MB lab final

What type of microscope will be used in MB230 class?

a) simple
b) complex
c) compound
d) electron

A compound microscope uses only one type of lens

T/F

Which of the following objective lens you should use in case of oil immersion?

a) 4x
b) 10x
c) 40x
d) 100x

To observe a wet mount slide, which objective lens should not be used?

a) 4x
b) 10x
c) 40x
d) 100x

Which one of the following is not true regarding the wet mount slides?

a) one can observe the live microorganisms
b) slide preparation is quicker
c) Slides can be only observed by 10x or 40x objective lens
d) slides can be used for long period of time

To focus a sample under a microscope, one should use the lower objectives first.

T/F

What should be done before putting the microscope away?

a) Clean off the oil from the 100x objective
b) Store microscope with low power or blank objective
c) Wrap the cord around oculars
d) Have your TA to check the microscope
e) All of these

Microorganisms can grow in air

T/F

In exercise 2 (Microorganisms in the air), what type of nutrient medium you will use?

a) Plate count agar (PCA)
b) Trypticase Soy Agar (TSA)
c) Nutrient agar (NA)
d) None of these

What is the sterilized condition inside an autoclave?

a) 115 C and 21 pounds/in
b) 121 C and 15 pounds
c) 115 C 21 pounds
d) 100 C and 21 pounds

You need to label your petri plate on the agar side

T/F

Agar plates should be incubated agar side down

T/F

A single dye is being used in simple stain method

T/F?

Bacterial cells are positively charged

T/F?

The dye of the simple stain combines with the bacterial cells due to the difference in-

a) Charge
b) pH
c) Color
d) Concentration

Which of the following is not the general shape of the bacteria?

a) Coccus
b) bacillus
c) Spiral
d) Irregular

Rod-shaped bacteria are also known as cocci.

T/F?

To prepare a slide of bacterial culture, one should air dry before heat fixing?

T/F?

In microbiology, a pure culture is defined as a culture containing-

a) Only one microbial cell
b) Mixed microorganisms
c) Only one species of organism
d) Only one organism, but may contain different species

In microbiology, a single colony in an agar plate represents-

a) A single bacterial cell
b) A cluster of mixed bacterial cells
c) A cluster of cells that originate from a single bacterial cell
d) A cluster of mixed bacterial cells that originate from a single bacterial cell

Which of the following is the correct measure one should follow to maintain the proper aseptic technique?

a) Removing petri plate lids completely
b) Sterilize the inoculating loop or needle by heating before and after each transfer
c) Touching bacterial culture with non-sterile object
d) place test tube caps and petri plate lids on the counter

RODAC plates can only be used on flat, impervious surfaces

T/F

All types of microorganisms can grow on RODAC plate

T/F

What type of diluent is generally used in swab culture technique?

a) Distilled
b) Salt solution
c) Phosphate buffered saline
d) nutrient broth

Differential staining can be used to observe-

a) The bacterial cell wall type
b) The presence of capsules
c) The presence of spores
d) All of these

Gram-stain is being used to differentiate the bacteria based on their cell wall structure

T/F?

Which of the following is correct?

a) Gram-positive bacteria have thick layer of peptidoglycan

b) Gram-positive bacteria have thin layer of peptidoglycan

c) Gram-negative have thick layer of peptidoglycan

d) Gram-positive bacteria have outer lipid membran

Which of the following is the correct order (left to right) of reagents to be applied in Gram staining procedure?

a) Safranine⇒Iodine⇒Acetone-alcohol⇒Crystal violet

b) Safranine⇒Acetone-alcohol⇒Iodine⇒Crystal violet

c) Crystal violet⇒Acetone-alcohol⇒Iodine⇒Safranine
Correct!

d)Crystal violet⇒Iodine⇒Acetone-alcohol⇒Safranine

Iodine is also known as mordant in Gram-stain technique

T/F?

Safranin is also known as counter stain in Gram-stain technique

T/F

In Gram-staining technique, the final color of the Gram-positive bacteria will be-

a) Purple
b) Pink
c) Green
d) Yellow

In Gram-staining technique, the final color of the Gram-negative bacteria will be-

a) Purple
b) Pink
c) Green
d) Yellow

What is/are reason/s for differential Gram-reaction?

a) Improper heat fixing
b) Thick bacterial smear
c) Improper decolorization
d) Old bacterial culture
e) All of these

If you apply too much acetone-alcohol during Gram-stain procedure, what would be the likely outcome? (You may choose more than one answer to get points for this question).

a) Gram-positive bacteria will appear as Gram-positive

b) Gram-positive bacteria will appear as Gram-negative

c) Gram-negative bacteria will appear as Gram-positive

d) Gram-negative bacteria will appear as Gram-negative

By observing the Gram-stain slide of a bacterial culture, one can observe both bacterial morphology and the cell wall type

T/F?

Plants can directly utilize atmospheric inorganic nitrogen

T/F?

Which of the following plant is not considered as legumes?

a) Peas
b) Oregano
c) Clover
d) Alfalfa

What type of relationship is present between legumes and Rhizobium species?

a) Symbiotic
b) Opportunistic
c) Pathogenic
d) Neutralism

Which of the following statement is not true about nodules?

a) Nodules are one kind of enlarged sections of roots
b) Nodules are present in all plants
c) Nodules are induced by the Rhizobium infection in plants
d) Bacteroids are present inside the nodules

Which of the following is correct about Rhizobium sp.?

a) Nitrogen- fixing bacteria
b) Convert atmospheric N2 into organic nitrogen
c) develop bacteroids inside the root nodules
d) all of these

Bacteriophages are-

a) bacteria
b) Virus
c) Fungi
d) Protozoa

Which of the following is the correct order of events in a bacteriophage infection?

a) Attachment=>Entry=> Synthesis=> Assembly=> Release

b)
Entry=>Attachment=>Synthesis=>Assembly=>Release

c) Synthesis=>Assembly=>Attachment=>Entry=>Release

d) Attachment=>Synthesis=>Entry=>Assembly=>Release

Which of the following is the correct unit for bacteriophage counting?

a) Colony forming unit per milliliter (CFU/ml)
b) Plaque forming unit per milliliter (PFU/ml)
c) Spore forming unit per milliliter (SPU/ml)
d) Plaques per milliliter

Plaques are actually-

a) The confluent lawn of bacterial growth
b) The confident law of viral growth
c) The clear zone within the bacterial growth
d) The clear zone within the viral growth

What is the statistically significant plaque range in an agar plate to achieve the most accurate estimation?

a) 15-100
b) 15-150
c) 25-200
d) 25-250

What type of plating method will be used for plaque count?

a) Streak plate
b) Spread plate
c) Pour plate
d) None of these

Agrobaterium tumefaciens is the causative agent of crown gall disease.

T/F?

Gall formation is one type of tumor formation in plants

T/F?

What type of plasmid does Agrobaterium tumefaciens possess?

a) F-plasmid
b) Ti-plasmid
c) R-plasmid
d) K-plasmid

What is the main purpose of Koch's postulates?

a) To identify the factors that is associated with particular disease
b) To identify a particular microorganism that is associated with particular disease
c) To identify a particular hose that is associated with particular disease
d) To identify a particular disease that is associated with another particular disase

Which of the following agar plate will be used for the isolation of Agrobacterium tumefaciencs in this class?

a) PCA plate
b) TSA plate
c) MGY plate
d) NA plate

Anaerobic bacteria can grow in presence of oxygen

T/F?

Facultative bacteria can grow both in aerobic and anaerobic condition

T/F?

Resazurin dye is being used in sodium thioglycollate broth to indicate the presence of O2. Which of the following statement is correct about this dye?

a) Dye is colorless in presence of O2
b) Dye is pink in presence of O2
c) Dye is pink in absence of O2
d) Dye is always pink

In exercise 10, the labeling should be done-

a) On the glass portion of the tube
b) On the cap of the tube
c) On a separate paper/tape
d) Labeling not required

You should use a/an ___ to inoculate the bacteria in sodium thioglycollate broth

a) Inoculation loop
b) Inoculation needle
c) Syringe
d) Pipette

The mouth is very hostile environment for microbial growth.

T/F

All microorganisms inside the mouth can grow on agar plate

T/F

Which of the following group of bacteria is predominant inside the mouth?

a) Streptococcus spp
b) Staphylococcus spp
c) Bacillus spp

Which of the following group of bacteria is predominant inside the throat?

a) Streptococcus spp
b) Staphylococcus spp
c) Bacillus spp

Streptococcus mutans is the predominant species on the tongue.

T/F?

Which of the following bacteria can metabolize sugar?

a) Streptococcus mutans
b) Streptococcus salivaris
c) Streptococcus sanguis
d) All of these

Which of the following statement is not true about dental plaque?

a) It contains bacteria, salivary debris and glucan
b) It can wash away with saliva
c) It can lead to cavities
d) It is initially formed by the production of glucan

Glucan is mainly composed of long chain of _____ .

a) glucoses
b) fructoses
c) sucroses

Which of the following agar plate will be used in the class to identify the mouth organisms?

a) Nutrient Agar (NA)
b) Blood agar (BA)
c) Sucrose agar plate
d) Tryptic Soy agar (TSA)

Which of the following agar plate will be used in the class to identify the throat organisms?

a) Nutrient Agar (NA)
b) Blood agar (BA)
c) Sucrose agar plate
d) Tryptic Soy agar (TSA)

Match the correct hemolysis from the right column.

Alpha Hemolysis-
Beta Hemolysis-
Gamma Hemolysis-

(Fill in the blank)
Pathogenic bacteria are responsible to cause ____ hemolysis

Which of the following bacteria is considered as pathogenic bacteria?

a) Streptococcus pyogenes
b)Streptococcus salivarius
c) Streptococcus mutans
d) All of the above

In exercise 11 (microbes of the mouth) and 12 (Normal throat culture) , what type of plating method will be used?

a) Streak palte
b) spread plate
c) Pour plate
d) No plating required

Which of the following statement is not correct about indicator organism?

a) It is difficult to grow in the lab
b) It represents the presence of pathogenic bacteria
c) It dies at the same rate as pathogens
d) It contains the coliform bacteria

Fill in the blank

Coliforms are Gram _____ bacteria that ferment _______ and produce gas at ____ degrees celcius

Coliforms are facultative organisms. What does it mean?

a) They grow only in presence of O2
b) They grow only in absence of O2
c) They can grow in presence and absence of O2

Which of the following medium generally being used to primarily detect the coliform bacteria?

a) EMB agar
b) FTG broth
c) EC+MUG broth
d) LT broth

Durham tubes are being used in the nutrient broth to detect the-

a) Toxin production by bacteria
b) Gas production by bacteria
c) Acid production by bacteria
d) Alcohol production by bacteria

Escherichia coli is considered as fecal coliform as well as coliform bacteria.

T/F?

Conjugation is the only mechanism by which bacterial genetic material can be transferred between cells or strains.

T/F?

Conjugation involves direct transfer of genetic material from one bacterium to another.

T/F?

Which of the following is not correct about the plasmid?

a) extra chromosomal
b) Linear
c) Self-replicating
d) Transferrable

F+ strain refers to the recipient strain.

T/F?

Bacterial chromosomal DNA is transferred from one bacterial strain to another by conjugation.

T/F?

Sex pilus is formed by the donor strain.

T/F?

How long the donor and recipient strains need to be stayed together before plating on the agar plate in Exercise 14?

a) 10 min
b) 20 min
c) 30 min
d) 40 min

Conjugation between F+ and F- cells results in-

a) Two F- cells
b) F- cells becomes F+
c) F- cells remain F- cells with a little DNA from F+ cell
d) Remains same without any change

The gas production in LT broth indicates the same contains-

a) only coliform bacteria
b) only fecal coliform bacteria
c) coliform and fecal coliform or either one of these
d) non-coliform bacteria

Coliform and fecal coliform can be differentiated by the use of-

A) LT broth
B) EMB agar
C) EC+MUG broth
D) B+C

EMB agar inhibits Gram-positive bacteria because it contains

a) Eosin dye
b) Methylene blue dye
c) Combination of eosin and methylene blue dyes
d) None of these

What color will appear on EMB agar if the sample contains fecal coliform?

a) Pink
b) dark blue
c) Orange
d) Green metallic

Which of the following is not correct about Staphylococcus aureus?

a) S. aureus is one of the most common food-borne pathogen

b) S. aureus cause food poisoning regardless of the strains

c) S. aureus strains that produce enterotoxin cause food poisoning

d) S. aureus is the normal flora of our external body parts

Staphylococcus aureus grows faster in a condition that has-

a) warm temperature
b) High protein
c) High salt concentration
d) All of the above

What actually causes the Staphylococcus aureus food-poisoning?

a) Bacterial spores
b) Bacterial enterotoxin
c) Bacterial endotoxin
d) Bacteria only

Heat can destroy bacterial cells as well as subsequently inactivate Staphylococcal toxin.

T/F?

In exercise 15, you should use unsanitary condition to prepare potato salad.

T/F?

Fill in the blank

The main purpose of Exercise 15 is to determine the number of ________ in potato salad.

Which of the following order of metabolic process microorganism generally use to breakdown carbohydrate molecules?

a) Glycolysis > Fermentation/respiration > Enzymatic degradation

b) Enzymatic degradation > Glycolysis > Fermentation/respiration

b) Fermentation/respiration > Glycolysis > Enzymatic degradation

d) Glycolysis > Enzymatic degradation > Fermentation/respiration

Bacterial fermentation generally results in the production of-

a) Organic acids
b) Alcohols
c) gases
d) all of these

Aerobic respiration produces more energy (ATP) than fermentation process in the process of bacterial metabolism.

T/F?

What end result we can obtain by performing the Exercise 16 (Metabolism and Fermentation) ?

a) acid formation
b) gas production
c) Both or either one of these
d) None of these

Which of the following pH indicator is used in BCP broth?

a) Phenol red
b) Bromocresol blue
c) Bromocresol purple
d) Malachite green

Fill in the blank
At acidic pH, BCP broth turns into ______ color.

Mannitol salt agar (MSA) comprised of-

a) Mannitol
b) Salt
c) Phenol red
d) All of these

What will be the color of the agar is Staphylococcus aureus grows on MSA plate?

a) Pink
b) Red
c) Yellow
d) White

If 1 gm of food sample was added into 99 ml of diluent, then what will be the dilution factor for the food sample?

a) 10 dilution
b) 10 ^2 dilution
c) 10^3 dilution
d) 10^4 dilution

How many 10 fold serial dilutions are needed to achieve 10^5 dilution from 10^2 dilution?

a) 1
b) 2
c) 3
d) 4

Lactic acid bacteria ferment carbohydrates to produce ______ acid.

Fill in the blank

In the process of yogurt production, the pH of the milk rises.

T/F?

Ripening agents used in the production of cheese are actually-

a) Enzyme
b) Microorganism
c) Milk
d) cheese

The taste and the texture are different among the cheeses due to-

a) The use of different ripening agents
b) Length of ripening period
c) Conditions of ripening period
d) All of these

The pH of the yogurt drops due to the production of the ____ by bacteria.

Fill in the blank

The blue veins of the cheese are made of-

a) Mold spores
b) Bacterial spores
c) air circulation
d) bacterial culture

Which of the following is not the lactic acid bacteria?

a) Streptococcus thermophiles
b) Lactococcus bulgaricus
c) Lactococcus lactis
d) Penicillium roqueforti

Which of the following is not correct about fungi?

a) Non-motile
b) Do not have chlorophyll
c) Prokaryotes
d) Have distinct cell wall

Molds are different than yeast because they have-

a) Hyphae
b) Spores
c) Conidia or sporangia
d) All of these

Yeasts are multicellular organisms.

T/F?

Which of the following is not the correct example of molds?

a) Aspergillus sp.
b) Penicillium sp.
c) Rhizopus sp.
d) Saccharomyces sp.