LAB PP (1-7)

The image shows the result of a certain differential staining method that detects the presence of mycolic acid in a bacterial cell wall. Match the statement to the correct answer located in the drop down menu.

name of the staining technique

what color are positive bacteria stained

what color are negative bacteria stained

name the primary stain

name the counterstain

name of the staining technique

acid-fast stain

what color are positive bacteria stained

pinkish purple

what color are negative bacteria stained

blue

name the primary stain

carbolfuchsin

name the counterstain

methylene blue

What is the total magnification of a specimen if you are using a compound light microscope with the 40x objective lens?

400x

The image shows the result of a certain differential staining method that detects the presence of mycolic acid in a bacterial cell wall. What information can be concluded concerning the circled (blue) cells? [Be prepared to know information concerning the pinkish cells]

they are non acid-fast organisms that don't have mycolic acid in the cell wall

____________________ oil prevents the scattering of light when viewing a sample using the 100x objective lens.

immersion

A thick, detectable, discrete polysaccharide layer located outside of the cell wall that protects bacteria from the host's immune system and allow pathogens to invade the body is called a/an __________.

capsule

You are viewing a specimen using the 100x objective, but the image is fuzzy. Assuming that the microscope is clean and functioning properly, what is the likely reason why the image isn't clear?

forgot to use immersion oil

The image shows the results of a type of structural staining method called a negative stain that uses the dye, crystal violet. What are the purple colored structures depicted by the arrows? [Be prepared to identify the clear area surrounding the purple structures]

bacterial cells

When preparing a slide for bacterial staining, the _________________ step attaches the bacteria to the slide and kills the microorganisms.

heat fixing

Metabolically inactive (dormant) forms of bacteria that can survive harsh environmental conditions such as heat and UV radiation are called ____________.

endospores

The image shows the results of a staining method that differentiates between bacteria that have thick or thin layers of peptidoglycan in their cell walls. Match the statement to the correct answer located in the drop down menu.

name of the staining technique

what color are positive bacteria stained?

what color are negative bacteria stained?

name the primary stain

name the counterstain

name of the staining technique

Gram stain

what color are positive bacteria stained?

purple

what color are negative bacteria stained?

pinkish red

name the primary stain

crystal violet

name the counterstain

safranin

Lethal _____________-forming bacteria, such as Bacillus anthracis, can be used for bioterrorism.

endospore

The image shows the result of a differential staining method called the Gram stain. What information can be concluded concerning the circled (blue) cells? [Be prepared to know information concerning the pinkish cells]

the cells are gram positive and have a thick layer of peptidoglycan

The image shows the results of a structural staining method that can used to detect certain structures that can be found in bacterial species such as Bacillus anthracis and Clostridium tetani. Match the statement to the correct answer located in the drop down menu.

name of the staining technique

what are the pink structures

what are the green structures

name the primary stain

name the counterstain

name of the staining technique

endospore stain

what are the pink structures

vegetative cells

what are the green structures

endospores

name the primary stain

malachite green

name the counterstain

safranin

You have a mixture of gram positive and gram negative cells in culture. You prepare a slide from the culture and gram stain it, but when observing the sample using oil immersion, all cells appear purple. What is the likely technical reason why only purple-colored cells are observed?

you forgot the decolorization step

You observe gram-negative cells that aren't spherical in shape, but instead are rod-shaped. Use the information and the dichotomous key to identify the microoorganism.

gram-negative bacilli

The two organelles that are theorized to have evolved from prokaryotic cells are ______________ and _________________.

mitchondria and chloroplasts

Organisms in domain _____________ are more closely genetically related to organisms in domain ___________ than domain _____________.

archaea; eukarya; bacteria

Organisms in the domain archaea have cell walls that possess _______________.

pseudopeptidoglycan

Many extremophiles such as halophiles, thermophiles, and acidophiles belong to domain _______________.

archaea

What category of bacteria have cell walls that possess a thin peptidoglycan layer and lipopolysaccharide?

gram-negative

What category of bacteria have cell walls that possess a thick peptidoglycan layer?

gram-positive

Penicillin interferes with _____________ synthesis, so it is effective in killing gram-positive bacteria.

peptidoglycan

What category of bacteria is resistant to physical disruption and drying, but are highly susceptible to penicillin and anionic detergents?

gram-positive

Match the prokaryotic cell structure to the letter designation in the drop down menu.

nucleoid

plasma membrane

cell wall

fimbriae

nucleoid

G

plasma membrane

B

cell wall

C

fimbriae

D

What step of binary fission is occurring in step 1? [Know all steps in binary fission for upcoming exams]

DNA replication

Prokaryotes reproduce asexually mainly by a process called ____________.

Binary fission

Which letter-designated bacterial shape/arrangement is considered palisade? What is the shape of the bacteria labeled "G"?

F; vibrio

What is the shape and arrangement of the circled bacterial cells.

diplococci

The image shows the Gram stain results of a patient sample. What characteristics can you ascertain about the circled group of bacteria?

they are Gram positive staphylocci

A patient presents with nausea and diarrhea, and informs you that he was recently in Africa and drank water from a stream. Tests for various parasitic infections were negative, so the illness is likely caused by a bacterial infection. After further testing the patient is diagnosed with chlorea caused by the bacterium, Vibrio cholerae. Using the information ascertained from the bacteria's name, what shape do you think this organism is?

comma shaped

Match the eukaryotic cell structure to the letter designation in the drop down menu.

rough ER

smooth ER

centrioles

golgi appartatus

mitochondrion

rough ER

C

smooth ER

E

centrioles

I

golgi appartatus

K

mitochondrion

F

Prokaryotic and eukaryotic extrachromosomal DNA is called ______ DNA.

plasmid

Prokaryotic DNA is found in the __________ region and eukaryotic DNA is located in the ___________.

nucleoid, nucleus

Determine if the properties listed on the left-hand side column are describing DNA or RNA.

the sugar ribose

nucleotides A, U, C, G

used as a template for transcription

nucleotides A, T, C, G

translated to synthesize a polypeptide

the sugar deoxyribose

double stranded

single stranded

the sugar ribose

RNA

nucleotides A, U, C, G

RNA

used as a template for transcription

DNA

nucleotides A, T, C, G

DNA

translated to synthesize a polypeptide

RNA

the sugar deoxyribose

DNA

double stranded

DNA

single stranded

RNA

What mRNA sequence is synthesized using the DNA template strand AAT CCG AGG T?

UUA GGC UCC A

What type of RNA codes for proteins?

mRNA

What enzyme is necessary for transcription?

RNA polymerase

Eukaryotic mRNA have non-coding sequences called _______ that are spliced out before the RNA leaves the nucleus.

introns

Transcription occurs in the _________ of prokaryotes and the __________ of eukaryotes.

cytoplasm/nucleus

What is the anticodon sequence of a tRNA molecule for the mRNA codon UCA?

AGU

What type of RNA makes up a portion of the ribosome?

rRNA

The fact that more than one codon can code for a single amino acid is referred to __________ in the genetic code.

redundancy

What type of bond joins amino acids to a growing protein chain?

peptide bond

Which of the following is NOT a stop codon?

UGA

UAG

UAA

UGG

UGG

How many codon sequences code for the amino acid serine?

7

6

4

2

6

Translate the mRNA sequence ACA CAG AUG GUG CCC

threonine-glutamine-methionine-valine-proline

Sometimes during DNA replication a change in the DNA nucleotide sequence, which is called a mutation, can occur. There are various reasons why mutations occur. In certain instances, a chemical called _______ can increase the mutation rate.

a mutagen

There are two main types of mutations: base-substitution and frameshift mutations. Match the type of base substitution mutation located in the left-hand side column with the result of that mutation.

missense mutation

silent mutation

nonsense

missense mutation

a change in the wild type amino acid to a different amino acid

silent mutation

no change in the amino acid sequence

nonsense

premature stop codon introduced

If a nucleotide is inserted or deleted from the DNA sequence, the resulting mutation is known as a _________________ mutation.

frameshift

Thymine dimer mutations cause by ultraviolet light can be repaired using ___________.

photolyases and excision-repair enzymes

Mismatch-repair enzymes cannot repair a DNA mutation once it becomes ______________.

methylated

Which of the following characteristics doesn't describe viruses?

they don't have cells

they exhibit metabolism while outside of the host cell

they contain DNA or RNA

they are considered non-living

they exhibit metabolism while outside of the host cell

Which domain of life do viruses belong to?

viruses do not belong to any domain of life

Which of the following characteristics describe viruses?

they contain a nucleoid region

they are usually larger than bacteria

they are filterable (can pass through a filter)

they contain ribosomes

they are filterable (can pass through a filter)

Identify the icosahedral capsid. [Be prepared to to identify all labeled capsid shapes on upcoming exams]

b

A polyhedral virus that has 20 triangular-shaped sides are called ____________ viruses.

icosahedral

"Naked" viruses lack what structural component?

envelope

Viruses are surrounded by a protein capsid composed of individual subunits called ____________.

capsomeres

Which of the following is NOT a characteristic used to classify viruses?

nucleic acid type

capsid shape

presence/absence of an envelope

cell wall composition

cell wall composition

A ________ is an infectious viral particle that has yet infected its host's cells.

virion

Why are RNA viruses that use RNA-dependent RNA polymerase for transcription more likely to have genome mutations?

the enzyme doesn't have proofreading capabilities

Antigenic _________ occurs when advantageous mutations in viral genomes result in minor changes.

drift

Antigenic _________ occurs when there is a reassortment of genetic material from coinfecting viruses that produce a new viral strain.

shift

Which of the following is not a disease caused by prions?

Lou Gehrig's disease

Prions are misfolded ___________.

proteins

Mad cow disease is transmitted to humans by _______________________.

consuming contaminated beefq

The presence of specific ___________ on viruses determine whether it can infect a particular cell or not.

receptors

The first human virus was discovered in 1901. What scientist discovered the first human virus?

walter reed

Some scientists theorize that an ancient virus infected a bacterium helping it produce the first cell ___________.

nucleus

How do prion proteins create more prion proteins?

by catalyzing a conformation change in the wild type protein by direct contact with the prion

Which of the following abbreviations represent prion proteins?

A) PrPC

B) PrPSC

C) PrPMP

D) PrPP

B

Which of the following phases of bacterial growth doesn't match its description?

lag phase- intense activity preparing for growth and moderate increase in population

What are the nutrient requirements for an organism classified as a photoautotroph?

sun and CO2

Most extremophilic organisms belong to the domain __________.

archaea

__________ are moderate temperature-loving organisms that optimally grow at 25-40oC.

mesophiles

Many food spoilage bacteria are characterized by temperature as ___________.

psychotrophs

In what type of conditions would you expect to find a halophilic acidophile?

high salt and low pH

A certain species of bacteria grows the best on 25% glucose, 5% NaCl, and 0.2% magnesium sulfate agar plates. From this description, identify this general type of growth media.

chemically defined

A certain species of bacteria grows the best on 5% peptone, 5% beef heart extract, and 8% sodium chloride. From this description, identify this general type of growth media.

complex

The red arrows are pointing to _________________.

a single bacterial colony

This image shows the results of three different bacterial species grown on MacConkey media. Escherichia coli is a very strong lactose fermenter. Which letter likely indicates E. coli growth?

C

This image shows the results of three different bacterial species grown on EMB media. Escherichia coli is a very strong lactose fermenter. Which letter likely indicates E. coli growth?

C

The results in this image represent 4 different bacterial species inoculated onto an MSA plate. Which organism(s) is(are) halophilic acidophiles?

A and C

The results in this image represent 2 different bacterial species inoculated on an MSA plate. Which organism(s) ferment lactose?

there isn't enough information provided to answer the question

Streptococcus pneumoniae exhibits a greenish appearance when grown on sheep’s blood agar. What type of hemolytic pattern does this indicate?

alpha

Streptococcus pyogenes, the etiological agent of strep throat, scarlet fever and rheumatic fever, exhibits complete clearing of RBCs when grown on sheep’s blood agar. What type of hemolytic pattern does this indicate?

beta

Escherichia coli yields whitish colonies when grown on sheep’s blood agar. What type of hemolytic pattern does this indicate?

gamma

What is the rational of having a high salt content in the diagnostic media, MSA?

to select for halophiles and/or facultative halophiles

The selective & differential media called MAC contains a chemical called neutral red that will detect a change in pH if the sugar in the media is metabolized by the growing organism. What is the general term for the chemical added to media that detect changes in pH?

indicator

Sheep's blood agar differentiates between bacteria that produce a toxin called __________, which is indicated by the partial or complete destruction of red blood cells contained in the media.

hemolysin

When a sheep’s blood agar plate is streaked with bacteria, such as Streptococcus pyogenes, beta hemolysis occurs. What does beta-hemolysis indicate about the pathogenicity of S. pyogenes?

it is likely to be pathogenic

What occurs when a high-energy bond in ATP is broken resulting in ADP?

energy is released that will drive chemical reactions

During a redox reaction, the molecule that loses an electron is ______________ and the molecule that gains the electron is _______________.

oxidized/reduced

NADH and FADH2 play an important role in energy production by donating electrons for redox reactions that occur in the ___________.

ETC

Which process of glucose catabolism doesn't generate ATP?

intermediate step

The majority of the high-energy coenzymes (such as NADH and FADH2) are generated during

Kreb's cycle

Where does glycolysis occur in prokaryotes and eukaryotes?

cytoplasm

How many pyruvic acid molecules are produced from the glycolysis of 1 glucose molecule?

2

How many acetyl CoA molecules are produced during the intermediate step from 1 molecule of glucose?

2

What type of phosphorylation is used to produce ATP in the Krebs cycle?

substrate-level phosphorylation