Quiz 1

Which of the following specialized structures/inclusions would aquatic photoautotrophic bacteria likely possess? 1. Thylakoids 2. PHB Granules 3. Carboxysomes 4. Gas vacuoles 5. Chloroplasts

1, 3, 4

Bacteria carry out bidirectional replication of their single chromosome by using _____ replisomes that each contain _____ DNA polymerase enzymes.

2;2

Which of the following is true of viruses?

They are not considered cells.

Slow release of bacteriophage progeny from a bacterial host cell A. does not kill the host cell B. is a feature particular to filamentous phage C. causes cell lysis D. B and C are correct. E. A and B are correct.

A and B are correct.

A. The cell envelope material of Gram-positive bacteria contains endotoxin activity. B. The periplasmic space contains the peptidoglycan layer of Gram-negative bacteria. C. The structure/composition of the membrane lipids of Archaea are the same as in bacteria. D. In comparing the cell envelopes of Gram-negative bacteria and a Gram-positive bacteria, it would be accurate to say that Gram-positives have much more lipid material in their cell envelope than a Gram-negative. E. All the above are false statements, none are true.

All the above are false statements, none are true.

An ecosytem can be depicted by the simplified food chain shown; autotrophs form the foundation of the ecosystem, above them are different levels of heterotrophs (e.g., herbivores, carnivores). Heterotrophs and autotrophs both eventually become fodder for the decomposers that break down dead organic material. Among statements A, B, and C, which is false?

Autotrophs comprise only those types that can use light energy; i.e, photosynthesize.

Which statement below regarding membrane structure and membrane transport is true?

Cyclization of membrane phospholipid fatty acids (like cyclopropane) would confer more rigid, straighter hydrocarbon chains.

Which of the following statements among A-C is false? A. Mycobacteria species contain peptidoglycan in their cell envelope. B. For those Archaeal types that possess a cell wall, it is comprised of pseudomurien. C. Mycoplasma species of bacteria would very likely not be affected at all by the presence of penicillin or vancomycin.

D. None A-C are false, all the above are true.

Of the molecules listed in A - D, the least abundant molecule (based on % of total wt) in a prokaryote cell would be

DNA The least abundant molecule (based on % of total wt) in a prokaryote cell would be DNA. It forms 1% of the total wt of the prokaryotic cell.

Cytoskeleton element that determines the cell diameter and is required for proper cell division Yields a high quantity of polypeptide in a short time interval Is duplicated soon in the initial stageof DNA replication Attaches the peptidoglycan to the membrane in Gram-negative bacteria Cytoskeleton element found only in rod-shaped cells

Fts Z polysome Formation orisequence lipoprotein mreB

A second, outer membrane is found in

Gram-negative bacteria.

An environmental (soil) sample obtained from a temperate region was transferred to a liquid growth medium and incubated at 30°C for 24 hours, then transferred to solid growth medium in order to isolate bacteria from the original sample. Following 48 hour incubation at 30°C, the picture of the solid medium shows the results of this experiment. Which of the following statement(s) among A - D are true regarding this experiment?

I dentification of microbial types in the environmental sample could have been attempted without culturing anything.

Which one of the following pairs among A-D is mismatched? A. metachromatic granules - energy storage granule B. PHB inclusions - glucose storage product C. sulfur granules - product of phototrophic or lithotrophic bacteria D. gas vacuoles - flotation; depth adjustment E. None of A-D are mismatched; all are correctly matched

PHB inclusions - glucose storage product PHB inclusions contain Poly hydroxy butyrate and not glucose. Glucose is stored as glycogen

A cross-section of the cell envelope of two bacterial cells, A and B, are shown in the figure. Which label is matched with the correct structure?

Structure A: lipoprotein

Pasteur's work with the French wine industry proved all of the following, EXCEPT:

That microbes can cause disease.

Which of the following is true of prion diseases?

They lead to neurodegeneration.

A mixed culture does not necessarily indicate a contaminated culture.

True

Pathogen X has successfully been transmitted to your body; you are now infected. All of the following among A-D are possible consequences of this infection, EXCEPT:

WRONG You exhibit mild symptoms of disease and the levels of the pathogen in your body are quickly reduced and eliminated.

Which of the following statement/statements among A-E regarding microbes is/are false? Unculturable microbes have been revealed through metagenomics studies. B. Archaea is a type of eukaryotic unicellular microorganism that can live in extreme conditions. C. The evolution of cyanobacteria allowed for the later evolution of cells with an aerobic metabolism. D. Certain prokaryotes are autotrophs that can obtain energy from inorganic sources like iron (Fe2+), ammonium ions (NH4+), and hydrogen (H2). E. Though changes were made later, the Kingdom Protista was originally formed to contain all microorganisms.

WRONG two of the statements among A-E are false

The figure below shows Louis Pasteur and his swan-necked flask. This apparatus was used to show that

air (oxygen) does not allow spontaneous generation.

Which of the following among A-D is false regarding all types of viruses?

all viruses possess an envelope

Methanogens, thermophiles, and halophiles characterize many members of this taxonomic group of microbes

archea

An organism is classified as a heterotroph or autotroph based on the type of ________ it utilizes..

carbon source

Match the following descriptions with the correct term or structure Likely found in an autotroph H antigen counterclockwise rotation of flagella/flagellum PHB granule

carboxysome lps layer produces "runs" towards an attractant lipid storage

You analyze a sample of Martian soil and determine there are microscopic, unicellular organisms that possess a nucleus, cannot photosynthesize, and are heterotrophs. You can be reasonably certain that these are very similar to members of the:

fungi

Phage lambda lytic versus lysogenic phases are controlled by two proteins, Cro which leads to lysis and CII which leads to lysogeny. __________ nutrient concentrations in the gut promote E. coli production of proteases that cleave __________ and activate __________.

low; Cro; lysogeny

A _____ virus cycle leads only to cell lysis, and a _____ virus cycle involves phage genome integration into the host genome.

lytic; lysogenic

In the CRISPR system of bacteria, the spacer is a(n):

piece of phage DNA

Viroids lack

proteins bitch

The viral capsid comprises

proteins.

The choices below each list three groups of organisms. For which choice, do all three groups have members that are considered microbes and are not a functional part of a multicellular organism?

protozoans, fungi, bacteria

The Baltimore classification of viruses is based on the the composition of the viral genome and

the host range of the virus.

In the plaque assay for bacteriophages,

the plaque is a clear zone caused by a zone of lysis.

Polysome formation in bacteria is able to occur because _________________.

they lack a nuclear membrane

Within a host, receptor molecules can also determine the __________, or tendency to infect a particular tissue type.

tropism

Which of the following scenarios represents a situation where a suspected disease-causing microbewould not be consistent with one or more of Koch's postulates? Injection of the microbe into an animal host does not produce disease symptoms. Some healthy individuals possess the microbe.

two of the above

Genes for the capsid proteins are found in the:

viral genome

The host range of a virus is determined by

whether the glycoproteins or capsid proteins on its surface recognize those of the host cells.