BIOL 2420 Final

How many chromosomes are found in each bacterial cell?

46

Ribosomes associated with cells and organelles have a certain size and density, which is expressed in Svedberg units. Prokaryotes and mitochondria/chloroplasts of eukaryotes have what size ribosomes?

80S

Thymine base pairs with _______________?

Alanine

Identify which statement is false.

Algae have cellulose in their cell walls.

Bacteria whose optimal growth occurs around a pH of 7.0 are called?

Alkalophiles

What type of flagellar arrangement is depicted in this image?

Amphitrichous

Which type of vaccine is one where you get infected with a weakened but live microbe?

Attenuated

Lipid A in the outer membrane of this Gram negative organism is shown as Letter ______?

B

An organism with 80S and 70S ribosomes could be a?

Bacterium

Bacteria divide by a process called?

Binary fusion

The outer protein coat of a simple, nonenveloped virus particle is called a ?

Capsomere

Which staining procedure is designed for bacteria with high lipid content (mycolic acid) and resistant to standard staining techniques?

Capsule stain

The membranes of all the inclusions found in bacterial cells are made of __________________?

Carbohydrates

The most abundant molecule making up a membrane is the ?

Carbohydrates

The enzyme that assembles free nucleotides to make an RNA molecule during transcription is ?

DNA polymerase

Temperatures below that of optimal growth will cause a mesophile to:

Die quickly at high temperature

The body region where a mucociliary escalator helps to sweep microbes trapped in mucus away from that body site is the :

Digestive tract

Internal structures in bacterial cells that form small bodies of accumulated cellular materials.

Endospores

Animal viruses contain either DNA or RNA.

False

E. coli has no mitochondria.

False

Enzymes speed up reactions by lowering the activation energy of a reaction.

False

The first step to all viral infections is attachment of the virus to the specific host.

False

The presence of a viral envelope would make a virus more susceptible to chemicals such as alcohols.

False

Transcription occurs in the nucleus of eukaryotic cells and in the cytoplasm of prokaryotes.

False

A porin is represented by which letter in this diagram?

G

When performing a blood agar test in the lab, you discover that the colonies are surrounded by a clear zone. This is what type of reaction?

Gamma hemolysis

Which of the following causes artificially acquired active immunity?

Getting a cold

Which type of bacteria have LPS in their outer membranes?

Gram positive cells

Which type of T cell is responsible for apoptosis or programmed cell death of an infected host cell.

Helper T cells

Which antibody is most closely associated with allergic responses and reactions to parasitic worms?

IgD

Which antibody is a dimer found in secretions such as saliva and tears and is extremely abundant in the body?

IgE

Which antibody is a monomer found on the surface of B cell and involve in cell mediated immunity?

IgM

What activates the cell mediated response of the immune system?

Interferons

The bacterial growth phase where a maximal rate of cellular division is obtained:

Lag phase

Who is credited with discovering penicillin?

Louis Pasteur

Which type of bacteriophage attacks a host bacterium, reproduces and quickly lyses the host?

Lysogenic

Which type of bacteriophage infects a bacterial host, integrates into its DNA and is silently copied every time the bacterium divides.

Lytic

Which of the following not only reveals cell shape but also additional information about the specimen?

Negative Stain

A natural killer (NK) cell is what type of cell?

Neutrophil

Which type of media would be used to grow fastidious organisms that require defined (known) quantities of specific nutrients?

Nutrient broth

Which part of the LPS molecules serves an an endotoxin in Gram negative bacteria?

O antigen

Chemical substances such as histamine and leukotrienes trigger which process ?

Phagocytosis

Single celled eukaryotes that require a moist environment and move by using flagella, cilia or amoeboid motility are known as ?

Prokaryotes

Name the process of movement of bacteria toward or away from particular stimuli or toxic agents.

Pseudopods

Which type of bacteria would you find growing in a volcanic vent in the ocean floor?

Psychrophiles

Which enzyme is a hallmark feature of retroviruses (like HIV) and is also found in HBV (hepatitis B virus). [The enzyme produces dsDNA from ssRNA]

RNA polymerase

Which of the following is NOT a reason for entering stationary phase:

Reaching a critical population density.

If a virus is enveloped, its most likely method for entering host cells is ?

Receptor mediated endocytosis

This body region is protected by fatty acids, acidic pH, lactic acid, and a tough cell barrier with its own normal flora:

Respiratory tract

Who accidentally discovered the antimicrobial action of penicillin?

Richard Petri

Which of the following structures contains genes for enzymes and antibiotic resistance?

Sex Pilus

When are bacteria most susceptible to antibiotic therapy?

Stationary phase

The part of an endospore responsible for stabilizing DNA for a very long time is:

The spore coat

Phospholipds in a viral envelope often originate from ?

The virus makes the phospholipids

What do Rickettsias and Chlamydias have in common with viruses?

They are enveloped.

What do all organic compounds have in common?

They are good buffers.

When bacteriophages attack a bacterium and inject their DNA into the host cell, the lytic cycle begins. What happens to the empty phage capsids after they inject their DNA?

They leave to infect other cells

Uracil replaces __________________ in RNA.

Thymine

________________________ requires "competent" bacterial cells which have been treated so that they take up naked foreign DNA through their cell walls.

Transduction

____________________ occurs when DNA is directly transferred from one bacterium to another through the use of a sex pilus which connects the two cells directly.

Transformation

Transfer of genetic material from one bacterium to another by a bacteriophage is called _______________.

Translocation

Small, circular pieces of DNA which are free floating in bacterial cytoplasm and replicate independently of the bacterial chromosome are called ?

Transposons

Bacterial DNA is single stranded.

True

Fungi, algae, viruses and protozoa are all eukaryotes.

True

Introns are present in prokaryotic RNA.

True

Translation is the synthesis of protein from an rRNA template.

True

Which test tube demonstrates a positive citrate test using Simmon's citrate agar slants?

Tube A

Prions are ________________ which cause degenerative brain diseases.

Viroids

Look at the image of the Lysogenic Cycle for a bacteriophage below. In the bottom two cells, what do you call the viral DNA in RED?

a specialized transducing particle

Through feedback inhibition (noncompetitive inhibition), a noncompetitive inhibitor of enzyme activity would bind to the _______________ site of the enzyme and stop the reaction.

active

Formation of endospores:

allows bacterial reproduction

Brand new strains of the flu to which no one has immunity and which cause a pandemic are generated by ?

antigenic drift

Plaques are:

bacterial colonies on agar

Protection against high osmotic pressure is provided by the ________________ of bacterial cells.

capsule

All three of these tubes are glucose fermentation tubes inoculated with a bacterium which has been growing for 28 hours. How would you report the result for the tub on the left?

carbon dioxide only

In this bacterium with lophotrichous flagella, the cell also has short hairlike appendages covering its cell wall. What are these short hairlike structures which are used for attachment, not motility?

cilia

The main function of fimbriae is ?

conjugation

The DTaP vaccine protects against which infections?

diphtheria, tetanus and atypical pneumonia

The Gram stain is based on differences in the ________________ of bacterial cells.

endospores

When this streptococcus was stained in the lab, large white halos were visible around the bacteria which did not stain. What are these large white halos?

endospores

Only bacteria belong to this group.

eukaryotes

A student is asked by the professor to sub-culture a bacterial organism onto a fresh TSA slant for future studies. During the sub-culturing process, the student closes the cap on the tube tightly. After a couple of days in the incubator, the culture dies. What type of culture did the student have?

facultative anaerobe

The individual proteins making up the capsid of a virus are called ?

glycoprotein spikes

Fast swimming enterics, such as E. coli, are covered with _____________________ flagella.

lophotrichous

Nonspecific chemical defenses include:

lysozyme

The site of ATP synthesis in bacteria is the ?

mitochondria

Which would be the most immediate result of destruction or inhibition of a cell's ribosomes?

no ATP production

If E. coli is growing in a broth with lactose and sucrose, will the lac operon be on or off?

off

A ___________________ is a worldwide epidemic.

pandemic

In this endospore stain, what color are the endospores?

pink

Which of the following is the most important structure related to microbial attachment to host cells?

plasmid

Which of the following is not considered a microorganism?

protozoan

Gram positive bacteria stain what color in the Gram stain?

purple

A bacterial cell is said to be _______________ when its cell wall is permeable to foreign DNA.

receptive

Peptidoglycan:

regulates the netry and exit of materials through the cell wall via transport proteins

Blood agar is a ______________ medium. Most bacteria grow on blood agar. However, those that lyse red blood cells are distinguished by a clear zone around the bacterial colonies.

selective

What is the most likely source of a nosocomial infection?

sex

What would call the arrangement of this bacterium?

staphylococcus

If this were a really up close image of bacterial cells which had been Gram stained, what would you record as the arrangement of this organism?

streptococcus

The long branch like structures with spore sacs (sporangia) attached at the ends are called _________________.

thalli