Genetic modification and biotechnology - class-VII

The final step of PCR is the extension, wherein Taq DNA polymerase is isolated from a thermophilic bacterium Thermus aquaticus.

Polymerase chain reaction is a technique used for amplification of DNA fragments. Its amplification cycle involve three steps - denaturation, annealing and polymerisation which are repeated for 'n', cycles.

The final step of PCR is the extension, wherein Taq DNA polymerase (isolated from a thermophilic bacterium Thermus aquaticus) synthesizes the DNA region between the primers, using dNTPs (deoxynucleoside triphosphates) and $Mg^{2+}$. The primers are extended towards each other so that the DNA segment lying between the two primers is copied. The optimum temperature for this polymerisation step is $72^o$$C$. Taq polymerase remains active during high temperature-induced denaturation of double-stranded DNA.

Process used for amplification or multiplication of DNA in DNA fingerprinting is Polymerase chain reaction (PCR) .It is done in invitro system.

The cost of gene cloning is far more than PCR because gene cloning requires many intricate steps. PCR takes less than 4 hours while gene cloning can take days.

In addition to Tag DNA polymerase, Pfu polymerase and Tli polymerase have been isolated which are also thermostable. Pfu polymerase is isolated from Pyrococcus furiosus. Tli (vent) polymerase is isolated from Thermococcus litoralis.

PCR is a method for DNA amplification, not DNA staining. DNA staining is typically performed using dyes like ethidium bromide or SYBR Green.

Very low count of bacteria or viruses (when the symptoms of the disease are not yet visible) can be detected by multiplication of their nucleic acid by PCR, (PCR can detect very low amounts of DNA). PCR is usually used to detect HIV in suspected AIDS patients.

Polymerase chain reaction involves the steps:

Antibiotic resistance genes are selectable markers. Desirable genes are the ones which are introduced in the vector for getting desired protein product. In agarose gel electrophoresis, DNA fragments are separated according to their charge and size. After the formation of the product in a bioreactors, it undergoes through some processes before a finished product is ready for marketing. The processes include separation and purification of products which are collectively called as downstream processing.

In 1985 Norm Arnheim, also a member of the development team concluded his sabbatical at Cetus and assumed an academic position at USC. He began to investigate the use of PCR to amplify samples containing just a single copy of the target sequence. By 1989 his lab developed multiplex-PCR on single sperm to directly analyze the products of meiotic recombination.

The development of molecular techniques that access viral load and the development of genotypic resistance have revolutionized the treatment of HIV disease. Commercially available viral load assays use a number of different approaches from reverse transcriptase PCR to amplification of branched chain DNA. New real-time PCR assays are under development, including LightCycler- and TaqMan-based tests.
So, the correct answer is option A. ( X=PCR ).

Kary Mullis. Kary Banks Mullis (born December 28, 1944) is a Nobel Prize-winning American biochemist. In recognition of his invention of the polymerase chain reaction (PCR) technique, he shared the 1993 Nobel Prize in Chemistry with Michael Smith and earned the Japan Prize in the same year.

Translation is the process of synthesis of protein using mRNA nucleotide sequence as template, it occurs in cytoplasm. Transcription is the process of mRNA synthesis using DNA coding strand as template, it occurs in nucleus. PCR is a technique to amplify the gene of interest in three steps namely denaturation of target DNA (thermal cycle to separate the DNA strands), annealing of primers to the ssDNA and polymerisation (extension of primer into complete DNA strand complementary to the template strand). After completion of one cycle of PCR, two copies of the target DNA are produced both of which serve as template for next PCR cycle and produce 4 copies. Hence, there is exponential amplification of DNA copies. Correct option is C.

Polymerase chain reaction (PCR) is a method widely used in molecular biology to make many copies of a specific DNA segment. Using PCR, a single copy (or more) of a DNA sequence is exponentially amplified to generate thousands to millions of more copies of that particular DNA segment.

DNA polymerase enzyme was isolated from a thermophilc bacteria called Thermus aquaticus. This is an enzyme used frequently to make multiple copies of segment of DNA by a technique called polymerase chain reaction.

The denaturation stage of PCR takes about 1–2 minutes. The thermocycler then lowers the temperature to about 50° to 60°C, which allows the short, oligonucleotide primers to anneal to their complementary sequences on the single-stranded DNA molecules. The annealing stage of PCR lasts about 30 seconds. Hence, the whole cycle of gene amplification requires 30 minutes.

PCR requires a thermostable DNA polymerase to synthesize new DNA strands during the extension phase. Taq polymerase, isolated from Thermus aquaticus, is the standard enzyme used because it withstands high temperatures.

A thermal cycler is an instrument used to perform PCR by precisely controlling the temperature changes required for denaturation, annealing, and extension.

PCR is a technique for amplifying DNA in vitro. It is not a method for transferring DNA into a host cell; methods like microinjection, gene guns, and vectors are used for transformation.

PCR is specifically designed to amplify a specific DNA sequence, producing billions of copies from a small starting amount of template DNA.

Polymerase chain reaction (PCR) is a technique that exponentially amplifies a single copy of a specific DNA segment. It generates thousands of copies of that specific DNA segment. After completion of one cycle, 2 copies are produced from a single DNA segment. After completion of the second cycle, 2$^2$ = 4 copies are produced. Similarly, after n$^{th}$ cycle, 2$^2$ copies are produced, where n is the number of cycles. Hence, after completion of 6 cycle, 2$^6$ = 64 copies will be produced. 

Polymerase Chain Reaction (PCR) is widely used the method in genetic engineering to prepare the multiple copies of desired DNA. It includes steps of denaturation, annealing extension and last amplification. As DNA is the polymer of four DNA bases present in the base pair and polymerase chain reaction is done in the presence of DNA polymerase enzyme of the DNA that re-studies by the researchers which is said to be DNA library so it is not required in the reaction.

A primer is a short single strand of RNA or DNA (generally about 18-22 bases) that serves as a starting point for DNA synthesis. It is required for DNA replication because the enzymes that catalyze this process, DNA polymerases, can only add new nucleotides to an existing strand of DNA. The polymerase starts replication at the 3′-end of the primer, and copies the opposite strand. 

A DNA sequencing reaction was performed with the fragment 5−XXXGCGATCGYYYY−3′ as the template, dideoxy GTP, all the four dNTPs, and the required primers and enzyme. XXXX and YYYY in the given DNA fragment represent primer binding sites. The set of fragments obtained during the reaction will be CGATCGC, because if primer is attache to the XXXX binding site it polymerization starts and its complimentary fragment is CGATCGC.

• Agarose is derived from seaweeds Gelidium and Gracilaria
• Opine synthesis is the function of Ti plasmid of Agrobacterium
• Biolistic is the term used for gene gun used for biotransformation
• Thermocycler is used to carry out PCR reaction

The areas of application of PCR include 

PCR detects genetic material (DNA/RNA). Antigen-antibody interactions are detected using techniques like ELISA, not PCR.

While fermentation is an ancient biotechnological process, in the context of modern molecular biotechnology, PCR and its application in disease detection are often cited as foundational developments.

The sequence 5'-GAATTC-3' paired with 3'-CTTAAG-5' is the classic palindromic recognition site for the restriction enzyme EcoRI, which cuts between G and A.

PCR stands for Polymerase Chain Reaction, a technique used to amplify specific segments of DNA.

Answer is option C i.e. "Gel electrophoresis"
Gel electrophoresis is the technique which can check DNA fragment progression. Restriction enzyme digest DNA into fragments. Each fragment has different size. When gel electrophoresis is performed each fragment with different sizes are separated on the gel.
While, PCR is used for DNA amplification. Bioreactors are the fermentors used for fermentation process and micro-injection is a method used to transfer genes between animals.

DNA primer is not required for a PCR reaction. 

• Nucleotides are compound consisting of a nucleoside linked to a phosphate group. Nucleotides form the basic structural unit of nucleic acids such as DNA and RNA. For example, Adenylic acid, Guanylic acid, Thymidylic acid, and Cytidilic acid and 5'uridylic acid.
• Hence Adenylic acid, Cytidilic acid, Guanylic acid are all Nucleotides.
• So, the correct answer is 'Adenylic acid, Cytidilic acid, Guanylic acid'.

DNA polymerase enzyme synthesizes DNA strands by adding deoxyribonucleotides to 3' end of the primer via phosphodiester bonds; it uses parental DNA as a template. Kary Mullis got Nobel prize, in 1993 in chemistry, for the invention of polymerase chain reaction (PCR).  PCR - technique amplify the gene of interest.

Polymerase chain reaction is a method of amplifying a specific segment of DNA by making multiple copies of it, using primers and DNA polymerase

Kary Mullis invented the PCR technique in 1983 and was awarded the Nobel Prize in Chemistry in 1993 for this discovery.

PCR is an in vitro technique used to replicate specific DNA segments outside of a living organism.

PCR and RFLP (Restriction Fragment Length Polymorphism) are fundamental tools used in genetic engineering for DNA analysis, cloning, and mapping.

Southern hybridization involves DNA digestion, electrophoresis, blotting, and probe hybridization. PCR is a separate technique for amplification and is not a standard step in the Southern blotting procedure itself.

Simple sequence repeats (SSRs), sometimes described as genetic 'stutters,' are DNA tracts in which a short base-pair motif is repeated several to many times in tandem (e.g. CAGCAGCAG). These sequences experience frequent mutations that alter the number of repeats similar to Multigene Family, a set of genes descended by duplication and variation from some ancestral gene.

The primary function of PCR is the rapid amplification of specific DNA sequences.

PCR requires primers to define the target region and a DNA polymerase to extend the strands. DNA ligase is not used in PCR.

Taq polymerase is a thermostable DNA polymerase I obtained from the thermophilic bacterium Thermus aquaticus.

Taq polymerase is a thermostable DNA polymerase I obtained from the thermophilic bacterium Thermus aquaticus.

PCR is the standard method for amplifying specific DNA sequences using primers and thermal cycling.

The three steps of PCR are: 1) Denaturation (high heat to separate strands), 2) Annealing (cooling to allow primers to bind), and 3) Extension/Synthesis (optimal temperature for polymerase to build the new strand).

The DNA polymerase used in PCR (like Taq) is derived from thermophilic bacteria, making it heat-stable and capable of remaining active through the repeated high-temperature denaturation cycles.

DNA denaturation involves the separation of the two strands of the double helix. This process is driven by the breaking of hydrogen bonds between complementary nitrogenous bases.

PCR is a powerful technique for amplifying DNA sequences. Through repeated cycles of denaturation, annealing, and extension, a single DNA molecule can be amplified to approximately 1 billion copies.

In the PCR process, the denaturation step requires high temperatures to break the hydrogen bonds between DNA strands. This typically occurs between 90 and 95 degrees Celsius.

Taq polymerase is a thermostable DNA polymerase enzyme. It is isolated from the thermophilic bacterium Thermus aquaticus.

Taq polymerase is named after the bacterium Thermus aquaticus, which lives in hot springs and provides a heat-stable enzyme necessary for PCR.

PCR is an in vitro technique used to amplify specific DNA sequences. It utilizes a thermostable DNA polymerase to synthesize multiple copies of the target DNA.

PCR (Polymerase Chain Reaction) is the standard laboratory technique used to amplify specific segments of DNA.

Taq polymerase is the thermostable enzyme essential for the extension phase of the PCR reaction, allowing it to withstand high temperatures.

The primary purpose of the Polymerase Chain Reaction (PCR) is to create millions of copies of a specific DNA sequence, known as DNA amplification.

The number of DNA molecules after n cycles is calculated as N = N0 * 2^n. Here, N0 = 1000 and n = 20. So, N = 1000 * 2^20. Since 2^10 is approximately 10^3, 2^20 is approximately 10^6. Thus, 1000 * 10^6 = 10^9.

DNA polymerase is an enzyme that synthesizes DNA molecules from deoxyribonucleotides, the building blocks of DNA. The function of DNA polymerase is to replicate, proofread and repair DNA.DNA polymerases add nucleotide bases only when an RNA primer, a short piece of RNA, is already present. 

Polymerase Chain Reaction is a method widely used to make many copies of a specific DNA segment. Using PCR, a single (or more) copy of a DNA sequence is exponentially amplified to generate thousands to millions of more copies of that particular DNA segment. Components of PCR include DNA template, DNA polymerase, two DNA primers, nucleotides.

Polymerase Chain Reaction is a method widely used to make many copies of a specific DNA segment. Using PCR, a single (or more) copy of a DNA sequence is exponentially amplified to generate thousands to millions of more copies of that particular DNA segment.

PCR is the short form for polymerase chain reaction which is the phenomenon which is used for amplification of the part-specific region of DNA as per our interest. Taq polymerase is the enzyme that attaches nucleotides together and help is the extension of primer end on the template DNA.

In bacteria, transcription is performed by a single type of RNA polymerase that synthesizes all three types of RNA (mRNA, tRNA, and rRNA).

RNA polymerase I is responsible for transcribing rRNA (except 5S rRNA). RNA polymerase III transcribes tRNA, 5S rRNA, and snRNA. Option A is incorrect because RNA polymerase I does not transcribe snRNA or 5S rRNA.

Taq polymerase is a heat stable enzyme used in the polymerase chain reaction (PCR) to amplify segments of DNA in the lab. 

Majorly the PCR is used in analyzing and determining purposes only not the transferring purposes. For transferring purpose vectors are used. In analyzing and determining purposes, the sample is limited i.e. if the sample gets destroyed no analysis can be carried out which can be a big problem in the investigation cases. So to have extra copies of the sample it is first amplified by PCR.

A. Thermus aquaticus is a thermophilic bacteria which survives at high temperatures. Thus it's DNA polymerase is evolved to synthesize DNA at high temperature. This DNA polymerase is commercially available as "Taq polymerase" and is used in polymerase chain reaction (PCR).

For making numerous copies of a specific segment of DNA three steps are required

A)

Bioethics may be viewed as the set of standards that may be used to regulate various activities based on their effects on the biological world. This is because biotechnology has aroused social as well as political concerns, which have ranged from biotechnology being unnatural to detrimental to biodiversity.

Antioxidants prevent or slow down the oxidation of fat/oil which otherwise go rancid to emit a foul odor. This they are used as preservatives in oil or fat containing food.

Saffron is extracted from the dried stigmas of the saffron plant . It's main use is in the spice industry .While , the Beetroot is the taproot of the bet plant . It is widely used as in food and salads . Although these are also used as a medicine and a flavouring agent . 

• AGMARK is a certification mark employed on agricultural products in India. 
• Assuring that they conform to a set of standards approved by the Directorate of Marketing and Inspection. 
• All agricultural products like grain, milk, dairy product, etc. come under this quality assurance policy. 
• Ghee is a dairy product and it belongs to agriculture production so it should have AGMARK.
• So, the answer is option B.

• The sugarcane molasses are generally used as the fermentation medium. 
• The yeast cells are grown in this medium to perform anaerobic respiration which produces ethanol and carbon dioxide. 
• The molasses which are used is diluted so that the activity of yeast cells is fast and the production of ethanol occurs at a rapid pace. 
• If the process is slowed down, then the molasses must not have been diluted before the addition of the fermentation medium in the fermentor.
• Thus, the correct answer is option B. 

GMO stands for Genetically modified organisms. Any organism whose genetic material is modified by the use of genetic engineering technique is known as genetically modified organism. It is basically used to produce biotechnological products for the benefit of mankind.

Transposons are movable DNA sequences that can move (or jump) from one location in the genome to another and are found in bacteria. They leave a copy of themselves in the original position when they move to a new site. This phenomenon is significant  in antibiotic resistance. 

Genetically modified organisms are those whose genome is altered by transgene using the genetic engineering techniques to produce genetically modified foods. The genome of the modified organisms is altered by the gene of unrelated organisms. 

Bacillus thuringiensis (Bt) is a Gram-positive bacterium that produces crystals during sporulation. These crystals comprise ~130 kDa protoxins called crystal proteins which are potent and highly specific insecticides. Once ingested by specific host, these crystals dissolve in the alkaline conditions of the gut thereby activating the protoxins. The active toxins then bind to receptors on midgut epithelial cells, become inserted into the plasma membrane where they form pores leading to cell death through osmotic lysis. This special feature of Bt toxin was explored in genetic engineering to produce bioinsecticidal Bt brinjal plants. Correct answer is C.

Genetically modified crops can incorporate genes from various sources, including closely related species, distantly related species, bacteria, or animals, to introduce desired traits like pest resistance or drought tolerance.

• Maize hybrids with higher lysine content were developed to improve the protein in corn.
• This hybrid maize provides substantially higher levels of two essential amino acids - Lysine and tryptophan.
• So the correct answer is 'Lysine'

• Wheat is a  cereal grain which is a worldwide staple food. Wheat is an important source of carbohydrates and has a protein content of about 13%, which is relatively high compared to other major cereals.
• RR-21 (Sonalika) is a high yielding variety of wheat which is an early maturing single dwarf wheat with wide adaptation and good attractive amber grains. The variety is very suitable for late sowings. It is resistant to rusts.
• Other varieties of wheat are kalyansona and girija.

Golden rice is produced by genetic engineering to biosynthesize beta-carotene. Genetically modified corn is a genetically modified crop. Maize strains have been genetically engineered to acquired traits, including resistance to pests and to herbicides. Flavr Savr a genetically modified tomato was the first commercially grown genetically engineered food for human consumption.  Basmati rice GM crops have increased the reliance of farmers on herbicides and leading to new weed problems as well as to many legal problems.