MCQOPTIONS
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MCQOPTIONS
This section includes 53 Mcqs, each offering curated multiple-choice questions to sharpen your Genetic Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
What is the disadvantage of amplification of using PCR over natural cloning? |
| A. | In PCR, there is no proof reading activity |
| B. | In PCR, small fragments can’t be amplified |
| C. | There is an A incorporated in PCR products, which makes cloning difficult |
| D. | PCR takes more time as compared to natural cloning |
| Answer» B. In PCR, small fragments can’t be amplified | |
| 2. |
What happens if insert DNA is cut with two different restriction enzymes at the ends? |
| A. | It is difficult to insert the fragment |
| B. | The insert can be ligated in any orientation |
| C. | The insert can be ligated in one orientation only |
| D. | The amount of product increases |
| Answer» D. The amount of product increases | |
| 3. |
ccdB gene is used at times. Choose the correct statement with respect to this gene. |
| A. | It is a control of cell birth gene |
| B. | It is activated in complex vectors to increase the fraction of recombinants |
| C. | If intramolecular ligation takes place this protein is released |
| D. | It is often regarded as control of cell death and birth gene |
| Answer» C. If intramolecular ligation takes place this protein is released | |
| 4. |
TA cloning is a method used for cloning of PCR products. Which of the statement is correct with respect to it? |
| A. | It is based on the fact that a T residue is incorporated at the end of the PCR product |
| B. | ‘A’ residue is incorporated into the end of the vector |
| C. | It gives a low yield |
| D. | It is preferred over blunt end ligation |
| Answer» E. | |
| 5. |
When inserting a DNA fragment, it is possible to have two orientations. If the orientation is controlled, this cloning is referred to as __________ |
| A. | forced cloning |
| B. | orientation cloning |
| C. | correct cloning |
| D. | restricted cloning |
| Answer» B. orientation cloning | |
| 6. |
Methylation dependent restriction system (MDRS) are included in which class of restriction enzymes? |
| A. | Type I |
| B. | Type II |
| C. | Type III |
| D. | They are the product of mcrA, mcrB or mrr loci |
| Answer» E. | |
| 7. |
How many recombination systems are present in E. coli? |
| A. | 1 |
| B. | 2 |
| C. | 3 |
| D. | 4 |
| Answer» D. 4 | |
| 8. |
Endogenous DNA-degrading system is not essential in determining transformation efficiency. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | Can't say |
| Answer» C. May be True or False | |
| 9. |
The cell in which the recombinant molecules are propagated is termed as __________ |
| A. | host |
| B. | vector |
| C. | plasmid |
| D. | carrier |
| Answer» B. vector | |
| 10. |
Which of the following is true for K strain for E. coli? |
| A. | It contains restriction-modification system which is encoded by hsDMRS locus |
| B. | hsDR encodes for endonuclease which is responsible for cleaving the DNA sequence containing –AACGCNNTGC- |
| C. | Cleavage is carried out when the second A is non methylated |
| D. | hsDR mutation can be used for cleavage of incoming unprotected DNA |
| Answer» B. hsDR encodes for endonuclease which is responsible for cleaving the DNA sequence containing –AACGCNNTGC- | |
| 11. |
Some mutations are present which assist the uptake of DNA. Which of the statement is incorrect for it? |
| A. | deoR is such a mutation which assists the uptake of DNA |
| B. | It is a transcriptional regulator |
| C. | It is having DNA binding activity |
| D. | It controls the expression of a set of genes involved ribonucleoside catabolism |
| Answer» E. | |
| 12. |
Choose the incorrect statement in respect to topoisomerase I. |
| A. | It is used to cleave only one DNA strand |
| B. | It leaves at the recognition sequence –C/TCCTT- and is covalently attached to one end of the cleaved molecule |
| C. | The supercoiling of the DNA strand is altered and then it is sealed again by the enzyme |
| D. | It is slower than the normal DNA ligase |
| Answer» E. | |
| 13. |
There is no effect if the insert itself contains the restriction site. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | Can't say |
| Answer» C. May be True or False | |
| 14. |
Linkers are often used in cloning. Choose the incorrect statement for linkers. |
| A. | These are short chemically synthesized molecules that contain a particular restriction enzyme site within the sequence |
| B. | They are blunt ended molecules |
| C. | They are ligated to staggered ended insert molecules by T4 DNA ligase |
| D. | After treatment with enzyme, both the ends of the linker are staggered |
| Answer» D. After treatment with enzyme, both the ends of the linker are staggered | |
| 15. |
endA mutation is often induced in host molecules. Choose the correct statement. |
| A. | It activates the gene for DNA-specific endonuclease |
| B. | It enhances the yield of plasmid DNA preparations only |
| C. | It enhances the quality of plasmid DNA preparations only |
| D. | It enhances both the quality and yield of plasmid DNA preparations |
| Answer» E. | |
| 16. |
lacZΔM15 represents __________ |
| A. | fully present lacZ gene |
| B. | it is not required in alpha complementation |
| C. | it represents the lacZ gene with M15 mutation |
| D. | it is partially deleted lacZ gene which is needed for alpha complementation |
| Answer» E. | |
| 17. |
Disablement is also done in plasmids. Choose the correct statement. |
| A. | The strains carrying out the recombinant plasmids should not escape outside |
| B. | Preferred strains are having mutations which allow their growth in wild |
| C. | Mutations confer prototrophy |
| D. | If the recombinants escape outside, there is no such harm |
| Answer» B. Preferred strains are having mutations which allow their growth in wild | |
| 18. |
Choose the incorrect statement with respect to dam and dcm genes? |
| A. | Their enzymes are responsible for methylation of DNA |
| B. | Dam protein methylates cytosine in –GATC- |
| C. | Dcm methylates cytosine in-CCAGG- and –CCTGG- sequences |
| D. | The extent of methylation also has effects on the efficiency with which the other restriction enzymes cleave the DNA in vitro |
| Answer» C. Dcm methylates cytosine in-CCAGG- and –CCTGG- sequences | |
| 19. |
Size of the vector is related to having a suitable single restriction site. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | Can't say |
| Answer» B. False | |
| 20. |
If a restriction site is 6 nucleotides long, what are the chances of finding it in a vector? |
| A. | Once every 46 base pairs |
| B. | Once every 64 base pairs |
| C. | Once every 24 base pairs |
| D. | Once every 16 base pairs |
| Answer» B. Once every 64 base pairs | |
| 21. |
Multiple cloning site (MCS) is defined as __________ |
| A. | site within the plasmid which contains a site for many restriction enzymes |
| B. | site within the plasmid which contains a site for many restriction enzymes and they are not present anywhere else in the plasmid |
| C. | as the site containing many sites for only one restriction enzyme |
| D. | cloning many inserts together |
| Answer» C. as the site containing many sites for only one restriction enzyme | |
| 22. |
It is required to distinguish between the cells that have taken up the vector and that have not. It is done by using __________ |
| A. | multiple cloning site |
| B. | origin of replication |
| C. | high copy number |
| D. | selectable marker |
| Answer» E. | |
| 23. |
Which of the statement is true for pBR322? |
| A. | It contains only an ampicillin resistance gene |
| B. | It contains both ampicillin resistant and tetracycline resistant gene |
| C. | The cloning site is present only in the ampicillin resistant gene |
| D. | It is a natural vector |
| Answer» C. The cloning site is present only in the ampicillin resistant gene | |
| 24. |
Alkaline Phosphatase is used at times and the vector is treated with it. Choose the incorrect statement. |
| A. | It removes 5’ terminal phosphate group from nucleic acids |
| B. | The 5’ phosphate group is required for the ligation to take place |
| C. | Two phosphate bonds should be formed for the complete ligation to take place |
| D. | The ligation between vector and insert won’t take place |
| Answer» E. | |
| 25. |
At times it is observed that non-recombinant plasmids are more than that of recombinant plasmids. Choose the correct statement in regard to it. |
| A. | It makes easier to get the recombinant plasmids from the mixture |
| B. | The ratio of insert DNA to vector DNA is reduced to get recombinant plasmids |
| C. | Alkaline phosphatase is used to get recombinant plasmids |
| D. | Alkaline phosphatase method is less reliable in comparison to the ratio method |
| Answer» D. Alkaline phosphatase method is less reliable in comparison to the ratio method | |
| 26. |
What is the correct time for carrying out the alkaline phosphatase treatment? |
| A. | After the cutting of vector has been done |
| B. | Before the insert DNA and the vector are mixed |
| C. | After the cutting of vector has been done but before the insert DNA and vector are mixed |
| D. | After the mixing of insert DNA and vector |
| Answer» D. After the mixing of insert DNA and vector | |
| 27. |
The correct statement with respect to lacIq is __________ |
| A. | It is a mutant of lac repressor gene and decreases the level of repressor |
| B. | It doesn’t control the lacZ gene |
| C. | It is important for the vectors to replicate in a low copy number |
| D. | It doesn’t titrate out the repressor produced by wild type Lac-I gene |
| Answer» B. It doesn’t control the lacZ gene | |
| 28. |
The phenomenon of not allowing the recombinants to escape into the environment is termed as __________ |
| A. | blocking |
| B. | termination |
| C. | disablement |
| D. | inactivation |
| Answer» D. inactivation | |
| 29. |
There are various methods to distinguish whether a colony contains a recombinant or not. One such method is __________ |
| A. | blue white screening |
| B. | checking whether replication is taking place or not |
| C. | checking the number of copies |
| D. | looking for the multiple cloning site |
| Answer» B. checking whether replication is taking place or not | |
| 30. |
How will we choose which transformation method is to be used? |
| A. | It depends on the available conditions for the reaction to take place |
| B. | It depends on the efficiency which is required to be obtained |
| C. | All the transformation methods can be used equivalently |
| D. | Each reaction has been assigned a particular transformation method |
| Answer» C. All the transformation methods can be used equivalently | |
| 31. |
If high copy number is there, the replication is called as ______ and if low copy number is there the replication is called as ______ |
| A. | stringent, relaxed |
| B. | relaxed, stringent |
| C. | relaxed, relaxed |
| D. | stringent, stringent |
| Answer» B. relaxed, stringent | |
| 32. |
Chloramphenicol amplification is carried out in various plasmids. Which of the statement is incorrect for it? |
| A. | It is used for increasing copy number in plasmids containing pMB1 origin |
| B. | Chloramphenicol promotes bacterial protein synthesis |
| C. | The protein synthesis is responsible for chromosomal DNA replication |
| D. | Chromosomal DNA replication is related to cell division |
| Answer» C. The protein synthesis is responsible for chromosomal DNA replication | |
| 33. |
If a plasmid is having two antibiotic resistant genes, say ampicillin resistant and chloramphenicol resistant. If the plasmid grows in ampicillin containing medium but not in chloramphenicol, what can be concluded? |
| A. | The insert is not present in any of the gene |
| B. | The insert is present in ampicillin gene but not in chloramphenicol gene |
| C. | The insert is present in choramphenicol gene but not in ampicillin gene |
| D. | The insert is present between both of the genes |
| Answer» D. The insert is present between both of the genes | |
| 34. |
If genomic DNA has been inserted instead of the plasmid, what will happen? |
| A. | It would lead to inactivation of lacZ gene |
| B. | The X-gal substrate would be broken down |
| C. | The colonies formed are blue in colour |
| D. | The lacZ gene would be intact |
| Answer» B. The X-gal substrate would be broken down | |
| 35. |
Insertion of DNA into lacZ gene may lead to disruption of the gene function. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | Can't say |
| Answer» B. False | |
| 36. |
Generation of recombinants by randomly cloning fragments of total DNA from an organism is called as __________ |
| A. | genomic library |
| B. | screening |
| C. | recombination |
| D. | shotgun cloning |
| Answer» E. | |
| 37. |
Which of the following is true regarding taking up of plasmid DNA in the bacterial cells? |
| A. | There are more chances of having two plasmids in a single cell |
| B. | There are more chances of having a single plasmid in one cell |
| C. | Uptake upto two plasmids is possible but not more than that |
| D. | Both are taken up with the same efficiency |
| Answer» C. Uptake upto two plasmids is possible but not more than that | |
| 38. |
Often PCR can be performed in order to confirm whether an insert is present in the plasmid. Cells are taken directly and PCR is performed, this type of PCR is known as __________ |
| A. | direct PCR |
| B. | colony PCR |
| C. | quantitative PCR |
| D. | in-situ PCR |
| Answer» C. quantitative PCR | |
| 39. |
What will be the consequence of not having an origin of replication (ori) in the vector? |
| A. | If an ori is absent, replication of vector would not take place |
| B. | As the cells divide after taking up the vector, both the daughter cells would be having the vector |
| C. | A colony of transformed colonies is observed |
| D. | The vector won’t be taken up by the cell |
| Answer» B. As the cells divide after taking up the vector, both the daughter cells would be having the vector | |
| 40. |
Why the whole lacZ gene can’t be present in the plasmid at one time? |
| A. | Because the whole lacZ gene can’t be present anywhere |
| B. | The whole lac Z gene is very large in size and the plasmid size is small |
| C. | The whole lacZ gene is never functional |
| D. | Because the plasmid takes is having a restriction site only for taking up a portion of the lacZ gene |
| Answer» C. The whole lacZ gene is never functional | |
| 41. |
The phenomenon of alpha complementation is __________ |
| A. | α + β = ω |
| B. | α = β + ω |
| C. | β = α + ω |
| D. | It is either α + β = ω or β = α + ω |
| Answer» B. α = β + ω | |
| 42. |
Alpha complementation is an indicator of lacZ system. Which of the statement is incorrect for it? |
| A. | One portion of the lacZ gene known as minigene is present in the plasmid |
| B. | Another portion is present in the host itself |
| C. | If they both are allowed to combine in the presence of IPTG, X-gal and ampicillin, blue colonies are observed |
| D. | If insert is also present along with host and plasmid, it results in the formation of blue colonies |
| Answer» E. | |
| 43. |
An operon is defined as __________ |
| A. | A related set of genes each having different promoters and are present differently |
| B. | A set of genes which are present together but are controlled by different promoters |
| C. | A set of genes which are present together and are controlled by the same promoter |
| D. | A set of genes which are not present together but controlled by the same promoter |
| Answer» D. A set of genes which are not present together but controlled by the same promoter | |
| 44. |
Which of the following orientation is not propagated to later stages? |
| A. | Circular plasmids having genomic DNA |
| B. | Intramolecular ligation of plasmids |
| C. | Linear molecules |
| D. | Head to head ligation of two DNA plasmids |
| Answer» D. Head to head ligation of two DNA plasmids | |
| 45. |
Bla is a gene, which is incorrect for it? |
| A. | It is an antibiotic resistance genes |
| B. | Antibiotic acts by blocking the cross-linking of the bacterial cell wall and thus leading to lysing of cells |
| C. | It encodes beta lactamase enzyme |
| D. | The beta lactam ring is activated |
| Answer» E. | |
| 46. |
Molecules having new combination of sequences that were not present before are called as __________ |
| A. | intermolecular ligants |
| B. | recombinants |
| C. | couple |
| D. | intramolecular ligants |
| Answer» C. couple | |
| 47. |
Which of the characteristics is present in lacZ gene? |
| A. | It encodes for beta galactosidase enzyme |
| B. | Beta galactosidase enzyme is responsible for cleaving monosaccharides into the constituent elements |
| C. | It doesn’t cleaves a substrate called as X-gal |
| D. | But if X-gal is cleaved, it liberates pink coloured dye |
| Answer» B. Beta galactosidase enzyme is responsible for cleaving monosaccharides into the constituent elements | |
| 48. |
Which of the following characteristic is not present in a plasmid on a general basis? |
| A. | Multiple cloning site (MCS) |
| B. | Origin of replication (ori) |
| C. | Antibiotic resistance gene |
| D. | Beta galactose genes |
| Answer» E. | |
| 49. |
Choose the correct statement for adaptors. |
| A. | They are blunt ended at both the ends |
| B. | They are single stranded at both the ends |
| C. | They may be single stranded at one end and other end may be blunt |
| D. | They don’t have extra restriction sites within their sequence |
| Answer» D. They don’t have extra restriction sites within their sequence | |
| 50. |
If linkers are combined with other features such as a selectable marker, it is called as __________ |
| A. | cassette |
| B. | modified linker |
| C. | adaptors |
| D. | induced linker |
| Answer» B. modified linker | |