Multiple choice question for engineering
1. There are various methods to distinguish whether a colony contains a recombinant or not. One of 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
2. 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
3. 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
4. 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
5. ccdB gene is used at times. Choose the correct statement in 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
6. 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
7. 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
8. 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
9. 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 low yield
d) It is preferred over blunt end ligation
10. Choose the incorrect statement in respect to topoisomerase I.
a) It is used to cleave only one DNA strand
b) It cleaves 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
11. 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
12. There is no effect if the insert itself contains the restriction site. The given statement is true or false?
13. 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
14. If linkers are combined with other features such as a selectable marker, it is called as:
b) modified linker
d) induced linker
1. What are the possibilities which can occur until the temperature has reached for primer annealing?
a) Extension doesn’t starts until the appropriate temperature is reached
b) Extension may start even when the temperature is low
c) At low temperature, there is specific annealing of primer taking place
d) There are more specific products which are generated
2. Hot-start PCR is a modification of PCR. Which of the following is not corresponding to it?
a) The basis is that extension is not started until the first cycle reaches its maximum temperature
b) The polymerase is added after the first cycle has reached its maximum temperature or melting temperature
c) It is satisfactory for small number of samples
d) It leads to generation of non specific products
3. An alternative to adding polymerase at later stage is:
a) Make the polymerase inactive by binding it to an antibody
b) Introduce the polymerase or Magnesium in clay beads
c) Make the polymerase inactive by attaching groups which cause stearic inhindrance
d) Introduction of polymerase or Magnesium in plastic wires
4. The primer annealing temperature is often very low from the maximum temperature. This low temperature leads to some mismatches. Is the statement true or false?
5. Touch-down PCR is another modification. Its characteristics include:
a) Lowering the temperature for primer annealing
b) Primer annealing is done at higher temperatures initially
c) The temperature is abruptly reduced in the second cycle
d) In earlier cycles less stringent conditions are there and in later cycles more stringent conditions are there
6. If two successive PCR are carried out, it is called as:
a) Touch-down PCR
b) Hot-start PCR
c) Combined PCR
d) Nested PCR
7. If two successive PCRs are carried out, in which PCR there are chances of having a non-specific product?
a) First PCR
b) Second PCR
c) Both the PCRs
d) It depends on the annealing temperature
8. The process of inserting an amplified PCR product in a vector for cloning is known as:
a) making library
c) making a hard copy
d) making a PCR based vector
9. How can PCR product be cloned into a vector?
a) It can be done only when PCR products are blunt-ended
b) It can be done only by restriction enzyme digestion
c) Both the methods can be used
d) The blunt-ended approach is favoured
10. Which of the following statement is incorrect regarding cloning of PCR products?
a) In cloning via restriction enzymes, restriction sites are induced before amplification is carried out
b) The restriction sites are induced in the primers before annealing
c) The intermediate molecules are having restriction sites at both ends
d) The amplified molecules can be cut at both the ends by appropriate enzymes
11. Topoisomerse I is also used for cloning of PCR product at times. Which of the statement holds true for such type of cloning?
a) The restriction site is induced into the vector and the topisomerase enzyme is induced into the PCR primers
b) The topoismerase I is used for cutting both the strands
c) The induction of topoisomerase enzyme is done into the vector in the case it is very small in size
d) The restriction site is induced into the PCR primers and the topoisomerase enzyme is induced into the vector
12. Generally, amplification is carried out between the PCR primers. But if amplification is carried out outside the primers, it is called as:
a) Inverse PCR
b) Circular PCR
c) Non-conventional PCR
d) In-situ PCR
1. Mitochondrial genome encodes tRNAs, _____ and polypeptides involved in _______
a) mRNAs, oxidative phosphorylation
b) rRNAs, oxidative phosphorylation
c) rRNAs, reductive phosphorylation
d) mRNAs, reductive phosphorylation
2. Atrazine is a herbicide and it acts on:
a) reaction centre in photosystemI
b) reaction centre in photosytemII
c) reaction centre in both the photosystems
d) neither of the photosystems
3. Allotopic gene expression is the case when the presence of a normal gene in an organelle is not a problem in expression. Is the given statement true or false?
4. atpB encodes _______ subunit of ATPsynthase, an enzyme used for generation of ______
a) beta, ADP
b) alpha, ATP
c) beta, ATP
d) alpha, ADP
5. Bacterial aadA gene is responsible for conferring resistance to:
d) spectomycin and streptomycin
6. How many types of chloroplast are there in Chlamydomonas?
7. For transformation of chloroplast of higher plants, a vector is used which ______ in the chloroplast.
a) doesn’t replicates
c) may or may not replicate
d) replicates under certain specified conditions
8. Chloroplast can be transferred through pollen in all crops. Is the given statement true or false?
9. Mutant strains of Saccharomyces cervevisiae in which endogenous DNA are deleted are called as:
b) synthetic rho
10. COX3 gene is a selectable marker. Choose the correct statement with respect to it.
a) It confers the ability to grow by anaerobic respiration
b) It confers the ability to grow by aerobic respiration
c) It confers the ability to grow in absence of uracil
d) It confers the ability to grow in lithium acetate medium
11. The ARG8m gene which produces an enzyme for arginine biosynthesis is located in _______ and is of ______ origin.
a) mitochondrial, nuclear
b) nuclear, mitochondrial
c) nuclear, nuclear
d) mitochondrial, mitochondrial
12. Barstar is:
b) RNAse inhibitor
d) DNAse inhibitor
13. Caenorhabditis elegans is a model organism of great importance in biological systems. It is a/an:
14. DNA can be injected into Caenorhabditis elegans by biolistic transformation. The injected DNA forms arrays of extrochromosomal copies which are stable in nature. Is the given statement true or false?
1. Basic classification of polymerases includes how many types?
2. Polymerase can be defined as:
a) an enzyme used to synthesize a new DNA or RNA strand on the basis of pre-existing strand or at times without a pre-existing strand
b) an enzyme used for removal of nucleotides from the DNA or RNA strand
c) an enzyme which can synthesize only a new DNA strand, not a RNA strand
d) an enzyme which can synthesize either a new DNA or a RNA strand but only when a strand is there
3. Which of the following activity is not possible in the case of DNA polymerase I?
a) 3’-5’ exonuclease
b) 5’-3’ exonuclease
c) 5’-3’ DNA synthesis
d) 3’-5’ DNA synthesis
4. The E. coli DNA polymerase enzyme gives different domains with different activities on cleaving with protease subtilisin. Which of the following statements is correct with respect to the fragments generated?
a) The smaller fragment is having C terminal and the larger fragment is having N terminal
b) The smaller fragment is named as Klenlow fragment and the intact molecule is called as Kornberg fragment
c) The smaller fragment is having 5’-3’ exonuclease activity whereas the larger fragment is having 5’-3’ polymerase and 3’-5’ exonuclease activity
d) Both the fragments are having 5’-3’ polymerase and 3’-5’ exonuclease activity
5. Removal of single stranded portions produced due to exonucleolytic activity and due to polymerase activity are termed as:
a) polishing and end filling respectively
b) end filling and polishing respectively
c) polishing in both the cases
d) end filling in both the cases
6. Thermostable DNA polymerases are very important in PCR. How are they obtained?
a) They are obtained by heating the bacteria manually over high temperatures
b) They are isolated from extremely stable thermophilic bacteria which are often found growing in oceanic vents
c) They are found everywhere in the nature
d) They are obtained by genetically modifying the E. coli bacteria with thermal stability property
7. Which of the following enzyme is said as reverse transciptase?
a) DNA dependent DNA polymerase
b) RNA dependent RNA polymerase
c) RNA dependent DNA polymerase
d) DNA dependent RNA polymerase
8. Why reverse transciptase enzymes are having comparatively high error rates than other polymerases?
a) Because they are not having 3’-5’ proofreading exonucleolytic activity
b) Because they are not having 5’-3’ proofreading exonucleolytic activity
c) Because they are having slow rates of exonucleolytic activity
d) It is difficult to synthesize DNA from RNA
9. Which polymerase can be used in conjunction with appropriate phage promoters in order to have high levels of specific transcription?
a) RNA dependent DNA polymerase
b) DNA dependent RNA polymerase
c) RNA dependent RNA polymerase
d) DNA dependent DNA polymerase
10. Template independent polymerases are the enzymes which add nucleotide bases without a template. Which of the following statements is correct with respect to these?
a) They only add a single nucleotide
b) They only add a string of nucleotides and not a single nucleotide
c) Terminal transferase adds a series of nucleotides at the 3’ end
d) Taq polymerase adds a single nucleotide at the 5’ end of the PCR product
1. If methods are based on cellular processes that lead to inactivation of gene expression by affecting the RNA, then it is called as:
2. Choose the incorrect statement for the method based on antisense RNA.
a) RNA is synthesized complementary to the sequence of the gene which is to be inactivated
b) It is achieved by placing a DNA sequence which encodes RNA complementary to the RNA to be inactivated
c) Expression of the endogenous gene is diminished
d) This method is preferred over gene disruption has gene inactivation can be achieved completely
3. The method of post transcriptional gene silencing is particularly useful in:
4. Down regulation of expression of endogenous genes by transformation with constructs that would generate sense RNA, rather than anti-sense RNA is known as:
5. In some organisms, presence of double stranded RNAs leads to breakdown of corresponding single stranded mRNA. Is the given statement true or false?
6. Double stranded RNA is cleaved by a nuclease called as Dicer and small fragments are generated known as:
a) short interfering RNAs
b) long interfering RNAs
c) short interspersed RNAs
d) long interspersed RNAs
7. The process of RNA inactivation by siRNAs is termed as:
a) RNA silencing
b) RNA interference
c) Short RNA inactivation
d) RNA disfunction
8. DNA _________ is also a method for gene silencing through short RNAs.
9. siRNAs can either be introduced directly or by microinjection. Is the given statement true or false?
10. Introduction into host organism can also be done by using a DNA construct, which when transcribed, generates a RNA which is _________
c) double stranded