Multiple choice question for engineering
Set 1
1. Chlamyodomonas reinhardtii is a green, ______ algae.
a) unicellular
b) di-cellular
c) multicellular
d) either unicellular or di-cellular
Answer
Answer: a [Reason:] Chlamyodomonas reinhardtii is a green, unicellular algae. It has been used as a model system and studies have been carried out.
2. Chlamyodomonas genome is _______ rich.
a) AT
b) GC
c) Only A
d) Only C
Answer
Answer: b [Reason:] Chlamyodomonas genome is very GC rich. Hence, heterologous genes can’t be expressed until they come from a GC rich genome.
3. Integration of DNA into the Chlamydomonas genome is via homologous recombination. Is the given statement true or false?
a) True
b) False
Answer
Answer: b [Reason:] Integration of DNA into the Chlamydomonas genome is via non-homologous recombination. And because of this gene disruption can’t be carried out efficiently.
4. Transformation of Chlamydomonas is most efficient in which method?
a) Lithium acetate method
b) Electroporation
c) Protoplast based method
d) Both electroporation and protoplast based method
Answer
Answer: c [Reason:] Transformation of Chlamydomonas is most efficient in protoplast method. In this autolysin is used in order to carry out cell wall degradation.
5. OEE1 gene encodes a component of _________
a) photosystem I
b) photosystem II
c) both photosystem I and II
d) which neither belongs to photosystem I nor II
Answer
Answer: b [Reason:] OEE1 gene encodes a component which is a component of photosystem II. It allows mutant cells lacking that polypeptide to grow photoautotrophically.
6. Homologue of yeast ARG4 in Chlamydomonas is:
a) ARG1
b) ARG2
c) ARG5
d) ARG7
Answer
Answer: d [Reason:] ARG4 is present in yeast and is used for production of arginine and as a selectable marker. Homologue of yeast ARG4 in Chlamydomonas is ARG7.
7. cw15 is a mutant strain, it _____ and thus called as _____
a) lacks cell wall, natural protoplast
b) lacks cell wall, artificial protoplast
c) has cell wall, artificial protoplast
d) has cell wall, natural protoplast
Answer
Answer: a [Reason:] cw15 is a muatant strain. It lacks cell wall and thus it is called as natural protoplast. It is so because protoplasts are those structures which lack cell wall.
8. Genetic manipulation of Volvox carteri is carried out using nitrogen reducatse or antibiotic resistance. Is the given statement true or false?
a) True
b) False
Answer
Answer: a [Reason:] Genetic manipulation of green algae such as Volvox carteri is carried out by using nitrogen reductase or antibiotic resistance. They act as slectable markers.
9. For Chlorella, which method is used for DNA uptake?
a) Electroporation
b) Direct uptake of naked DNA
c) Conjugation
d) Chemically induced uptake by protoplast
Answer
Answer: d [Reason:] For Chlorella biolistic transformation is used. And apart from it, chemically induced uptake of DNA by protoplast is also used.
10. Members of genera Haematococcus are used for production of:
a) xanthenoid
b) carotenoid
c) chlorophyll
d) carotenoid and xanthenoid both
Answer
Answer: b [Reason:] Members of genera Haematococcus and Dunaliella are of economic importance and are used for production of carotenoids.
Set 2
1. Amplification of specific region can be done by using primers for specific regions. If the PCR product is ______ and is in sufficient quantity, then sequence can be determined ________
a) non-specific, directly
b) non-specific, indirectly or directly
c) specific, directly
d) specific, indirectly
Answer
Answer: c [Reason:] Amplification of specific region can be done by using primers for specific regions. If the PCR product is specific, it means that only a single band is obtained in gel electrophoresis and is in sufficient quantity then the sequence can be determined directly.
2. Which of the following is not suitable if the PCR product is non-specific?
a) Adjusting the concentration of magnesium ions
b) Increasing annealing temperature
c) Using touchdown PCR
d) Using inverse PCR
Answer
Answer: d [Reason:] In case, products are non-specific then sequence can’t be known directly. Optimization of PCR should be carried out and various other strategies should be used such as adjusting the concentration of magnesium ions, increasing annealing temperature or using touch-down PCR.
3. The disadvantage in the approach based on using PCR is that there is no permanent record until some of the bacterial cells are preserved. Is the given statement true or false?
a) True
b) False
Answer
Answer: a [Reason:] The disadvantage in this approach is that there is no permanent record until some of the bacterial cells are preserved. If enough bacteria are there initially then genomic library can be constructed.
4. How many approaches are there in order to clone the complete genome?
a) 1
b) 2
c) 3
d) 4
Answer
Answer: b [Reason:] There are basically two approaches in order to clone the complete genome. In the first approach systematic cloning is cloned is carried out. The second approach is based on cloning overlapping fragments at random.
5. If a full proteomic analysis of growth medium is carried out and is combined with ______ genome sequence, genes for other _____ proteins are also obtained.
a) partial, defensive
b) partial, secreted
c) complete, defensive
d) complete, secreted
Answer
Answer: d [Reason:] If full proteomic analysis of growth medium is carried out and is combined with complete genome sequence, genes for other secreted proteins can also be obtained.
6. If a putative protein sequence is cloned in an expression vector and the expressed protein is not showing protease activity, then which of the following is not correct?
a) The protein is not protease
b) The protein can be incorrectly folded which can block the protease activity
c) There might be some other cofactor required for protease activity
d) The most commonly used expression system is E.coli
Answer
Answer: a [Reason:] If the putative protein sequence is cloned and the expressed protein is not showing protease activity, it is not necessary that it is not protease. Suppression of protease activity can be because of incorrect folding or that some cofactor is required for protease activity. The most commonly used expression system is E.coli.
7. For getting large amount of proteins to crystallize, which of the following should be used as an expression system?
a) Bacterial system
b) Yeast systems
c) Eukaryotic systems
d) Both eukaryotic and bacterial systems can be used
Answer
Answer: d [Reason:] The system to be used for getting large amounts of proteins to crystallize can be either bacterial or eukaryotic. It depends on the source of the gene and whether post-translational modification is necessary or not.
8. If a mutation perturbs the structure, then stability and folding is not affected. Is the given statement true or false?
a) True
b) False
Answer
Answer: b [Reason:] At times mutated proteins are not expressed well. Mutation perturbs a structure at times and it affects the stability and folding of the protein.
9. The RNA level ______ the steady-state level of the corresponding protein directly and the post-translational modification of the protein ______.
a) reflects, can be determined
b) reflects, can’t be determined
c) doesn’t necessarily reflects, can be determined
d) doesn’t necessarily reflects, can’t be determined
Answer
Answer: d [Reason:] The RNA level doesn’t necessarily corresponds to the steady level of corresponding protein directly and the post-translational modification or location of the protein can’t be determined.
10. For a convenient transformation system, _____ can be used for gene silencing.
a) antisense RNA
b) transposon insertion
c) either antisense RNA or transposon insertion
d) transposon insertion followed by antisense RNA
Answer
Answer: a [Reason:] If a convenient transformation system is used, antisense RNA can be used for gene silencing. If the transformation system is not convenient then transposon insertion is used for silencing.
Set 3
1. Which of the following is useful in applications of PCR?
a) It is manual
b) Only one sample’s analysis can be carried out at a time
c) It is having a high speed
d) The amount of DNA required initially is high
Answer
Answer: c [Reason:] PCR is having numerous advantages over normal cloning procedures. It is automated and many samples can be analysed at a time simultaneously. It is having a high speed and the initial amount of DNA required is very less.
2. What is the correct statement with respect to ddNTPs?
a) They are dideoxynucleotide triphosphates
b) They are used in termination of DNA sequencing
c) They are used for initiating DNA sequencing
d) They are used in the case if the starting amounts are large
Answer
Answer: b [Reason:] ddNTPs are dideoxynucleoside triphosphates. It is used in the case for termination of sequencing. It is so because, both the hydroxyl molecules are removed sequencing would be terminated. It is beneficial in the case if the initial amounts are less.
3. Cycle sequencing is the DNA sequencing where very less amounts of template is utilised for carrying out the sequencing. The given statement is true or false?
a) True
b) False
Answer
Answer: a [Reason:] Cycle sequencing is that when very less amounts of DNA template is used for carrying out the sequencing. And the whole process is facilitated by the use of ddNTPs.
4. Sickle cell anaemia is a genetic disorder. Which of the following doesn’t holds true for it?
a) It can be analysed by PCR
b) It destroys a restriction site
c) The mutation is in alpha globulin gene
d) The conventional approach took weeks for the whole analyses to be carried out
Answer
Answer: c [Reason:] Sickle cell anaemia is a mutation in the beta globulin gene. It destroys a restriction site and the analyses can be carried out by PCR. PCR is very fast in comparison to conventional methods which took weeks to be completed. And the former method is completed in just one day.
5. PCR products can be analysed in many ways. Which of the following is not possible?
a) Use of restriction enzymes
b) Determining whether a particular oliginucleotide probe hybridizes to a PCR product
c) Electrophoresis
d) Direct sequencing can’t be carried out
Answer
Answer: d [Reason:] Restriction enzymes can be used and analyses can be done via destroying the restriction site. Checking for the hybridization of oligonucleotide probe with a PCR product. Electrophoresis can be used to check the mobility and compare it with a wild type molecule. Direct sequencing can also be carried out in order to analyse the PCR product.
6. Which of the statements don’t hold true for the forensics and the amplification carried out?
a) In the case of forensics, conventional methods such as southern blotting are used very effectively
b) In cases of bone fragments which contain less than 300 nucleotides conventional methods can’t be applied as they involve southern blotting, restriction digestion etc.
c) The poor condition of DNA also makes the PCR amplification difficult
d) Microsatellites composed of simply varying repeats of CA sequences is used
Answer
Answer: a [Reason:] In the case of forensics conventional methods are not very useful. If the bone fragments are having less than 300 nucleotides then the conventional methods can’t be applied easily.
7. The genetic relatedness between organisms can be identified by studying the band patterns when different PCR products are analysed electrophoreically. This method is called as:
a) restriction fragment length polymorphism (RFLP)
b) amplified fragment length polymorphism (AFLP)
c) random amplification of polymorphic DNA (RAPD)
d) polymorphism
Answer
Answer: c [Reason:] The genetic relatedness between organisms can be identified by studying the band patterns of different PCR products. This process is termed as random amplification of polymorphic DNA (RAPD).
8. PCR is useful in population genetics because at times it can be used to study genetics of bacteria that can’t be cultured axenically. Is the statement true or false?
a) True
b) False
Answer
Answer: a [Reason:] If properly designed primers are used then it is possible to amplify DNA from one organism that can’t be separated from others. For say a bacterial strain in a mixed population.
9. PCR amplification can be used for which type of samples?
a) Old samples only
b) Recent samples only
c) Equally to both recent and old samples
d) Recent samples are preferred but can be applied to old samples also
Answer
Answer: c [Reason:] PCR amplification can be used equally to both recent and old samples. DNA from museum samples and archaeological sites is also used for amplification.
10. What is problem associated with historical DNA samples?
a) They are less in amount thus amplification is difficult
b) Because the samples are very old, there can be contamination
c) They degrade during repeated cooling and heating cycles
d) As the samples are old, the standard sequences for comparison is not present
Answer
Answer: b [Reason:] The historical DNA samples though can be analysed but the main problem with them is that the duration for which they can be used. As the samples are very old they are often contaminated by bacteria.
Set 4
1. F (fertility) factor is used in many bacterial systems for different purposes. Choose the incorrect statement with respect to F factor.
a) It was identified in E. coli for catalysing genetic exchange between cells
b) Cells having F factor are called as female
c) The F factor is transferred from one cell to another via factors present outside
d) They are not related to BAC systems
Answer
Answer: a [Reason:] BAC vectors are based on the F (fertility) factor. They are known for transferring genetic material between cells and they do it by a proteinaceous filament called as sex pilus. The cells having F factor are called as male cells.
2. F factor integration into the host chromosome is called as:
a) F’ plasmid
b) F factor and host chromosome recombination
c) Hfr (High frequency of recombination)
d) Recombinant host chromosome
Answer
Answer: c [Reason:] F factor integration can be done into the host chromosome and this is called as Hfr (High frequency of recombination) strain.
3. Excision of F factor can also be done from the host chromosome. Choose the incorrect statement in respect to it.
a) This excision is possible in vivo
b) Along with F factor, host chromosome’s DNA sequences are also excised
c) The sequences of host chromosome which can be accommodated in the F plasmid are small in size
d) These plasmids are termed as F’ plasmids
Answer
Answer: c [Reason:] It is possible to carry out the excision of the F factor from the host chromosome. The excision is possible in vivo. Along with F factor, the DNA sequences of host chromosome are also excised. The F plasmid is able to accommodate very large size f host chromosome fragments and these are known as F’ plasmids.
4. The low copy number of F plasmid is essential for the stability of these plasmids. The given statement is true or false.
a) True
b) False
Answer
Answer: a [Reason:] Usually, the F plasmids are present in a low copy number in cells. These low copy numbers are very essential for the stability because then only few molecules can act as substrates for recombination mediated deletion.
5. Choose the correct statement for BAC vector system.
a) BAC vector system stands for bacteria and chromosome
b) It usually accepts insert of size approximately 1000kbp
c) The repE and oriS sequences are required for controlling the copy number and par A-C sequences are required for replication
d) A selectable marker is there for chloramphenicol resistance
Answer
Answer: d [Reason:] BAC vector system stands for Bacterial Artificial Chromosome. It accepts an insert of size 100kbp-300kbp. The repE and oriS sequences are required for controlling the replication and the par A-C sequences are required for controlling the copy number. A selectable marker is there for chloramphenicol resistance. A lacZ gene is also present and recombination of BAC vectors is done into E. coli by electropoartion.
6. The bacteriophage M13 vectors belong to a group of phages called as:
a) skinny or filamentous phage
b) M phage group
c) single stranded phage
d) double stranded phage
Answer
Answer: a [Reason:] Bacteriophage M13 vectors belong to a group of vectors known as skinny or filamentous phage. They have a dimension of 850 nm * 6 nm * 6nm. They are very useful as they convert the double stranded DNA into single stranded DNA.
7. Choose the correct statement for the infection process of M13.
a) The infectious particle is double stranded
b) It is contained in a protein coat which is made up of products of gene III or gene VIII
c) The phage infects only female cells
d) The phage enters the bacterial cells by the filament which is meant for movement
Answer
Answer: b [Reason:] M13 infectious particles are single stranded in nature. It is contained in a protein coat which is made up of products of gene III or gene VIII. The phage infects the bacterial cells by sex pilus and thus it infects only male cells.
8. Once the bacteriophage enters the bacterial cells, some changes are carried out in it. Which of the following is not included?
a) The single stranded molecule entering the cell is single stranded and is called as + strand
b) The single stranded molecule is converted into double stranded molecule which is called as replicative form (RF)
c) It is carried out in a process similar to normal replication process of E. coli
d) The positive strand is used for transcription of viral proteins
Answer
Answer: d [Reason:] Once the bacteriophage enters the bacterial cells it is converted into double stranded form from the single stranded form. The double stranded form is known as replicative form (RF). The single strand enteri g is called as + strand. It is carried out in a process similar to that the normal replication process. A specific origin of synthesis is used for transcription of the complementary negative strand. The minus strand can be used to synthesize viral proteins.
9. Replication can also be carried out by rolling circle replication. Choose the correct statement for this type of replication?
a) It can be used for the formation of RF
b) The product of gene III binds on a specific site of double stranded genome
c) It creates a nick in the – strand generating a free 3’ hydroxyl
d) This strand is extended by the polymerase and displaces the original – strand
Answer
Answer: a [Reason:] Rolling circle replication is used for the formation of RF. The product of gene II binds on a specific site of double stranded genome. It creates a nick in the + strand generating a free 3’ hydroxyl. This strand is extended by the polymerase and it displaces the original + strand. This strand is removed from the newly synthesized strand because of another nick by gene II. Thus a separate + strand is created and it is circularized by gene II product.
10. Gene V blocks the production of which gene?
a) Gene III
b) Gene II
c) Gene VIII
d) Gene IV
Answer
Answer: b [Reason:] Gene V blocks the production of gene II. As the gene V blocks the production of gene II, conversion of single strands into double strands is also blocked.
Set 5
1. An organism containing a gene which doesn’t belongs to it and is derived from somewhere else then the organism is said to be:
a) transformed
b) transgenic
c) mutant
d) modified
Answer
Answer: b [Reason:] An organism which contains a gene which doesn’t belongs to it and is derived from somewhere else, it is said to be transgenic.
2. E.coli is a gram negative bacterium. Is the given statement true or false?
a) True
b) False
Answer
Answer: a [Reason:] There are basically two types of bacteria, gram negative and gram positive. E.coli is a gram negative bacterium. These two groups are having properties which make them different.
3. If a host other than E.coli is to be used, what property of DNA to be inserted is disadvantageous?
a) Circular DNA
b) Linear DNA
c) Replicating DNA
d) Non-replicating DNA
Answer
Answer: c [Reason:] If the DNA is to be inserted in a host other than E.coli than the DNA can be circular or linear and it should be non-replicating. As it is non-replicating, it can be stably maintained in the host only by integration into replicon.
4. If plasmids direct their own transfer from one bacterium cell to another, then they are called as:
a) self-transmissible
b) auto-transmissible
c) autonomously replicating
d) auto-transfer
Answer
Answer: a [Reason:] It is important to transfer the plasmids from one bacterium to another. If, plasmids are able to direct their own transfer, then it is called as self-transmissible. There are some plasmids which do it with the help of other plasmids.
5. If a plasmid can’t be transferred from one cell to another, then it is called as:
a) non-transmissible
b) non-mobilizable
c) untransferrable
d) immobilized
Answer
Answer: b [Reason:] Some plasmids can’t be transferred from one cell to another even with the help of other plasmids. Such plasmids are said to be non-mobilizable.
6. Choose the incorrect statement for shuttle vectors.
a) These are vector hybrids constructed from E.coli and other plasmids
b) They are having a varied use
c) They can replicate and selected in both the species
d) They are the plasmids which are having naturally broad host range
Answer
Answer: d [Reason:] Shuttle vectors are those vector hybrids which are constructed artificially with the help of E.coli and other plasmids. They are able to replicate and selected in both the species and thus they are having a varied use. These are the plasmids which are having artificially broad host range because of introduction of an extra origin of replication.
7. Which of the bacteria are used as hosts?
a) Gram-positive
b) Gram-negative
c) Both gram positive and negative are preferred equally
d) Both can be used but gram positive is preferred
Answer
Answer: d [Reason:] Gram positive bacteria are particularly used as hosts. It is so because they secrete the expressed proteins in the growth medium at a much higher rate.
8. Basically, there are how many methods for introduction of DNA into the bacterial cells?
a) 1
b) 2
c) 3
d) 4
Answer
Answer: c [Reason:] There are basically three methods for introduction of DNA into the bacterial cells. These are the introduction of naked DNA, transformation of protoplasts and conjugation.
9. Gram-positive Bacillus, Streptococcus and Streptomyces include species that don’t exhibit natural competence. Is the given statement true or false?
a) True
b) False
Answer
Answer: b [Reason:] These include species which exhibit natural competence. It means that they take up DNA without any physiological treatment.
10. Competence is determined by the excretion into growth medium of _______, _________ proteins called as competence proteins.
a) cellular, high molecular weight
b) cellular, low molecular weight
c) extracellular, low molecular weight
d) extracellular, high molecular weight
Answer
Answer: c [Reason:] Competence proteins are the proteins which are extracellular and low molecular weight and they help in determination of competence. Competence further develops as cell density.
11. Natural transformation can be relieved by the use of protoplasts, in the presence of osmotic buffer and polyethylene glycol. What are protoplasts?
a) Protoplasts are the cells from which cell membrane has been removed
b) Protoplasts are the cells from which cell wall has been removed
c) Protoplasts are the cells from which vacuole has been removed
d) Protoplasts are the cells from which golgi bodies are removed
Answer
Answer: b [Reason:] Protoplasts are the cells from which cell wall has been removed. They help in relieving natural transformation in the presence of osmotic buffer and polyethylene glycol.
12. Transfer of plasmids from one cell to another can also be done conjugation. The plasmid to be transferred known as ______ is often unable to do so by itself and thus it relies on other plasmids known as ______
a) cargo, conjugal
b) conjugal, cargo
c) cargo, helper
d) conjugal, helper
Answer
Answer: a [Reason:] Plasmids can also be transferred from one cell to another through conjugation. Plasmids which are unable to transfer themselves are referred as cargo plasmids and they often rely on other plasmids which are called as conjugal plasmids. At times, helper plasmids are used in order to protect cargo plasmids from degradation.
13. The transfer of plasmid from one bacterial cell to another when cargo and conjugal plasmids are used, it is usually is carried out by _____ mating.
a) diparental
b) uniparental
c) triparental
d) multiparental
Answer
Answer: c [Reason:] The transfer is carried out by triparental mating. Three conjugants are used, E.coli carrying the conjugal plasmid, E.coli containing cargo and helper plasmid and the recipient bacterial species to be manipulated.