencing an organism's genome often leads to identification of hypothetical proteins, which are characterized as

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