Olete.in – MCQs, Mock Tests & Government Job Prep | Biotechnology Biotechnology MCQ set-2

What are the effects of increasing concentration of reaction components?

1. It increases chances of ligation in both intramolecular and intermolecular reactions
2. It increases chances of ligation only in intermolecular and no effect on intramolecular
3. It decreases chances of ligation in intramolecular and increases in that of intermolecular
4. It decreases chances of ligation in both types of reaction

✅ Correct Answer: 2

Enzyme commonly used for carrying out ligation reaction is ____________

1. Transferase
2. Reverse transciptase
3. Ligase
4. DNase

✅ Correct Answer: 3

Which of the following statements is correct with respect to T4 DNA ligase?

1. It can carry out only blunt ended ligations
2. It doesn’t requires ATP
3. It requires a phosphate group at 3’ end and a hydroxyl group at 5’ end for the molecule to be joined
4. It is obtained from T4 bacteriophage upon infection by E. coli

✅ Correct Answer: 4

If blunt ended ligations are to be carried out. Which of the following enzymes can be used?

1. E. coli DNA ligase
2. T4 DNA ligase
3. Both of these enzymes act equally in carrying out blunt ended ligations
4. None of them is able to carry out blunt ended ligations

✅ Correct Answer: 2

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?

1. AMP is added to the 5’ phosphate of one of the DNA molecule
2. It leads to the liberation of pyrophosphate from NAD and nicotinamide mononucleotide from ATP
3. The AMP is further displaced by an electrophilic attack
4. The AMP is further displaced by nucleophilic attack by 3’ hydroxyl of the same DNA molecule

✅ Correct Answer: 1

Topoisomerase is also an enzyme which is used for carrying out ligation. The correct statement for topoisomerase is?

1. They act only on double stranded molecules
2. They alter the degree of supercoiling of DNA molecules
3. They are less effective than conventional DNA ligase
4. There are three types of topoisomerases

✅ Correct Answer: 2

Phage based recombination systems are used for ____________

1. cleaving the molecules at specific sites
2. adding the molecules at specific sites
3. breakage and rejoining the molecules at specific sites
4. breakage at random sites

✅ Correct Answer: 3

Bacteriophage lambda is having a phage recombination system. Following are the characteristics of this system ____________

1. It is used for inserting phage genome into the bacterium
2. It is used for inserting bacterial genome into the phage
3. The specific site in bacteria is attB and that in phage is attP
4. The specific sites in both of them are called as attP

✅ Correct Answer: 1

Ligation enzymes are used for ligating newly synthesized okazaki fragments. What holds true for okazaki fragments?

1. Okazaki fragments are short fragments of DNA formed on the leading strand
2. Okazaki fragments are large fragments of DNA formed on the lagging strand
3. Okazaki fragments are short fragments of DNA formed on the lagging strand
4. Okazaki fragments are large fragments of DNA formed on the leading strand

✅ Correct Answer: 3

Introduction of DNA molecules into the recipient organism is termed as ____________

1. transformation
2. translation
3. transduction
4. transcription

✅ Correct Answer: 1

Many bacterial species are having a natural ability to take up the exogenous DNA material. Which of the statement is not correct in regard to it?

1. This ability is termed as competence
2. It is not limited to particular growth phases
3. The bacteria may develop new biochemical abilities under special conditions such as nutrient deprivation
4. Induction of specific set of bacterial proteins may take place

✅ Correct Answer: 2

Which of the statements hold true for conjugation?

1. Conjugation is the natural process of transferring DNA from one species to another
2. It is the artificial process in case the cells are not able to take them up naturally
3. The plasmids are transferred from one cell to another by physical contact
4. The plasmids are transferred from one cell to another by chemical means

✅ Correct Answer: 2

F plasmid is often used in conjugation. The correct statement is?

1. The F plasmid encodes the factor which is transferred from one cell to another
2. The factor encoded by the F plasmid is called as Filamentous (F) factor
3. It is transferred from one cell to another by filament
4. The bacteria must belong to same species to carry out the conjugation

✅ Correct Answer: 1

Plasmids can be classified into how many types depending on the genes present for their transformation?

1. 1
2. 2
3. 3
4. 4

✅ Correct Answer: 2

Chemical transformation refers to the methods which use chemicals in order to carry out transformation. Which of the following statements is true with respect to it?

1. Chemical transformation decreases the efficiency of transformation as compared to natural transformation
2. Ice cold calcium solution followed by heat shock is responsible for affecting the efficiency of DNA uptake
3. The mechanism responsible for it named as ‘the heat shock model’
4. Other complex mixtures such as those containing Manganese and hexamine cobalt can’t be used to affect the efficiency

✅ Correct Answer: 2

Electroporation is also used for taking up the DNA by the cells. It constitutes of ____________

1. inserting the DNA into the cells via an electric shock
2. increased efficiency than both natural and chemical methods
3. causing the least amount of damage in comparison to other methods
4. decreased efficiency than both natural and chemical methods

✅ Correct Answer: 1

Transformation carried out using a particle gun is known as biolistic transformation. It falls under which category of transformation?

1. Physical
2. Chemical
3. Electroporation
4. Natural

✅ Correct Answer: 1

The particle gun method consists of which of the following steps?

1. The DNA of interest is absorbed onto microprojectile beads
2. These beads are often made of aluminium
3. The explosion in a gun propels a macroprojectile forward which in turn propels microprojectile beads
4. The macroprojectiles and microprojectiles both cross the perforated plate and hit the target tissue behind it

✅ Correct Answer: 3

Isolation of genomic DNA follows the same principles as that of obtaining plasmid from E. coli. Which of the following is not included in it?

1. Cell lysis
2. Removal of proteins
3. Removal of chromosomal DNA
4. Dissolving plasmid in water

✅ Correct Answer: 4

How many methods are there for obtaining the plasmid DNA from the bacteria?

1. 1
2. 2
3. 3
4. 4

✅ Correct Answer: 2

Cell lysis is carried out by which substance?

1. Lysozyme and detergents
2. Water
3. Sugar solution
4. Suphuric Acid

✅ Correct Answer: 1

Chromosomal or genomic DNA is separated by ____________

1. Sedimentation
2. Dissolution in water
3. Centrifugation
4. Distillation

✅ Correct Answer: 3

Proteins can be removed via treatment by?

1. Phenol and chloroform treatment
2. Treatment with sodium hydroxide
3. Chloroform treatment alone
4. Centrifuging

✅ Correct Answer: 1

Nucleic acid precipitated constitutes of ____________

1. plasmid DNA
2. plasmid DNA, along with RNA and chromosomal DNA
3. rna alone
4. chromosomal DNA only

✅ Correct Answer: 2

Treatment with exonuclease leads to removal of ____________

1. remnants of chromosomal DNA
2. RNase
3. plasmid DNA which is circularized
4. proteins

✅ Correct Answer: 1

Adsorption onto a solid phase support followed by elution is used as an alternative for separation of which component?

1. chromosomal DNA
2. plasmid DNA
3. RNA alone
4. other impurities

✅ Correct Answer: 2

Which of the following components bind to the solid column made of silica, under high salt concentration?

1. Proteins
2. Polysaccharides
3. Both proteins and polysaccharides
4. Plasmid DNA

✅ Correct Answer: 4

Purification of DNA by using silica derivatized groups by DEAE is termed as ____________

1. ion exchange resin based method.
2. silica based purification
3. atom based resin exchange method
4. packed bed purification

✅ Correct Answer: 1

Which of the following is correct with respect to caesium chloride centrifugation?

1. Caesium is light in weight
2. The dissolution of caesium and nucleic acids leads to the formation of gradients
3. According to the amount of supercoiling and A+T content, the DNA settles
4. Nicked DNA settles below than supercoiled DNA

✅ Correct Answer: 2

Which of the following components settles at the bottom?

1. RNA
2. Proteins
3. Nicked DNA
4. Supercoiled DNA

✅ Correct Answer: 1

The location of plasmid DNA can be visualized by addition of:

1. bromophenol blue
2. ethidium bromide
3. ortho xylene
4. texas red

✅ Correct Answer: 2

Sand does not show any bulking when:

1. Completely saturated
2. Partially saturated
3. Contains small amount of impurities
4. Voids are partially filled with air

✅ Correct Answer: 1

What effect does bulking have on fresh concrete?

1. Strength reduces
2. Shrinkage increases
3. Volume reduces
4. Workability increases

✅ Correct Answer: 4

Why is natural cement used very limitedly?

1. Brown in Colour
2. Standard consistency is not met with
3. Sets too quickly
4. Particle size is too fine

✅ Correct Answer: 3

Who invented Portland cement and in which year?

1. William Aspdin, 1824
2. William Aspdin, 1840s
3. Joseph Aspdin, 1840s
4. Joseph Aspdin, 1824

✅ Correct Answer: 2

What is the average particle size of cement?

1. 15 microns
2. 45 microns
3. 75 microns
4. 100 microns

✅ Correct Answer: 1

What is the meaning of soundness of cement?

1. Ability to flow when mixed
2. Ability to make ringing noise when struck
3. Ability to form strong and sound structure
4. Ability to retain volume after setting.

✅ Correct Answer: 4

Time elapsed from the instance of adding water until paste ceases to behave as fluid is called:

1. Initial setting time
2. Final setting time
3. Intermediate setting time
4. Absolute setting time

✅ Correct Answer: 1

Which of the below mentioned is not a result of field test performed on cement?

1. There should not be any lumps
2. It should feel cold when you put your hand in bag of cement
3. The colour should be blackish grey
4. It should not be gritty when rubbed with finger

✅ Correct Answer: 3

Which equipment is used to test the setting time of cement?

1. Core cutter
2. Vibrator
3. Universal testing machine (UTM)
4. Vicat apparatus

✅ Correct Answer: 4

What is the initial setting time of cement?

1. 1 hour
2. 30 minutes
3. 15 minutes
4. 30 hours

✅ Correct Answer: 2

Use of coarser cement particles leads to:

1. Low durability
2. Higher strength
3. Low consistency
4. Higher soundness

✅ Correct Answer: 1

Green cement is:

1. Green coloured cement
2. Cement mixed with plant products
3. Cement mixed with recycled materials
4. Cement mixed with green algae

✅ Correct Answer: 3

What is the depth the needle in Vicat apparatus should penetrate into the cement paste in consistency test?

1. 33-35 cm from bottom of the mould
2. 33-35 mm from top of the mould
3. 33-35 cm from top of the mould
4. 33-35 mm from bottom of the mould

✅ Correct Answer: 2

What is the most dominant constituent of cement?

1. Silica
2. Lime
3. Magnesia
4. Alumina

✅ Correct Answer: 2

Deficiency of lime in cement leads to:

1. Unsound cement
2. Disintegration of cement
3. Quick setting of cement
4. Expansion of cement

✅ Correct Answer: 3

What effect does calcium sulphate have on cement?

1. Retards setting action
2. Acts as flux
3. Imparts colour
4. Reduces strength

✅ Correct Answer: 1

Which of the following adds a quick-setting property to cement?

1. Magnesium oxide
2. Silicon dioxide
3. Iron oxide
4. Aluminium oxide

✅ Correct Answer: 4

Which of the following imparts greenish grey colour to cement?

1. Calcium silicate
2. Calcium aluminate
3. Calcium aluminate ferrite
4. Calcium carbonate

✅ Correct Answer: 3

Excess of Alkali in cement results in:

1. Dry cement paste
2. Efflorescence
3. Less plasticity
4. Unsound cement

✅ Correct Answer: 2