MOLBIO - PRELIM Flashcards
What biosafety level is exclusive for primary health services, diagnostic services, research?
Basic Biosafety Level 2
What is the ideal depth of the pipet tip to the solution?
1 to 3mm
In what circumstances you will manually input the pH in the pH meter?
If the temperature differs from the standard room temperature
Which of the following separates the DNA strands in RNA synthesis?
Sigma subunit of RNA polymerase
Determine the molarity for 98000 mg of phosphoric acid, H3PO4, in 2.00 L of solution (MW=97.994 g/mol)
0.5 M
Development of In – situ hybridization technique is contributed to:
Mary – Lou Pardue and Joseph Gal
Which of the following biosafety cabinet provides the worker the highest protection?
Class III
Which of the following technique does not need electrophoresis
Dot blot
Which of the following solutions is NOT used in cleaning the pH electrode probe?
Concentrated NaOH
Which of the following statement is INCORRECT about Absorbance?
It is directly proportional to the transmitted light logarithm.
Universal/ Standard Precautions require that
Blood and body fluids from all patients be considered infectious
A substance that inhibits the growth and development of microorganisms without necessarily killing them
Antiseptic
Which of the following definitions best describes disinfection?
The use of antimicrobial agents on inanimate objects to destroy all non-spore- forming organisms
It is used to purify the granulocytes in the Ficoll-Directed Gradient Extraction
Ammonium chloride
The following are examples of Personal Protective Equipment EXCEPT:
Prescription glasses
Absorbance is also known as?
Optical density
Blotting technique for macromolecules that uses electric current is:
Western blotting
What is the volume capacity of P20 pipet?
2 to 20 ul
Once the liquid is removed from the DNA how can it be stored for years?
Keep in freezer
What bond does RNases break to degrade RNA?
Phosphodiester bond
The containment principles, technologies and practices that are implemented to prevent the intentional exposure to pathogens and toxin, or their intentional release
Biosecurity
Immediate information concerning the health hazards, flammability, and reactivity of a chemical can be obtained from the
NFPA symbol
Assurance that the sensitive and valuable information stored in a laboratory is protected from theft
Information security
It is a chaotropic agent used in protein degradation
Guanidinium thiocyanate
What is the role of protease in DNA extraction?
Used to break polypeptides to small fragments
Which of the following is in the correct order regarding DNA extraction?
Cell lysis; RNAase treatment; protease treatment &; ethanol precipitation
pH value is temperature dependent.
TRUE
The HEPA filters in a BSC filter particulate to size () and are () efficient.
0.3µm, 99.97%
To decontaminate Class I and Class II cabinets, this method should be utilized
Fumigation with formaldehyde gas
Sample problem: If O.D. at 260 is 0.30 nm
O.D at 280 is 0.45 nm Dilution factor is 100. Compute for dsDNA concentration.
1500 ug per ml
Example of RNase inhibitors
DEPC
Termination of transcription is facilitated by
Rho factor
It is used to digest the cell walls of fungal cells
Zymolyase
Double door entry is found in
BSL-3 and BSL-4
Which of the following is NOT a step in DNA replication?
Splicing
Adenine forms a covalent bond with a nucleic acid sugar at
N9
This is considered as the backbone of Biosafety
Risk assessment
Which substance was used to break down the phospholipids from the cell membrane and nuclear membrane?
Soap
What substance can cause the DNA to precipitate?
Ethanol
During electrophoresis, denaturation of the double stranded DNA molecule is brought by:
Treatment with alkali
How many grams would you prepare in 100ml of a 7.5% (w/v) solution of NaCl?
7.5g
If the ratio between OD 260 and OD 280 is
0.63 what does that tell us?
The sample is contaminated with other proteins
What is the purpose of adding Proteinase K in FFPE?
To increase the DNA yield
Which of the following RNase inhibitors needs to be removed from final preparation?
DEPC
This equipment is used to accurately measure and dispense small volumes of liquid
Pipettors
What is the main difference between RNA and DNA?
RNA has ribose DNA has deoxyribose
When does splicing occur?
Following pre-mRNA transcription in the nucleus
Which of the following is the basis for Western blot?
Antigen – Antibody reaction
Which of the following practices should be utilized when working in a biological safety cabinet?
Allow the BSC to operate before work begins and after work ceases
It is the most effective and reliable means to sterilize laboratory materials and decontaminate waste materials
Steam under pressure
What is the importance of magnetic beads in RNA extraction?
RNA binding
What is the next step after the addition of Elution buffer?
Add TE buffer
Why Bunsen burner must not be used in the biosafety cabinet?
The heat produced will distort the airflow and may damage filters
Sample problem: If O.D. at 260 is 0.30 nm
O.D at 280 is 0.45 nm Dilution factor is 100. Check for the contamination.
0.67 nm
Which of the following biosafety cabinet does not have HEPA filtered supply air?
Class I
RNA molecules that carry amino acids to the ribosome
tRNA
Dilute 150mL of 10X TBE buffer stock to 1.5L with deionized water.
1X
What level of biosafety practice Good Microbiological Techniques plus protective clothing only?
BSL 1
The following terminate protein synthesis EXCEPT
UGG
Which of the following is FALSE for RNases?
Preserve RNA in the sample
Southern blotting is a techniques used to:
Identify specific DNA
Equipment used in Molecular Biology to visualize DNAs and proteins
UV transilluminator
What is the tool that we used to measure pH in our laboratory activity?
pH meter
In reagent preparation activity, what instrument is used to measure the weight of the chemicals?
Analytical balance
Which of the following statement/s is/are true regarding Southern blotting?
-Developed by Dr. Edwin Southern
-DNA – DNA hybridization is the basis
-Transfer of DNA fragments from gel to nitrocellulose membrane is done
TRUE for handling and storage of Biological waste
Must be placed in a bag marked with biohazard symbol
How many ml of a 2.50M NaOH solution are required to make 525ml of a 1.50M NaOH solution?
315ml
Which of the following is NOT a function of nucleic acid?
They distribute protein all throughout the body
Filters generally used in biological safety cabinet to protect the laboratory worker from particulates and aerosols generated by microbiology manipulations are
HEPA
Autoclave temperature
121°C
ALL pipets have volume adjustment knob.
FALSE
Calculate the molarity of 500ml of 1.9 x 10^-6moles of NaCN in a
0.0000038 M
What does DNA stand for?
Deoxyribonucleic acid
A microorganism that is unlikely to cause human or animal disease
Risk Group 1
Labelled antibodies are used to detect:
Presence of a particular Protein molecule in Western Blot
Which of the following statements is FALSE?
Pipetting of BSL-3 materials should be done in an open bench top
How many grams of sodium chloride are needed to prepare 1L of 0.9% normal saline?
9
DNAs are found in a prokaryotic cell.
TRUE
It is a multifaceted cellular response in which more than 40 genes are induces when DNA is damaged
SOS repair
The first step in this technique is to depress the plunger down to 1st stop.
Forward pipetting
Which of the following is neutral pH?
7.00
Where does protein synthesis takes place?
Ribosome
In the final step of purification, DNA is rehydrated with what type of buffer?
Tris-EDTA
A technologist spilled 10 gallons of formaldehyde on the floor. After determining the chemical poses a significant health hazard, the first action step would be to:
Evacuate the area
The first step in this technique is to depress the plunger down to 2nd stop.
Reverse pipetting
Which of the following appears as a film of debris at the interphase after centrifugation of Organic Extraction Method?
DNA
Which of the following is not true for TRIzol?
used for purification step
The principle of capillary transfer is applied in which technique?
Northern Blot
Which of the following is INCORRECT when it comes to PH meter handling?
2 point calibration is better that 3 point calibration
After centrifugation, it is the solid form found at the bottom of the container
Precipitate
For a safe operation of a centrifuge:
Ensure proper balance is maintained
This type of extraction relies on the adsorption of nucleic acids to the solid phase
Minicolumn purification
In Western blotting:
Polyacrylamide gel is commonly used
When the hand is visibly soiled, it is recommended to decontaminate the hands with
Soap and water
Which of the following steps is arranged accordingly?
Mix solution to be measured; Remove electrode from storage buffer solution; Wash the electrode with distilled water
A solution is 0.2500M H2SO4. Calculate the volume in ml present in a sample of the solution that contains 0.005216moles of sulfuric acid
20.864ml
What is the volume capacity of P1000 pipet?
200 to 1000 ul
Which of the following does not describe Guanidine thiocyanate-phenol-chloroform extraction?
DNA molecules and proteins remain in the upper layer of the tube
