mcb 100 exam 2 practice

Which of the following is least likely to colonize the small intestine of chickens?

non-fimbriated and non-flagellated strains of Campylobacter jejuni

Which of the following cellular components do Gram-negative, but not Gram-positive bacteria have?

lipopolysaccharide (LPS)

The best way to prevent infection due to listeriosis is to

only eat or drink pasteurized dairy products.

Which biological process often occurs in animal (eukaryotic) viruses, but rarely occurs in prokaryotio viruses (phages)?

Virion release through budding from the host cell plasma membrane.

Which type of nucleic acid genome is not found in viruses?

circular, double stranded RNA/DNA hybrid

Coronaviruses are unique from most other RNA viruses because they assemble their virions at the mammalian host's endoplasmic reticulum before trafficking through the. released from the infected cell.

Golgi apparatus

Which of the following eukaryotic microbes is transmitted by insects?

Plasmodium

The organelle that spirochetes use to propel themselves is ____

cilia

Your friend has just told you that they are pregnant. You also know that they have two pet cats. What potential disease and the corresponding disease-causing microbe should your friend be worried about getting from having cats as pets?

miscarriage of the fetus caused by inhaling Toxoplasma gondii.

The polysaccharide found in the cell walls of red algae that is used as a solidifying agent in petri dishes is

agar

Which step of the virus replication cycle can be conducted by retroviruses (e.g., HIV) and lysogenic bacteriophages (e.g., phage lambda), but not lytic bacteriophages (e.g., T4 bacteriophage)?

Integration

Which of the following microbes are known to produce methane?

Methanosarcina

Which of the following help some thermophilic Archaea thrive in a hot spring?

Having membrane lipids that use ether-linkages to avoid hydrolysis at high temperatures.

Which one of the microbes below exhibits filamentous morphology?

B

Which of the following microbes does NOT have conidia?

Tetrahymena

Which of the following culture tubes most likely contains a methanogen?

B

Which protist is a concern because it can contaminate water sources and cause diarrheal illness?

Giardia

Which of the following proteins would be found in both coronavirus and HIV virions?

Reverse transcriptase

Opportunistic bacteria that can be pathogens in some people

always have two forms that switch when outside or inside the body.

Which of the following statements about HIV is true?

The virus RNA genome is reverse transcribed and integrates into the host genomic DNA.

Listeria monocytogenes is a common foodborne pathogen that can cause severe disease and is responsible for ~30% of all food related deaths in the USA. A mutation that results in the loss of the pore-forming listeriolysin O (LLO) protein would prevent which of the following aspects of the Listeria life cycle, thereby reducing the bacterium's virulence?

Escape from the phagosome into the cytosol where the bacteria could grow.

Identify the correct biological process occurring for each numbered step in the diagram of the retrovirus (HIV) lifecycle below.

1= Reverse Transcription, 2 = Translation, 3 = Transcription

____trap photosynthetic algae or cyanobacteria in a hyphael meshwork of ____ much needed carbohydrate nutrients for _____

Soredia | fungi | lichens

When viewed through a microscope, some fungi with branched hyphae look somewhat like plants.
Why are fungi not considered to be plants?

Fungi lack chloroplasts and therefore cannot perform photosynthesis like plants.

Which of the following statements best describes the entry step for bacteriophage replication during the lytic cycle?

Transfer of the phage genome into the host cell.

What is the approximate time required for synthesis of the virus depicted in the graph below?

4 weeks

Bacterial pathogens can acquire iron within the host by secreting  ____ lactoferrin that binds iron.

a toxin that pokes holes in host cell membranes.

Spore formation in gram-positive endospore-forming bacteria, like Bacillus and Clostridium, occurs in direct response to

depletion of an essential nutrient.

A T4 bacteriophage formed improperly while being produced by an infected cell. The virion had a capsid, genome, and tail, but no tail fibers. What is the first stage of the bacteriophage life cycle that would be blocked for this defective virus particle?

Attachment

Which of the following statements is NOT correct?

All Archaea produce methane.

The figure shown below is an image of
____, showing (A) ___ (B)____and (C) ____

mushrooms | fruiting bodies | fungal hyphae | mycelium

Which of the following statements most accurately explains the outcome of toxin action on host ells by a bacterial AB toxin that has a mutation that deletes its A part?

The toxin will be able to bind and enter the cell into endosomes, but it will not be able to deliver its catalytic cargo into the cytosol where it can cause its toxic effects.

Which of the following is more likely to cause infection of the stomach?

fimbriated and flagellated strains of Helicobacter pylori

Which of the following virulence factors do all Gram-positive, but not Gram-negative bacteria share?

LTA

The difference between fungi and algae is

algae have chloroplasts and so can undergo photosynthesis, while fungi do not.

Which of the following biological processes occur only in bacteriophages, but not animal (eukaryotic) viruses?

Virus attachment with tail fibers.

Coronaviruses are unique from most other RNA viruses because they assemble their virions at the hosts ____ before trafficking through the Golgi apparatus to be released from the infected cell

endoplasmic reticulum

Which type of nucleic acid genome is not found in viruses?

DNA-RNA Hybrid

Which of the following pairs of pathogenic microbes are both transmitted by insects?

Leischmania donovani and Plasmodium falciparum

Protozoa can survive changes in pH, nutrient availability or temperature as

cysts

A soldier stationed in Afghanistan might be more susceptible to

leischmaniasis caused by being bitten by a sandfly.

Toxoplasma gondii is _____known for its specialized organelles that allows it to ____

an apicomplexan | penetrate host cells

Which step of the virus replication cycle can be conducted by retroviruses (e.g., HIV) and lysogenic bacteriophages (e.g., corynebacteriophage), but not lytic bacteriophages (e.g., T4)?

Integration

For which of the following pairs of microbes, do both produce endospores?

Bacillus and Clostridium

Which of the following microbes does NOT have conidia?

Treponema pallidum

Which of the following statements about viruses is incorrect?

Viruses can remain dormant inside host cells.

1. Viruses can respond to environmental stimuli through metabolic changes.

Which one of the microbes below exhibits Spirochete morphology?

C

Which of the following statements about parasitic infections is FALSE?

Trypanosoma brucei, the causative agent of sleeping sickness, is an invasive flagellate transmitted by bedbugs.

Which of the following diseases was eliminated in the Americas in the late 1970s?

Polio

Which of the following proteins is unique to retroviruses?

Reverse Transcriptase

Opportunistic bacteria that can be pathogens in some people

can have the same virulence factors as overt pathogenic bacteria, except they lack a way of penetrating into tissues to cause disease.

Which of the following processes will most likely result in a new influenza A strain that is very similar to the current seasonal strain?

Antigenic drift

Listeria monocytogenes is a common foodborne pathogen that can cause severe disease and is responsible for ~30% of all food related deaths in the USA. Which of the following aspects of the Listeria life-cycle allows it to avoid detection by the immune system?

Cell-to-cell intracellular spread using actin-based motility.

Algae or cyanobacteria provide much needed carbohydrate nutrients for

lichens

Which of the capillaries below contains a repellant?

D

Which of the following statements best describes the synthesis step for bacteriophage replication during the lytic cycle?

Using the host machinery to make the pieces of the phage

What is the burst time of the phage depicted in the graph below?

6 hours

Bacterial pathogens can acquire iron within the host by secreting

siderophores that bind iron.

For gram-positive endospore forming bacteria, like Bacillus and Clostridium, spore formation occurs in direct response to

starvation.

Which of the following steps is directly blocked in an animal virus with a deletion mutation in the spike glycoprotein?

attachment

Which of the following statements about Archaea and Eukaryotes is correct?

Archaea and Eukaryotes lack peptidoglycan.

Suppose you have two A-B type toxins, A-B and A'-B'. A-B binds specifically to intestinal epithelial cells and causes the cells to release water into the intestine. A'-B' binds specifically to muscle cells and stops protein synthesis that results in cell death. What would injection of a hybrid toxin, A-B', into the hind leg of an animal do to the animal?

Cause the leg's muscle cells to release water that causes the leg to swell

Which of the following statements most accurately explains the outcome on toxin action of a bacterial protein toxin that has a mutation that deletes its membrane-translocation domain?

The toxin wili be able to bit and enter the celi into endosomes, but it will not be able to deliver its catalytic cargo into the cytosol where it can cause its toxic effects.

Which of the following statements is correct?

Cyanobacteria have 70S ribosomes.

Which of the following eukaryotic microbes is transmitted by mosquitoes?

Plasmodium

A T4 bacteriophage has a mutation ni a capsid gene that resulted ni a truncated capsid protein being expressed by an infected bacterial cell. What is the first stage of the bacteriophage life cycle that would be blocked for this defective virus?

Assembly

Why are fungi not considered to be plants?

Fungi lack chloroplasts and therefore cannot perform photosynthesis like plants.

Spore formation ni Gram-positive endospore-forming bacteria, like Bacillus and Clostridium, occurs ni direct response to _

exposure to heat and desiccation.

Which of the following microbes has conidia?

Penicillium

Listeria monocytogenes is a common foodborne pathogen that is responsible for

~30% of all food related deaths in the USA. Amutation that results ni the loss of the ActA protein would prevent which of the following aspects of the Listeria life cycle, thereby reducing the bacterium's virulence?

Cell-to-cell intracellular spread using actin-based motility via comet tails.

Champaign and Chicago both ranked within the pest control company Orkin's top 10 bed bug cities for 2023. What potential disease and the corresponding disease-causing microbe si associated with bed bugs?

D. Chaga's disease caused by Trypanosoma cruzi

Which of the following steps of a viral life cycle is blocked by an antibody binding protein?

Binding of the virus to the host cell.

Which of the following traits helps some thermophilic archaea thrive in a hot spring?

Having proteins with more beta sheets that help increase protein stability.

Protozoans cycle between an actively motile and reproducing ___ form in the host and an infectious ___ form that can be found in the environment

trophozoite | cyst

Which protist is a concern because it can contaminate water sources and cause diarrheal illness?

Giardia

What is the approximate time that the virus depicted in the graph below is in its latent form?

4 weeks

Which of the following strains of the Gram-negative Campylobacter jejuni is the most likely to colonize the small intestine of chickens?

fimbriated and flagellated

Opportunistic yeast that can be pathogens in some people

1. can cause tissue damage like overt pathogenic bacteria, but they cannot enter body tissues.

Bacterial pathogens can acquire iron within the host by secreting.

a siderophore that binds iron.

Which of the following statements about influenza virus is true?

The virus genome consists of eight RNA gene segments.

Which one of the microbes shown below is most likely a spirochete?

Which of the following culture tubes most likely contains a facultative anaerobe?

C

The polysaccharide found in the cell walls of Rhodophyta red algae that is used as a solidifying agent in laboratory petri dishes is

agar

Which step of the virus replication cycle cannot be completed by lytic bacteriophages (e.g., T4 bacteriophage)?

Integration

Which of the following cellular components do Gram-positive, but not Gram-negative bacteria have?

lipoteichoic acid (LTA)

Identify the correct biological process occurring for each numbered step of the virus lifecycle shown in the diagram below.

1= Reverse Transcription, 2 = Transcription, 3 = Translation

Plaques are ____

clear areas on a lawn of cultured cells caused by virus infection.

The Lyme disease spirochete Borrelia moves through host tissues and cells by using its .

1. flagellum

Which of the following microbes is known to produce methane?

1. Methanococcus

Which biological process rarely occurs in prokaryotic viruses (phages)?

Virion release through budding from the host cell membrane.

The best way to prevent infection due to listeriosis caused by the psychrophile Listeria is to

avoid eating soft cheeses such as brie or cottage cheese.

Which of the following proteins would NOT be found in both coronavirus and HIV virions?

Reverse transcriptase

Which of the following statements most accurately explains the outcome of toxin action on host cells by a bacterial AB toxin with a mutation that deletes its membrane translocation domain?

1. The toxin will be able to bind and enter the cell into endosomes, but it will not be able to deliver its catalytic cargo into the cytosol where it can cause its toxic effects.

The figure shown below is an SEM image of ___, showing A___ B ___ C____

lichen | soredia in a phototrophic layer| algae | fungal hyphae