20. Inbreeding for 5 generations led to production of homozygous transgenic mice. However, these homozygous males or females were infertile. Which of the following approach is most preferable and economical to obtain heterozygous transgenic animals continuously? (1) More transgenic founder (1st animal) should be generated. (2) Crossing (breeding) of transgenic mice with wild type mice in earlier generations should be done for continued production of transgenic heterozygous offspring. (3) Inbreeding should be avoided after 5th generation. (4) Homozygous transgenic mice should be mated with wild type mice for continued production of transgenic heterozygous offspring.

Maintaining a line of heterozygous transgenic mice

19. A student added DMEM culture medium which was pink in colour to growing liver cells. Three days later the medium colour was yellow. This indicated (1) change in cell morphology (2) change in pH of the medium (3) depletion of nutrients in the medium (4) lack of antibiotics in the culture

Why DMEM turns yellow in liver cell culture

18. Which is best method for checking mycoplasma contamination in a mammalian cell line? (1) Southern Hybridization (2) ELISA (3) PCR (4) Western Hybridization

Method to detect mycoplasma contamination in mammalian cell cultures

17. To prepare individual tissue cells from a primary culture, the cell-cell and cell-matrix interaction must be broken. To achieve this would NOT use: (1) EDTA (2) Trypsin (3) Collagenase (4) Separase

Reagents used to dissociate primary tissues into single cells

16. Which one of the following statements is NOT correct for propagation and maintenance of mammalian cells in vitro? (1) Transformed cell lines do need external supply of serum to grow. (2) The cells that are obtained directly from the organism is a primary culture. (3) Trypsin is added to cell culture media to maintain cell's health. (4) HEPES buffer is generally used to maintain pH of the culture media.

Key facts about maintaining mammalian cells in vitro

15. The following statements are made regarding developing a transgenic mouse: A. The transgenic mouse thus born will be a homozygous transgenic animal and can be maintained by crossing with another transgenic animal. B. The fertilized transgenic eggs are allowed to develop in vitro. C. The desired gene is preferably microinjected in male pronucleus after sperm entry in oocyte. D. For best efficiency, the desired gene is always microinjected in the male gametes and then they are allowed to fertilize the female gametes. E. Blastocyst stage embryos are transferred to the uterus of hormonally prepared mother. F. The fertilized eggs are collected from specific strain of mouse. G. The female mouse of specific strain is super ovulated, oocytes are collected and allowed to fertilize in vitro. Choose the combination of statements arranged in the correct sequence for developing transgenic mouse. (1) G→C→E (2) F→B→A (3) G→D→A (4) D→F→B→A

Procedure to develop a transgenic mouse by pronuclear microinjection

14. Animal cell cultures are frequently used for production of therapeutic proteins. NIH3T3 (a fibroblast cell line) and CHO (Chinese hamster ovarian cell line) are some of the popular cell lines used. Choose the best combination of cell line (for transfection) and starting material for purification of human growth hormone, a secretary protein (1) NIH3T3 cell pellet (2) CHO and cell pellet (3) NIH3T3 and culture medium (4) CHO and culture medium

Best system and starting material to purify secreted human growth hormone

13. Which one of the following techniques is generally used to produce transgenic animals? (1) Processed mRNA containing only exons are introduced into blastocyst stage embryo. (2) Entire foreign nucleus is introduced in enucleated unfertilized egg. (3) Desired DNA is micro injected into fertilized eggs followed by implantation of embryo in a foster mother. (4) c-DNA of desired gene is introduced into animal embryos and implanted in a foster mother

Standard method for producing transgenic animals

12. To keep them in a totipotent state, embryonic stem cells need to be maintained in a medium supplemented with (1) growth hormone (2) leukemia inhibiting factor (3) nestin (4) insulin

Factor required to maintain embryonic stem cells in a totipotent/pluripotent state

11. For developing transgenic mice, embryonic stem cells are engineered to express the transgene. These cells are selected by (1) novobiocin. (2) neomycin. (3) tetracycline. (4) penicillin.

Antibiotic selection of embryonic stem cells in transgenic mouse production

10. The genes whose promoters are extensively used for production of pharmaceutical proteins in transgenic dairy cattles are (1) lactalbumin and ovalbumin. (2) lactoglobulin and casein. (3) lactoferrin and transferrin. (4) casein and ovalbumin.

Promoters used to produce pharmaceutical proteins in transgenic dairy cattle

9. Which of the following host systems is best suited to express large amounts of glycosylated protein for structural studies? (1) GST fusion protein in E. coli (2) His-tagged protein in E. coli (3) Native protein in Baculovirus (4) Native protein in Pseudomonas fluorescens

Best expression system for large amounts of glycosylated protein

8. For sustainable expression of a trangene in the successive generation of a cell line in culture, the ideal gene transfer can be obtained using (1) lentiviral vector (2) adenoviral vector (3) plasmid DNA containing the transgene (4) only transgenic DNA

Best method for stable, heritable transgene expression in cultured cell lines

7. Application of gene therapy in clinical trials did NOT succeed due to (1) poor integration of a gene in the host genome (2) lack of expression of integrated gene in cells (3) degradation of gene inside the cell (4) activation of oncogenes consequent to integration of the gene

Why some early clinical gene therapy trials failed

6. Integrity of introduced transgene in mouse can be validated by (1) Male pronuclear insertion (2) Fusion of enucleated egg with somatic cells (3) Transfer into competent embryogenic cell (4) Southern blot analysis

How to validate integrity of an introduced transgene in mice

5. Which of the following system can be utilized for glycosylation of peptides expressed using recombinant DNA technology? (1) Large bacterial fermenters (2) Small bacterial fermenters (3) Normal bacterial bioreactors (4) Mammalian Cell line

Choosing the right expression system for glycosylated recombinant peptides

4. For making transgenic animals in fertilized egg the preferred place to insert trans-gene is in (1) Female pronuclei (2) Male pronuclei (3) Cytoplasm (4) Cleavage cells

Why the male pronucleus is used for transgene insertion in fertilized eggs

3. Which of the following methods can be used to selectively lyse newly dividing cells? (1) MTT (3-(4,5-Dimethylthiazol- 2-yl) – 2,5- diphenyltetrazolium bromide) treatment of dividing cells followed by UVB irradiation (2) Treatment of dividing cells with caspase inducers (3) Bromodeoxyuridine (BrdU) labelling of dividing cells followed by exposure to light (4) Treatment of dividing cells with 51Cr and measuring its release over a period of time.

Selective lysis of newly dividing cells using BrdU and light

2. If you want to selectively kill the newly dividing mammalian cells in a cell culture assay, which of the following methods will you use? (1) Exposure to UV radiation at 250 nm. (2) Treatment with 5-ethynyl-2'-deoxyuridine (EdU), followed by doxorubicin hydrochloride treatment. (3) Treatment with 5-bromo-2'- deoxyuridine (BrdU), followed by UV-A exposure (4) Tritiated thymidine treatment followed by vinblastine treatment

How to selectively kill newly dividing mammalian cells in culture

1. Leukemia inhibiting factor has been utilized in animal cell culture for (1) Stimulating growth of cell (2) Inhibiting differentiation of stem cells (3) Inducing morphogenesis (4) Arrest cells at mitosis

Role of Leukemia Inhibitory Factor (LIF) in animal cell culture

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