Multiple choice question for engineering
1. Bisulphite ions are used to deaminate ________ residues in _______ DNA.
a) C, double stranded
b) C, single stranded
c) U, double stranded
d) U, single stranded
2. For mutagenesis without PCR, which of the following can be used as a template?
a) Single stranded DNA
b) Double stranded DNA
c) Circular DNA
d) Both single and double stranded DNA
3. An oligonucleotide is synthesized which contains the mutation and the rest is _______ to the template DNA.
c) can either be complementary or non-complementary
d) not related
4. If the template is double stranded, they need to be separated before annealing of oligonucleotide. Is the given statement true or false?
5. Which of the following statement is incorrect for synthesis of second strand?
a) The oligonucleotide is acting as a primer for the synthesis of second strand
b) DNA polymerase and dNTPs are added for synthesis
c) The polymerase should have 5’-3’ exonuclease activity
d) A polymerase having 5’-3’ exonuclease activity would degrade the primer that carries the mutant sequence
6. Once the double stranded molecule with mutation is introduced into E. coli for replication, how many types of molecules are produced?
7. How many sites can be mutated at a time?
8. Several different mutations can be induced at one site. Is the given statement true or false?
9. If mixed oligonucleotides are used, it is regarded as:
a) mixed mutagenesis
b) multiple mutagenesis
c) cassette mutagenesis
10. It is easier to subclone a restriction fragment if it belongs to?
a) small gene
b) large gene
c) prokaryotic organism
d) eukaryotic organism
1. The process of finding a particular member of library which is having some defined properties is called as:
2. If for a particular organism sequence data is available and we have to simply search in the data through computer, then this method is called as:
b) database search
c) in silico
d) electronic search
3. If we are having sequence data for a particular organism, but screening is carried out for homologues the program used is BLAST. Is the given statement true or false?
4. If screening is carried out on the basis of sequences which are related to the desired sequence, then the process is called as:
b) homologue search
d) partial search
5. How many techniques are there for carrying out the screening of sequences encoding for RNAs?
6. Choose the incorrect statement for colony or plaque lift.
a) It is the base for screening based on nucleic acid hybridization
b) It is also known as Grunstein-Hogness technique
c) It is based on the fact that which members of the library have the same sequence as the DNA probe
d) The library may be plaques on a bacterial lawn and in that case it is known as plaque lift
7. The screening of libraries us carried out by nucleic acid hybridisation and constitutes of following steps:
i) Peeling of membranes carrying away bacterial cells with it
ii) Cells are lysed and denaturing of DNA is being carried out
iii) Hybridization with labelled DNA
iv) Placing the membrane onto plate containing recombinant cells
Choose the correct sequence in which the steps are carried out (starting to ending).
8. Choose the incorrect statement with respect to the membranes used for adhering of bacterial cells onto them.
a) Nitrocellulose membranes were preferred earlier
b) They bind DNA very efficiently
c) They can be handled easily without breakage
d) They are inflammable
9. Nitrocellulose membranes are less sensitive than nylon membranes. Is the given statement true or false?
10. What is used for lysing of bacterial cells and denaturation of DNA?
b) Sulphuric Acid
c) Sodium Hydroxide
1. Transgenic Drosophila can be created by microinjection of DNA into the embryos. These embryos are at which stage of development?
a) One-cell stage
b) Pre-blastoderm stage
2. Syncytium is a layer of ______ that have not been separated into individual cells.
d) nuclei and cytoplasm
3. In Drosophila, only nuclei cells give rise to germline cells. Is the given statement true or false?
4. ______ integration systems are used for transfer of DNA in Drosophila and it is composed of ______
a) Artificial, P elements
b) Artificial, S elements
c) Natural, P elements
d) Natural, S elements
5. Only the _____ part of Drosophila is transgenic and the rest is not. This is known as ______
a) germline cell, mosaic
b) nurse cells, mosaic
c) germline cells, hybrid
d) nurse cells, hybrid
6. rosy gene is used a selectable marker for transformation in Drosophila, it produces an enzyme required for the synthesis of:
a) wing pigment
b) eye pigment
c) both eye and wing pigment
d) thorax pigment
7. Wild type flies have crimson red eyes whereas rosy mutant have brick-red eyes. Is the given statement true or false?
8. Wild-type Drosophila flies are _____ to ethanol supplied in food.
c) resistant at low concentration and non-resistant at higher concentration
d) resistant at higher concentrations and non-resistant at lower concentration
9. Cis-acting sites should be present in the vector for ________
b) selecting recombinants by acting as a marker
d) providing high copy number
10. The host should ____ P elements, these elements lead to _______
a) not have, instability
b) have, stability
c) not have, increase the time taken for integration
d) have, reduces the time taken for integration
11. Where do P elements integrate in the genome?
a) At specifically defined sites
c) Only at the ends of the genome
d) Integration depends on reaction conditions
12. Transient gene silencing can be carried out by microinjecting ______
a) single stranded RNA
b) double stranded DNA
c) double stranded RNA
d) either double stranded DNA or RNA
1. Enzyme commonly used for carrying out ligation reaction is:
b) Reverse transciptase
2. Which of the following statements is correct with respect to T4 DNA ligase?
a) It can carry out only blunt ended ligations
b) It doesn’t requires ATP
c) It requires a phosphate group at 3’ end and a hydroxyl group at 5’ end for the molecule to be joined
d) It is obtained from T4 bacteriophage upon infection by E. coli
3. If blunt ended ligations are to be carried out. Which of the following enzymes can be used?
a) E. coli DNA ligase
b) T4 DNA ligase
c) Both of these enzymes act equally in carrying out blunt ended ligations
d) None of them is able to carry out blunt ended ligations
4. E. coli DNA ligase doesn’t requires a cofactor. The statement is true or false?
5. Mechanism of ligation for both T4 DNA ligase and E. coli DNA ligase makes use of Adenosine Monophosphate (AMP). Which of the steps is involved in the ligation mechanism?
a) AMP is added to the 5’ phosphate of one of the DNA molecule
b) It leads to liberation of pyrophosphate from NAD and nicotinamide mononucleotide from ATP
c) The AMP is further displaced by an electrophilic attack
d) The AMP is further displaced by nucleophilic attack by 3’ hydroxyl of the same DNA molecule
6. Topoisomerase is also an enzyme which is used for carrying out ligation. The correct statement for topoisomerase is?
a) They act only on double stranded molecules
b) They alter the degree of supercoiling of DNA molecules
c) They are less effective than conventional DNA ligase
d) There are three types of topoisomerases
7. Mobile genetic elements can be transferred from one DNA portion to another. The enzyme carrying out this is:
8. Phage based recombination systems are used for:
a) cleaving the molecules at specific sites
b) adding the molecules at specific sites
c) breakage and rejoining the molecules at specific sites
d) breakage at random sites
9. Bacteriophage lambda is having a phage recombination system. Following are the characteristics of this system:
a) It is used for inserting phage genome into the bacterium
b) It is used for inserting bacterial genome into the phage
c) The specific site in bacteria is attB and that in phage is attP
d) The specific sites in both of them are called as attP
10. Ligation enzymes are used for ligating newly synthesized okazaki fragments. What holds true for okazaki fragments?
a) Okazaki fragments are short fragments of DNA formed on leading strand
b) Okazaki fragments are large fragments of DNA formed on lagging strand
c) Okazaki fragments are short fragments of DNA formed on lagging strand
d) Okazaki fragments are large fragments of DNA formed on leading strand
1. Which of the following statements is correct with respect to exonuclease?
a) They only act on single stranded DNA molecules
b) They only act on double stranded DNA molecules
c) They remove a single nucleotide base at a time
d) They remove nucleotide bases from the middle of polynucleotide chain
2. How many approaches are there which can be used for exonucleolytic activity in double stranded DNA molecules?
3. What is the mode of action of exonuclease III?
a) Exonuclease III acts on single stranded DNA in 3’-5’ direction
b) Exonuclease III acts on double stranded DNA in 5’-3’ direction
c) Exonuclease III acts on single stranded DNA in 5’-3’ direction
d) Exonuclease III acts on double stranded DNA in 3’-5’ direction
4. Which of the following statements is correct regarding S1 nuclease?
a) It acts on double stranded DNA
b) It acts on single stranded DNA
c) It acts on both types of strands
d) It is obtained from E. coli
5. What happens if a DNA molecule is treated by first Exonuclease III and then followed by treatment with S1 nuclease?
a) The molecule is shortened only from 3’ en.
b) The molecule is shortened only from 5’ end
c) The molecule is shortened from both the ends
d) Only Exonuclease acts and S1 doesn’t acts
6. How can one end be protected from the action of Exonuclease III, so that the molecule is not shortened from both the ends?
a) By using Phosphorothioate nucleotide analogue
b) By making both the ends double stranded in nature
c) By labelling one end with a radioactive compound
d) By increasing the time of exposure of the DNA molecule to the enzyme
7. Bal31 is also an enzyme which is used. Which of the following statements hold true in its context?
a) It is having only 3’-5’ exonuclease activity and no endonuclease activity
b) It is having only an endonuclease activity
c) It is having 5’-3’ exonuclease activity
d) It leads to shortening from both the ends
8. The extent of deletions can be manipulated by controlling which of them?
a) Time of incubation only
b) Amount of nuclease added
c) They both have a role to play in the extent of deletion
d) The amount of deletion which can be carried out for a particular amount of DNA is fixed regardless of the amount of nuclease and incubation time
9. What is the function of methylase?
a) Addition of methyl groups to DNA
b) Removal of methyl groups from DNA
c) Both in removal and addition of methyl groups from DNA
d) It is used in production of methane gas
10. Methylase is useful in cloning experiments. True or false?