Biotechnology - Biology Most Important MDCAT MCQs With Explanation

[Shahid]

QUESTION: The DNA that has been altered and which now contains length of nucleotides from two different organisms is called a:
A. Plasmid
B. Combined DNA
C. Vector
D. Recombinant DNA
EXPLANATION
Recombinant DNA technology involves the joining of DNA molecules from two different species. The Recombinant DNA molecule is inserted into a host organism to produce new genetic combinations that are of value to science, medicine, agriculture, and industry.  Vector is basically the in-between to transfer anything from one organism to another. Combined DNA is not even a word.  Plasmid is a small DNA extra found in some bacterium.

QUESTION: It is a method for rapid production of a very large number of copies of a particular fragment of DNA:
A. Gel electrophoresis
B. Polymerase chain reaction
C. DNA extraction
D. Recombination
EXPLANATION
Polymerase chain reaction (PCR) is a technique used to rapidly increase the number of copies of specific regions of DNA for further analyses. The complete process of which is shown below: Image credits: https://www.britannica.com/science/polymerase-chain-reaction

QUESTION: Which of the following is the components / tools of recombinant DNA technology?
A. Gene of interest
B. Molecular scissors
C. Molecular glue and expression system
D. All of the above
EXPLANATION
Recombinant DNA technology makes use of all the molecular components mentioned above, as the main purpose of this technology, in simple words, is to cut a piece of DNA (gene of interest) from a DNA segment, using molecular scissors. This is proceeded by inserting the isolated gene into the DNA of the host organism and by using the molecular glue, it is ensured that the foreign gene segment is permanently placed into the hosts DNA.

QUESTION: Gel electrophoresis is a technique:
A. Employed by forensic scientist to assist in the identification of the individuals by their respective type of DNA
B. Collect all the genes found in one complete set of chromosome
C. Is a technique to separate different sizeds fragment of charge bearing polymers (proteins, RNA or DNA)
D. Grows single cell or a group of cells in a glass ware on artificial medium under aseptic conditions
EXPLANATION
Gel electrophoresis is a laboratory method used to separate mixtures of DNA, RNA, or proteins according to molecular size. In gel electrophoresis, the molecules to be separated are pushed by an electrical field through a gel that contains small pores.

QUESTION: Transgenic organisms:
A. Have a foreign gene inserted into them
B. Have an important role in the large scale production of medicinal products
C. Are considered beneficial to humans
D. All of the above
EXPLANATION
Transgenic organisms have all three characteristics mentioned in options A-C.  They have a foreign gene inserted in them, they play an important role in the large-scale profusion of different types of products like insulin, which is a medicinal commodity. These transgenic organisms are thus considered beneficial to human beings due to the above-stated qualities.

QUESTION: Which of the following is not necessary for PCR to occur?
A. dATP
B. Primers
C. DNA fragments
D. Ribonucleotides
EXPLANATION
Ribonucleotides are fragments required for building up RNA molecules while PCR helps in forming DNA molecules: there is a big difference between the two.  PCR does require DNA fragments to build up the DNA molecules, primers for initiating DNA replication, and dATP to provide adenine nitrogenous bases to the DNA.

QUESTION: The process of determining the locus for particular biological traits includes?
A. Replication
B. Recombination
C. Gene mapping
D. None of these options is correct
EXPLANATION
Gene mapping describes the methods used to identify the locus of a gene and the distances between genes. Gene mapping can also describe the distances between different sites within a gene. The essence of all genome mapping is to place a collection of molecular markers onto their respective positions on the genome.

QUESTION: The genetically engineered vaccine is available for which of the following hepatitis virus?
A. HBV
B. HAV
C. HCV
D. Options A and B are correct
EXPLANATION
Hepatitis A and B currently do have a vaccine but Hepatitis C does not hence the answer is D.

QUESTION: The genetically Engineered vaccine is not available for which of the following?
A. HAV
B. HBV
C. HCV
D. HDV
EXPLANATION
Genetically Engineered vaccines are not available for HCV (Hepatitis C- Virus). It is due to its extreme genetic variability and the lack of small animal models for testing vaccines.

QUESTION: Which of the following characteristics makes plasmid DNA useful for researchers?:
A. Readily incorporate cloned DNA
B. Capable of automatic replication
C. Capable of being isolated from genomic DNA
D. All of these
EXPLANATION
Scientists have taken advantage of plasmids to use them as tools to clone, transfer, and manipulate genes. Therefore, all of these are correct.

QUESTION: Tobacco plants, resistant to a nematode, have been developed by the introduction of DNA that produces (in the host cells):
A. Both sense and anti­sense RNA
B. A particular hormone
C. An antifeedant
D. A toxic protein
EXPLANATION
Many nematodes live in plants and animals including human beings. A nematode Meloidogyne incognita infests the roots of tobacco plants and causes a great reduction in yield. A novel strategy was adopted to prevent this infection that was based on the process of RNA interference (RNAi). RNA interference (RNAi) is the phenomenon of inhibiting the activity of a gene by the synthesis of RNA molecules complementary to the mRNA. The normal (in vivo synthesized) mRNA of a gene is said to be “sense” because it carries the codons that are “read” during translation. Normally, the complement to the mRNA “sense” strand will not contain a sequence of codons that can be translated to produce a functional protein; thus, this complementary strand is called “anti­-sense RNA”. The anti-­sense RNA and mRNA molecules will anneal to form duplex RNA molecules (or double-stranded RNA) and the duplex RNA molecules can not be translated. Thus, the presence of anti­sense RNA will block translation of the mRNA of the affected gene. In fact, recent evidence indicates that these RNA duplexes are often rapidly degraded in vivo.

QUESTION: Golden rice is a promising transgenic crop. When released for cultivation, it will help in
A. Producing a petrol­like fuel from rice
B. Alleviation of vitamin A deficiency
C. Pest resistance
D. Herbicide tolerance
EXPLANATION
Golden rice is a transgenic variety of rice (Oryza sativa) which contains good quantities of B­-carotene (provitamin A-inactive state of vitamin A). B­-carotene is a principal source of vitamin A. The grains of this rice is yellow in colour due to B­-carotene and commonly called golden rice.

QUESTION: During gel electrophoresis, the gel used is:
A. Agar gel
B. Agarose gel
C. Dextran
D. Toluene gel
EXPLANATION
Agarose gel is used during gel electrophoresis. The restriction fragments can be separated according to their length (molecular weight or size) when it is run on the agarose gel.

QUESTION: In prokaryotes only one type of RNA polymerase is present, while ______ types of RNA polymerase are present in eukaryotes.
A. Two
B. Three
C. Four
D. Five
EXPLANATION
Eukaryotic cells contain three distinct nuclear RNA polymerases that transcribe different classes of genes.

QUESTION: Which of the following is NOT true for genes used in recombinant DNA technology?
A. It can isolated from chromosome
B. It can be synthesized chemically
C. It can be made from protein
D. It can be made from mRNA
EXPLANATION
We can use endonuclease enzymes to get genes from chromosomes Genes can be made from proteins using reverse amino acid sequence Genes can be made from mRNA in the traditional process.

QUESTION: A single gene can be amplified by using:
A. DNA fingerprinting
B. Polymerase Chain Reaction
C. Gel Electrophoresis
D. Recombinant DNA technology
EXPLANATION
In research or diagnosis, DNA amplification can be conducted through methods such as Polymerase chain reaction; an easy, cheap, and reliable way to repeatedly replicate a focused segment of DNA by polymerizing nucleotides, a concept that is applicable to numerous fields in modern biology and related sciences.

QUESTION: Which of the following diseases CANNOT be cured by gene therapy?
A. SCID
B. Tuberculosis
C. Cystic fibrosis
D. Cancer
EXPLANATION
Gene therapy is an experimental technique that uses genes to treat or prevent disease. In the future, this technique may allow doctors to treat a disorder by inserting a gene into a patients cells instead of using drugs or surgery. Cancer, unfortunately, cannot be treated by gene therapy.

QUESTION: The cells are held together by a Ca-pectate layer are called as:
A. Primary cell wall
B. Secondary cell wall
C. Middle lamella
D. Tertiary cell wall
EXPLANATION
Plant cell is surrounded by cellulosic cell wall. The cell walls of two adjacent cells are separated by middle lamella which literally means middle plate or middle membrane. Middle lamella is actually the cementing layer between two plant cells. It is absent on the outer surface. It ruptures to create intercellular spaces wherever required. It is formed of calcium and magnesium pectate.

QUESTION: Cloning is a form of:
A. Parthenogenesis
B. Apomixis
C. Sexual reproduction
D. Asexual reproduction
EXPLANATION
Cloning is a type of asexual reproduction that results in offspring that are genetically identical to the parent.

QUESTION: Treatment of hereditary disorders by gene manipulations is called:
A. Biotechnology
B. Genetic engineering
C. Gene therapy
D. None of these
EXPLANATION
With gene therapy, the treatment or elimination of inherited diseases or physical conditions due to these mutations could become a reality. Gene therapy involves the manipulation of genes to fight or prevent diseases.

QUESTION: Vaccination can be done against:
A. Bacterial diseases only
B. Viral diseases only
C. Both Viral and Bacterial
D. All type of disease-causing organisms
EXPLANATION
Live, attenuated vaccines fight viruses and bacteria. Currently, there are no immunotherapeutics or vaccines approved for the treatment or prevention of fungal infections.

QUESTION: DNA fingerprinting is basically done for:
A. DNA cloning
B. DNA analysis
C. DNA sequencing
D. DNA splicing
EXPLANATION
DNA fingerprinting is a laboratory technique used to establish a link between biological evidence and a suspect in a criminal investigation. A DNA sample taken from a crime scene is compared and analyzed with a DNA sample from a suspect. If the two DNA profiles are a match, then the evidence came from that suspect.

QUESTION: Cloning is the production of genetically identical copies of organisms/cells by:
A. Sexual reproduction
B. Asexual reproduction
C. Both sexual and asexual
D. None of the given options
EXPLANATION
Cloning is an asexual method of reproduction, where fertilization or inter-gamete contact does not take place.

QUESTION: Which one of the following options is NOT an example of genetic engineering?
A. Insulin-producing bacteria
B. Oil eating bacteria
C. Photosynthetic bacteria
D. Metal extracting bacteria
EXPLANATION
For bacterias to be photosynthetic they do not need to be genetically programmed. There are naturally occurring photosynthetic bacterias. But, other bacterias such as insulin-producing, oil-eating, and metal extracting ones are those that do not occur naturally; they need to be genetically programmed to do so.

QUESTION: Choose the best group from the following to produce transgenic plants in the laboratory:
A.  Group a
B. Group b
C. Group b and c
D. Group c
EXPLANATION
Group A is correct because it has all the tools required to engineer a plant cell. Restriction enzymes are used to cut out a piece of DNA.DNA ligases are used to engineer, take that cue out gene into the protoplast. Group B is wrong because we do not have plasmids here or any other transmitting agent; plastids are chlorophyll-containing pigments only. Group C can also not be correct for the same reason. Autoradiograph also does not have any function in the engineering of genes in plant cells.

QUESTION: The following picture is of ______ separated on the basis of their size and speed in it
A. Cloning
B. Recombinant DNA technique
C. Cell culture
D. Gel Electrophoresis
EXPLANATION
Gel electrophoresis is a technique used to separate DNA fragments according to their size and speed.DNA samples are loaded into wells (indentations) at one end of a gel, and an electric current is applied to pull them through the gel. DNA fragments are negatively charged, so they move towards the positive electrode.

QUESTION: What is Molecule a in the following picture?
A. Host cell
B. Donor cell
C. Restriction enzyme
D. Recombinant DNA
EXPLANATION
When a piece of DNA from a host is cut out to be inserted into a source DNA to form a combined DNA it is called recombinant DNA.

QUESTION: Choose the term from the following which is NOT a part of gene therapy?
A. Bone marrow transplant
B. Retrovirus
C. DNA Fingerprinting
D. Somatic cells
EXPLANATION
DNA Fingerprinting has nothing to do with gene therapy. Bone marrow transplants, retroviruses, and somatic cells are used to treat patients with mutations in genes. Bone marrow transplant replaces the stem cells in the bone marrow. Retroviruses are used to administer a gene into the cell so that it is incorporated into the DNA. Somatic cell gene therapy involves the placement of a human gene into a living persons somatic cells.

QUESTION: Which of the following is the manipulation of genetic material for practical purposes?
A. Grafting
B. Tissue Culture
C. Genetic Engineering
D. Cell Culture
EXPLANATION
Altering the genetic material by either adding something or removing something from it is called genetic engineering.

QUESTION: The technique use of identification of criminals is called:
A. Cloning
B. DNA fingerprinting
C. Restriction Analysis
D. Polymorphism
E. Gene sequencing
EXPLANATION
DNA fingerprinting is a laboratory technique used to establish a link between biological evidence and a suspect in a criminal investigation. A DNA sample taken from a crime scene is compared with a DNA sample from a suspect. DNA fingerprinting is also used to establish paternity. The figure below shows a DNA fingerprint:

QUESTION: In recombinant DNA technology, the copies of recombinant DNA are increased by:
A. Restriction enzyme
B. Ligase
C. Selection of host with rDNA
D. Multiplication of host with rDNA
EXPLANATION
The copies of recombinatn DNA can be increased by allowing the DNA to replication with host DNA.

QUESTION: Cystic fibrosis patients lack a gene that codes for a transmembrane carrier of:
A. Na+ ions
B. K+ ions
C. CI- ions
D. Ca2+ ions
E. Mg2+ ions
EXPLANATION
Cystic fibrosis is due to the lack of Cl- protein channels which leads to decreased movement of Cl- ions outside the cell, and thus water, leading to thickened mucus.

QUESTION: Cystic fibrosis patients lack a gene that codes for a transmembrane carrier of:
A. Na+ ions
B. K+ ions
C. CI- ions
D. Ca2+ ions
E. Mg2+ ions
EXPLANATION
Cystic fibrosis is due to the lack of Cl- protein channels which leads to decreased movement of Cl- ions outside the cell, and thus water, leading to thickened mucus.

QUESTION: In the commercial manufacture of insulin, a human gene is inserted into which one of the following?
A. A chromosome of a human cell
B. A protein molecule in a yeast cell
C. The DNA of a bacterium
D. The nucleic acid in a virus
EXPLANATION
In commercial manufacture of a human cell, a human gene is inserted into the DNA of a bacterium which then nurtures itself in an environment of its liking producing insulin which is utilized by humans.

QUESTION: The process of replacing or supplementing the defective allele with a functional, normal allele is known as ______.
A. Allele transplant
B. Physiotherapy
C. Gene therapy
D. Mutation
E. Cloning
EXPLANATION
Gene therapy is an experimental technique that uses an allele to treat or prevent disease,by replacing the defective allele. In the future, this technique may allow doctors to treat a disorder by inserting a gene into a patients cells instead of using drugs or surgery.

QUESTION: DNA polymerase enzyme for PCR is isolated from bacteria, Thermus aquaticus, because;
A. It can work at high speed.
B. It can withstand high denaturation temperature.
C. It can withstand low denaturation temperature.
D. It can be used again and again.
EXPLANATION
Thermos aquaticus is a heat-tolerant bacterium and its enzymes, including DNA polymerase (or Taq polymerase), are resistant to high temperatures. In PCR, a high temperature is used (denaturation temperature) to denature the template DNA or separate its strands. The fact that this DNA polymerase can withstand the high temperatures, used in PCR, enables it to work efficiently without denaturing itself, thereby enabling the reaction to occur, adequately. Hence, option B is the correct answer. Option A is not exclusive to this enzyme, as most enzymes can work at a high speed and increase the rate of reaction. Option C is technically correct as if this DNA polymerase can withstand high temperature, it can obviously withstand low temperature as well, but since PCR involves a high temperature, this trait is not relevant to the scenario. Option D is a feature shared by all enzymes as they are recyclable, not exclusive to this DNA polymerase.

QUESTION: Genetic engineering has been successfully used for producing;
A. Animals, with inferior traits.
B. Transgenic mice for testing safety of polio vaccine before use in humans
C. Animals, that have the same genetic constitution.
D. None of the above
EXPLANATION
Transgenic mice are being formed for use in testing the safety of vaccines before they are used on human beings. Transgenic mice are being used to test the safety of the polio vaccine. Many transgenic animals are developed to increase our understanding of how genes contribute to the development of disease so, that investigation of new treatments for diseases is made possible. Now transgenic models exist for many human diseases such as cancer, cystic fibrosis, rheumatoid arthritis, Alzheimers disease, hemophilia, thalassemia, etc. Therefore, the correct answer is option B.

QUESTION: The Plasmid pBR322 has antibiotic resistance genes for:
A. Streptomycin
B. Ampicillin and Tetracycline
C. Tetracycline and mxycycline
D. Ampicillin
EXPLANATION
Factual recall; pBR322 is base pairs in length and has two antibiotic resistance genes - the gene bla, encoding the ampicillin resistance (AmpR) protein, and the gene tetA, encoding the tetracycline resistance (TetR) protein.

QUESTION: Chemical nature of primers used in the PCR process is _______.
A. RNA
B. Protein
C. Carbohydrate
D. DNA
EXPLANATION
PCR primers are short pieces of single-stranded DNA, usually around 20 nucleotides in length

QUESTION: DNA made by joining pieces from two or more different sources:
A. Probes
B. Restriction endonuclease
C. Mutated DNA
D. Recombinant DNA
EXPLANATION
Recombinant DNA (or rDNA) is made by combining DNA from two or more sources. DNA probes are stretches of single-stranded DNA used to detect the presence of complementary nucleic acid sequences (target sequences) by hybridization. A restriction enzyme, restriction endonuclease, or restrictase is an enzyme that cleaves DNA into fragments at or near specific recognition sites within molecules known as restriction sites. A mutation is a change in a DNA sequence. Mutations can result from DNA copying mistakes made during cell division, exposure to ionizing radiation, exposure to chemicals called mutagens, or infection by viruses.

QUESTION: By PCR we mean:
A. Polymerase chronic reaction
B. Polymerase chain reaction
C. Polymerase copy reaction
D. Polymerase cross reaction
EXPLANATION
Fact

QUESTION: Deficiency of enzyme ______ causes combined immunodeficiency syndrome.
A. Adenosine transcriptase
B. Adenosine transaminase
C. Adenosine polymerase
D. Adenosine deaminase
EXPLANATION
Adenosine deaminase deficiency (ADA deficiency) is an inherited condition that damages the immune system and is a common cause of severe combined immunodeficiency (SCID).

QUESTION: Enzyme used by the Bacteria to cut the DNA of the invading Virus for its protection is:
A. Restriction Exonuclease
B. Restriction Ligase
C. Restriction Endonuclease
D. DNA polymerase
EXPLANATION
Restriction enzyme, also called restriction endonuclease, a protein produced by bacteria that cleaves DNA at specific sites along the molecule. In the bacterial cell, restriction enzymes cleave foreign DNA, thus eliminating infecting organisms. Specific endonucleases, also called restriction endonucleases, are available that cleave specific sites within a DNA sequence. Exonuclease is usually non-specific and does not have defensive properties against the entry of pathogenic microbes. Ligase is an enzyme that uses ATP to form bonds, and is used in recombinant DNA cloning to join restriction endonuclease fragments that have annealed. (There is no such thing as restriction ligase) A DNA polymerase is a member of a family of enzymes that catalyze the synthesis of DNA molecules from nucleoside triphosphates, the molecular precursors of DNA.

QUESTION:  Among the following, which one is commonly used as a restriction enzyme:
A. pBr 101
B. EcoR1
C. EcoR3
D. Both pBr 101 and EcoR3
EXPLANATION
EcoRI is a restriction endonuclease enzyme isolated from species E. coli. It is a restriction enzyme that cleaves DNA double helices into fragments at specific sites, and is also a part of the restriction modification system. Like all enzymes, a restriction enzyme works by shape-to-shape matching. When it comes into contact with a DNA sequence with a shape that matches a part of the enzyme, called the recognition site, it wraps around the DNA and causes a break in both strands of the DNA molecule.

QUESTION: DNA Polymerase synthesize DNA from _________:
A. RNA
B. Eco R1
C. Template RNA
D. Template DNA
EXPLANATION
Since DNA polymerase requires a free 3 OH group for initiation of synthesis, it can synthesize in only one direction by extending the 3 end of the preexisting nucleotide chain. Hence, DNA polymerase moves along the template strand in a 3–5 direction, and the daughter strand is formed in a 5–3 direction

QUESTION: DNA polymerase is a temperature insensitive enzyme extracted from:
A. Fishelsoni
B. Thermus aquaticus
C. E. Coli
D.  Both Fishelsoni and Thermus aquaticus
EXPLANATION
Thermus aquaticus is a bacterium that lives in hot springs and hydrothermal vents, and Taq polymerase was identified as an enzyme able to withstand the protein-denaturing conditions like high temperature required during PCR. Therefore is the source of the DNA polymerase used in PCR technique.

QUESTION: Method of producing thousands of seedlings is:
A. PCR
B. Tissue Culture
C. Micropropagation
D. Macropropagation
EXPLANATION
The method of growing or producing thousands of plants through tissue culture is called micropropagation.

QUESTION: Gene can be made from mRNA using:
A.  PCR
B. PBr 103
C. Eco R1
D. Reverse transcriptase
EXPLANATION
Reverse transcriptase (RT), also known as RNA-dependent DNA polymerase, is a DNA polymerase enzyme that transcribes single-stranded RNA into DNA.

QUESTION: Passive immunity is used against:
A. Malaria
B. Typhoid
C. Dengue
D. Tetanus
EXPLANATION
Tetanus immune globulin (TIG) is used to provide passive immunity for patients whose immunisation is incomplete, or if it is unsure whether 10 years have elapsed since the last dose of the tetanus toxoid.

QUESTION: Bacterial cells take up recombinant plasmids when they are treated with:
A. CaCl2
B. NaCl
C. KCl
D. NaOH
EXPLANATION
Adding CaCl2 encourages the binding of plasmids to lipopolysaccharides, allowing the recombinant plasmid to enter the cell during heat shock.

QUESTION: Which one of the following is made up of radioactively labelled nucleotides?
A. Phage DNA
B. Genomic Library
C. Recombinant DNA
D. Gene Probe
EXPLANATION
Gene probes are labelled with radioactive or chemical tags which allow its binding with other nucleic acids to be visualised.

QUESTION: A technique in transgenic animals in which desired gene is inserted into the eggs of animal is called:
A. Embryonic Stem Cell mediated Transfer
B. Microinjection
C. Retro-virus mediated gene Transfer
D. Virus vectors
EXPLANATION
Direct injection of a chosen gene into a fertilised egg is known as DNA microinjection.

QUESTION: Which one of the following edible products is widely pasteurized?
A. Soft drinks
B. Mango squash
C. Milk
D. Orange Juice
EXPLANATION
Milk undergoes a bacteria-killing process known as pasteurization, to ensure it is safe to consume.

QUESTION: The plants having foreign DNA incorporated into their cells are called:
A. Colonal plants
B. Transgenic plants
C. Bio tech plants
D. Tissue cultured plants
EXPLANATION
The term transgenic indicates an organism that contains genetic material from a foreign source

QUESTION: Pasteurization technique is widely used for preservation of:
A. Water
B. Heat
C. Milk products
D. Vaccines
EXPLANATION
Pasteurization is a technique to remove pathogenic organisms in certain foods and liquids. In water, bacteria is killed through the process of chlorination. Hence, the only remaining viable option is option C : Milk products.

QUESTION: The agent which separates the two strands of DNA in PCR is??
A. DNA ligase
B. Primer
C. Heat
D. Helicase
EXPLANATION
The first step of PCR involves heating the solution to between 90 and 100 Degrees Celsius, thereby breaking the Hydrogen bonds between complementary base pairs.

QUESTION: Cystic fibrosis patient lack a gene that codes for trans-membrane carrier of?
A. Na+ ions
B. Cl- ions
C. Ca++ ions
D. K+ ions
EXPLANATION
Cystic fibrosis patients lack a gene that codes for the trans-membrane carrier of the chloride ion. (PTB)

QUESTION: The phage commonly used as a vector in genetic engineering is?
A. Lambda phage
B. Gamma phage
C. T2 phage
D. T4 phage
EXPLANATION
Modified Lambda phages are used as a vector to introduce foreign DNA into a cell due to their efficiency at packaging and injecting DNA into the cell.

QUESTION: Restriction endonucleases are naturally occurring enzymes of:
A. Viruses
B. Bacteria
C. Fungi
D. Plants
EXPLANATION
Restriction endonucleases cleave into fragments near or at recognition sites. They are found in bacteria as a defence mechanism against viruses.

QUESTION: In recombinant DNA technology _________ are tools for manipulating DNA
A. Viruses
B. Chromosomes
C. Enzymes
D. Genes
EXPLANATION
Enzymes are essential to DNA recombinant technology, and help modify and change DNA molecules as per need.

QUESTION: In DNA finger printing process, the use of __________ produces distinctive pattern on autoradiography or X-ray film
A. Restriction enzyme
B. Microsatellites
C. Macrosatellites
D. Probes for genetic markers
EXPLANATION
in DNA fingerprinting, probes for genetic markers are uses to identify markers such as microsatellites, and thus produce distinctive patterns on autoradiography and x-ray films.

QUESTION: In the recombinant DNA technology plasmids are used as
A. Genetic material
B. Enzymes
C. Vectors
D. Probes
EXPLANATION
Plasmids are small, circular, double-stranded DNA molecules, which are used in DNA recombinant technology by modifying the plasmid and then introducing them into cells

QUESTION:  In which process, multiple copies of the desired genes are produced?
A. Polymerase chain reaction
B. Gene sequencing
C. Analyzing DNA
D. DNA finger printing
EXPLANATION
Polymerase chain reactions are used by molecular biologists to replicate a few or even a singular DNA molecule into millions of copies.

QUESTION: The enzyme adenosine deaminase is missing in person suffering from:
A. Cystic fibrosis
B. Hypercholesterolemia
C. Severe combined immunodeficiency syndrome
D. Parkinson’s disease
EXPLANATION
Adenosine deaminase deficiency is an inherited disorder, which causes severe combined immunodeficiency syndrome, and it causes the afflicted person to have virtually no immunity to bacteria, viruses or fungi.

QUESTION: The first microbe to have the genome completely sequenced and was published on July 28th, 1995 was
A. Hyphomicrobium
B. Haemophilus aquaticus
C. Haemophillus malariae
D. Haemophillus infulenzae
EXPLANATION
Option A is incorrect because this microbe was not used to sequence the genome Option B is incorrect because this microbe was not used to sequence the genome Option C is incorrect because this microbe was not used to sequence the genome Option A, B and C are incorrect since the given microbe was not used the first one to have complete squence. Option D is correct since Haemophilus influenzae was first microbe to sequence the genome

QUESTION: The common vectors used in recombinant DNA technology are:
A. Probes
B. Palindromes
C. Plasmids
D. Prions
EXPLANATION
Plasmids are small, circular, double-stranded DNA molecules, which are used in DNA recombinant technology by modifying the plasmid and then introducing them into cells.

QUESTION: The enzyme used to isolate gene from DNA is:
A. Helicase
B. Reverse Transcriptase
C. Restriction Enzyme
D. DNA Polymerase
EXPLANATION
Restriction enzymes are used to separate DNA molecules at specific points, and can be used to separate specific genes.

QUESTION: Which one of the following enzymes is temperature insensitive?
A. DNA Polymerase I
B. Taq Polymerase
C. DNA Polymerase III
D. RNA Polymerase
EXPLANATION
Taq polymerase is an enzyme used in DNA synthesis and proves to be most active at 70 to 80 degree Celsius, and can function even near 100 degree celsius.

QUESTION: Liposomes are used in gene therapy against
A. Hypercholesterolemia
B. Coronary Artery Angioplasty
C. Cystic Fibrosis
D. Severe Combined Immunodeficiency Syndrome (SCID)
EXPLANATION
Gene therapy using liposomes is used to treat cystic fibrosis. Liposomes are microscopic vesicles of lipoproteins, used to deliver the normal gene into the patients cells.

QUESTION: Genetically engineered cells are introduced into bone marrow cells in the treatment of
A. Hypercholesterolemia
B. Severe Combined Immunodeficiency Syndrome (SCID)
C. Cystic Fibrosis
D. Coronary Artery Angioplasty
EXPLANATION
Gene therapy for SCID involves the removal of bone marrow stem cells from the patient. These cells are injected with the with a retrovirus which carries the normal gene into the cells. The stem cells are returned to the patient, and they start producing the needed enzyme.

QUESTION: All of the following acts as cloning vector except
A. BAC
B. YAC
C. Cosmids
D. EcoRI
EXPLANATION
BAC, YAC, Cosmids acts as cloning vector except EcoRI

QUESTION: Which of the following is the suitable vector to be incorporated with the large external DNA fragment?
A. Small size vector
B. Large size vector
C. Large size vector with no origin of replication.
D. Small size vector with no origin of replication.
EXPLANATION
In molecular cloning, a vector is a DNA molecule used as a vehicle to artificially carry foreign genetic material into another cell, where it can be replicated and/or expressed. A vector containing foreign DNA is termed recombinant DNA. A small size is the suitable vector to be incorporated with the large external DNA fragment because it should be small in size so that it can easily integrate into the host cell. It should be capable of inserting a large segment of DNA. It should possess multiple cloning sites.

QUESTION: For the location / detection of a gene in a DNA library which of the following is used ?
A. Primer
B. Probe
C. Restriction enzyme
D. Taq Polymerase
EXPLANATION
Aprobe is a single-stranded sequence of DNA or RNA used to search for its complementary sequence in a sample genome. DNA probes are important tools in diagnostics to ensure high specificity and sensitivity. They are used in molecular biology methods like PCR. Fluorescence in situ hybridization (FISH) is a laboratory technique for detecting and locating a specific DNA sequence on a chromosome. The technique relies on exposing chromosomes to a small DNA sequence called a probe that has a fluorescent molecule attached to it.

QUESTION: Under UV illuminator, DNA bands are seen in agarose gel due to which of the following?
A. Agarose
B. Charge in DNA
C. Fluorescent dye
D. Radioactive dye
EXPLANATION
Fluorescent dyes, also known as reactive dyes or fluorophores are used for locating dna bands. Fluorescence is used in biology as a non-destructive way of analysing biological molecules, even at low concentrations, by means of the molecules intrinsic fluorescence, or by attaching it with a fluorophore therefore dna bands can easily be seen.

QUESTION: What will happen if a vector (plasmid) is cut with a different restriction enzyme which cuts the external DNA to be incorporated in the vector (plasmid) ?
A. Ligation
B. No ligation
C. Tight ligation
D. Cloning
EXPLANATION
The DNA ligase catalyzes the formation of covalent phosphodiester linkages, which permanently join the nucleotides together. After ligation, the insert DNA is physically attached to the backbone and the complete plasmid can be transformed into bacterial cells for propagation so if vector is cut by different restrict]tion enzyme ligation occurs.