1. Scientists developed a set of guidelines to address the safety of DNA technology. Which of the following is one of the adopted safety measures?
A) Microorganisms used in recombinant DNA experiments are genetically crippled to ensure that they cannot survive outside of the laboratory.
B) Genetically modified organisms are not allowed to be part of our food supply.
C) Transgenic plants are engineered so that the plant genes cannot hybridize.
D) Experiments involving HIV or other potentially dangerous viruses have been banned.
2. In 1997, Dolly the sheep was cloned. Which of the following processes was used?
A) Use of mitochondrial DNA from adult female cells of another ewe
B) Replication and dedifferentiation of adult stem cells from sheep bone marrow
C) Separation of an early stage sheep blastula into separate cells, one of which was incubated in a surrogate ewe
D) Fusion of an adult cell's nucleus with an enucleated sheep egg, followed by incubation in a surrogate
3. Which of the following is FALSE about Air lift bioreactors?
a. Relies on an impeller system to mix the culture
b. Low shear rate, good mixing
c. High oxygenation capacity,
d. Efficient reactors for mass and heat transfer.
4. What is Hayflick’s Phenomenon?
- Cells will continue to grow and divide normally for a limited number of passages
- How much the growing cells cover the surface appear
- Exhibition of contact inhibition
- The unlimited life span of cells
4. Reproductive cloning of human embryos is generally considered unethical. However, on the subject of therapeutic cloning there is a wider divergence of opinion. Which of the following is a likely explanation?
A) Use of adult stem cells is likely to produce more cell types than use of embryonic stem cells.
B) Cloning to produce embryonic stem cells may lead to great medical benefits for many.
C) Cloning to produce stem cells relies on a different initial procedure than reproductive cloning.
D) A clone that lives until the blastocyst stage does not yet have human DNA.
5. Which of the followings is NOT true regarding the parameters necessary to control for adequate culture growth in animal cell bioreactors?
A. Heated water or air @ 37 C is commonly used to maintain temperature in Large fermenters.
B. Either by Co2 or alternative method is addition of acid or alkali to maintain Optimal pH - 7.4 – for maximum growth
C. Mammalian cell growth rates are considerably higher than those of most aerobic microorganisms and oxygen transfer requirements are therefore also proportionately higher.
D. In microbial cultures, oxygen transfer rates can be improved with smaller bubble size, higher stirring speeds and higher gas hold-up BUT Mammalian cells damaged (sheared) by turbulence and by the action of bursting bubbles.
6. Transfection refers to which of the following?
A. Synthesis of mRNA from DNA template
B. Synthesis of protein based on mRNA sequence
C. Introduction of foreign gene in to a cell
D. The process by which a cell become malignant
7. Production of transgenic animals require transfections of
A. Eggs or embryos B. Stem cells C. Red blood cells D. All of these
8. DNA is microinfected into the fertilized egg
A. After the fusion of male and female nuclei
B. Before the fusion of male and female nuclei
C. At the time of fusion of male and female nuclei
D. Any time, it can be infected
9. Which of the following is incorrect?
A. Established cell lines (ECL) have short doubling time
B. ECL is invariably aneuploid
C. ECL grow in higher density
D. ECL do not show much evidence of spatial orientation
10. Which of the following is FALSE about the effect of Shear forces/damage on animal cells in bioreactors?
a. Shear forces increase with the level of turbulence and on the type of agitator used.
b. The sensitivity of animal cells to liquid shear forces varies with the cell line and age.
c. Cells have been found to be more fragile during stationary and lag phases. Their robustness increases during exponential growth.
d. Using radial flow impellers is preferred on axial flow impellers
11. Tailoring Agitation for animal cell cultures include all of the following EXCEPT:
A. Maximum stirring rates for suspension – 100-150 rpm
B. Use of Microcarrier
C. Using flat bottomed vessels (animal cells) and Round bottom (bacterial cells)
D. Using axial flow impellers instead of radial flow impellers
12. Which of the followings is False about properties of embryonic stem cells?
- Unspecialized but capable of specialization and differentiation under certain stimulus and conditions
- Limited capacity of Self renewal
- Robust repopulation, the ability of cells to shift from a highly constrained to a vigorously active proliferative state
13. What is the approximate length of the RNA sequences that produce RNA interference?
a. 200-480 nucleotides b. 3 nucleotides c. 20-28 nucleotides d. 60-108 nucleotides
14. Why Eukaryotic cells are much more difficult to culture than most prokaryotes.
- They demand complex media
- They are very susceptible to damage, contamination and overgrowth by microbes such as bacteria, yeasts and fungi.
- grow more slowly than bacteria, so need less O2 rate and require gentler culture conditions and control systems required for lower metabolic rates
- all of the above
15. Which of the followings does NOT Influence Transfection Efficiency
a. Cell Health and Degree of Confluency b. Type of media
c. DNA Quality and quantity d. Contamination
16. Which of the following is FALSE about Lipofectamine?
- Positively charged lipids interact with negatively charged DNA. (Lipid-DNA complex). – Complex traverses cell membranes
- High transfection efficiency
- Does not induce immunological reactions
- Can be used on living tissue
17. RNAi methodology uses double-stranded pieces of RNA to trigger a breakdown or blocking of mRNA. For which of the following might it more possibly be useful?
A) to raise the rate of production of a needed digestive enzyme
B) to decrease the production from a harmful gain-of-function mutated gene
C) to destroy an unwanted allele in a homozygous individual
D) to form a knockout organism that will not pass the deleted sequence to its progeny
E) to raise the concentration of a desired protein
18. Which of the followings is false about Microcarriers?
- are small spherical beads (diam. 200 um).
- Used for anchorage-dependent cells can attach and grow
- Microcarrier decreases the SA available for cells to grow
- Increase density and so the product, and minimizes the cell damage due to agitation
19. Which of the following is true?
- Methotrexate is Antifolates cancer drug
- The enzyme dihydrofolate reductase is the primary site of action of most folate analogs such as methotrexate.
- Inhibition of this enzyme leads to toxicity through partial depletion of cofactors required for the synthesis of purines and thymidylate.
- Decreased drug uptake, amplification of the dihydrofolate reductase gene, mutations in the DHFR gene, and decreased ability to form methotrexate polyglutamate inside cells are the common mechanisms of drug resistance
- All of the above is true
20. Small RNAs may act as key regulators of ______________.
a. Viral infection b. Cancer c. Brain development
d. Apoptosis and fat metabolism e. All of the above