Bio Test 3

Which of the following involves metabolic cooperation among prokaryotic cells?

-biofilms

Based on the gene map, which number is closest to the frequency of a-b+c+ transformants that you would expect from this experiment?

0.064%

Mean values can be calculated using the following formula: x¯=Σxinx¯=Σxin. In this formula, x i is the value of the ith observation of the treatment variable x, n is the number of total observations, and the ΣΣ symbol indicates that the n values of x are to be added together. Calculate the mean for each treatment.

9.1 8.4 5.3 7.2 4.7

Which of the following statements about phylogenetic trees is true?

A paraphyletic group consists of a common ancestor and some of its descendants.

Antibiotic-resistant bacteria are becoming an increasing problem. Some bacteria that were once killed by common antibiotics have acquired the ability to survive in the presence of those antibiotics. How can bacteria acquire antibiotic resistance?

Bacteria can gain an antibiotic-resistance gene by conjugating with another species of bacteria, bacteria can acquire random mutations that allow them to grow in the presence of antibiotics, bacteria can acquire antibiotic-resistance genes by becoming infected with a virus that contains an antibiotic-resistant gene & bacteria can pick up an antibiotic-resistance gene from the environment through transformation

Which of the following statements best represents the effectiveness of teixobactin and vancomycin in reducing the number of MRSA colonies relative to the control?

Both antibiotics substantially reduced the number of MRSA colonies compared to the control. Further, at both the 1 mg/kg and 5 mg/kg doses, there was no significant difference in the number of MRSA colonies, suggesting that teixobactin and vancomycin are equally effective at controlling MRSA.

Which statement about endotoxins is true?

Endotoxins are released only when bacteria die and their cell walls break down.

According to this phylogenetic tree, which of these pairs of prokaryotic subgroups share the most recent common ancestor?

Euryarchaeota ... Crenarchaeota

Which molecule did Carl Woese study to produce his tree of life?

Ribosomal RNA Submit

What conclusion can you draw from the data?

Some Rhizobium strains are much more effective at promoting plant growth than other strains; the most ineffective strains have little positive effect.

Based on your results in Part A, which of the following statements most appropriately reflects the relative effectiveness of the vancomycin treatment, teixobactin treatment, and the control?

Teixobactin reduced the number of MRSA colonies about as effectively as did vancomycin relative to the control.

What is the difference between an F+ donor and an Hfr donor?

The Hfr donor has an F factor integrated into its main chromosome, but the F+ donor does not. Submit

Which of the following is true of generalized bacteriophage transduction?

The bacteriophage packages fragments of bacterial DNA into new phage particles. Submit

Suppose conjugation occurs between an Hfr cell and an F- cell. Although not typical, what would have to occur for the recipient cell to become an Hfr cell?

The entire F factor would have to be incorporated into the recipient cell's chromosome.

What usually happens to the recipient cell following conjugation with an Hfr cell?

The recipient cell remains an F- cell.

What is the function of fimbriae

They are used to attach the cell to its substrate or to other prokaryotes.

How does the large amount of genetic variation observed in prokaryotes arise? See Concept 27.2

They have extremely short generation times and large populations they can exchange DNA with many types of prokaryotes by way of horizontal gene transfer.

True or false? Data showing that the Bacteria were the first lineage to diverge from the common ancestor of all living organisms suggest that the Archaea and Eukarya are more closely related to each other than they are to the Bacteria.

True

Drag the labels to their appropriate locations on the concept map below to explore the links between antibiotic resistance, binary fission, and conjugation.

a) antibiotics b) antibiotic resistance c) binary fission d)conjugation e) mutations f) DNA replication g) genetic recombination h) genetic variation

Fill in the gene map below based on these data.

a--c--------b--d

Bacteria that live around deep-sea, hot-water vents obtain energy by oxidizing inorganic hydrogen sulfide belched out by the vents. They use this energy to build organic molecules from carbon obtained from the carbon dioxide in seawater. These bacteria are _____. See Concept 27.3

chemoautotrophs

Organisms that can cause nongonococcal urethritis are classified with _____

chlamydias

Which of the following typically produces a recombinant F+ recipient cell?

conjugation between an F+ cell and an F- cell

distinguish between the three process of genetic transfer in bacteria

conjugation:-involves the transfer of DNA from an Hfr cell to an F⁻ cell requires cell-to-cell contact transduction:-involves bacteriophage transferring pieces of bacterial DNA from one cell to another transformation:-involves DNA from the environment being taken up into a bacterial cell All three:-involves recombination

The prokaryotic cells that were the first to add significant quantities of oxygen to Earth's atmosphere are classified as _____.

cyanobacteria

Plantlike photosynthesis that releases O2O2 occurs in

cyanobacteria.

Bacteria perform the following ecological roles. Which role typically does not involve symbiosis?

decomposer

The prokaryotic cells that built stromatolites are classified as _____.

e) cyanobacteria

The rapid reproduction and large population sizes of many bacterial populations mean that even a small mutation rate can lead to considerable ______________________

genetic variation

4. In theory, the two daughter cells are __________ each other and the parent cell.

genetically identical to

Streptococcus pyogenes is classified with _____.

gram-positive bacteria

The prokaryotic organisms most likely to be found living in salt ponds are the _____.

halophiles

Photoautotrophs use

light as an energy source and CO2 as a carbon source

Genetic variation in bacterial populations cannot result from

meiosis

However, mistakes made during DNA replication sometimes result in ________________, changes to the nucleotide sequence of DNA.

mutation

Genes for the resistance of antibiotics are usually located __________. See Concept 27.2

on plasmids

During binary fission, DNA replication begins at the _________________________________ and continues all the way around the circular chromosome.

origin of replication

When DNA replication is complete and the bacterium has reached twice its original size, the _______________________ grows inward, dividing the parent cell into two daughter cells.

plasma membrane

The chemoheterotroph Proteus vulgaris is a rod-shaped bacterium classified with _____.

proteobacteria

Spiral-shaped bacteria are likely to be placed with _____.

spirochetes

An ecological relationship between organisms of different species that are in direct contact can best be described as _____.

symbiotic

How are archaeans most similar to bacteria?

the shape of their chromosomes and plasmids

Bioremediation is _____.

the use of organisms to remove pollutants from the environment

What characteristics were used to classify organisms before Woese's tree of life analysis?

Presence of a membrane-bound nucleus

Which group was not described in Woese's tree of life analysis?

Prokarya

Which of the following statements is not true?

Only bacteria have histones associated with DNA.

What is lateral gene transfer?

Physical transfer of a gene from a species in one lineage to a species in another lineage.

Bacterial conjugationDrag each phrase into the appropriate bin depending on whether it applies to an F+ cell, an Hfr cell, or an F- cell. (Remember that we are only considering conjugation involving the F factor here, and not other mechanisms for transferring genetic material.)

F+ cell:1) carries the F factor in a plasmidmay2) may donate a plasmid to another cellHfr cell:1) carries the F factor in its circular chromosome2) may donate genes from its chromosome to another cellF- cell:1) may become F+ after conjugation with an F+ cell2) may become recombinant after conjugation with an Hfr cell3) may receive genetic material, but cannot donate genetic material

Binary fission is a form of ______________________________ because a single individual is the sole parent and passes copies of all its genes to its offspring.

asexual reproduction