BIOLOGY M.C.Q [1M]

1. Fermentation tank

Explanation:

The bioreactor is a fermentation tank that allows microorganisms to ferment the media and undergo growth. Bioreactors are considered as vessels in which raw materials are biologically converted into specific products by microbes, plant and animal cells, or their enzymes.

4. Ethidium bromide stained DNA can be seen under exposure to UV light.

The separated DNA fragments can he visualised only after staining the DNA with a compound known as ethidium bromide followed by exposure to ultraviolet radiation (we cannot see pure DNA fragments in the visible light and without staining).

3. Identify recombinants from non recombinants

Explanation:

Due to the presence of the selective marker, the plasmid becomes useful for the cell. Under the selective conditions, only cells that contain plasmids with the appropriate selectable marker can survive. Thus it helps in identifying the recombinants from non-recombinants.

4. All of the above

Explanation:

Restriction endonucleases have been helpful to cut DNA at specific size and join our DNA of interest to get a recombinant DNA. Also the structure of DNA revolutionized the whole knoeldge about biotechnology.

4. Gold or tungsten

Explanation:

For gene transfer into the host cell without using vector microparticles made of tungsten and gold coated with foreign DNA are bombarded into target cells at a very high velocity. This method is called biolistics or gene gun which is suitable for plants.

1. Multiple gene family.

Explanation:

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.

4. Precipitate DNA

Explanation:

It is well known that Ethanol has a lower dielectric constant than water, making it promote ionic bond formations the Na+ (from the salt) and the PO3− (from the DNA backbone), further, causing the DNA to precipitate.

1. PCR

Explanation:

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.

4. Ethidium bromide can be used to visualize the DNA.

1. Origin of replication.

1. Extension of primer end on the template DNA.

1. Fragment of DNA which acts as vector.

3. Nucleases

4. Payen and Persoz

Explanation:

Diastase was the very first enzyme discovered by Jean-Francois Persoz and Anselme Payen in 1833. Diastase is an enzyme which helps to break carbohydrates into the simple sugar, which makes them easier to digest.

1. Protein synthesis

2. Restriction endonucleases and ligases

Explanation:

Recombinant DNA technology is the method of joining two or more DNA molecules to create a hybrid. This technology is made possible by two types of enzymes, restriction endonucleases and ligase. A restriction endonuclease recognizes a specific sequence of DNA and cuts within, or close to, that sequence. DNA fragments generated by digestion with a restriction endonuclease can be joined together again by the enzyme ligase.

3. Bioreactors

Explanation:

Bioreactors are considered as vessels in which raw materials are biologically converted into specific products by microbes, plant and animal cells or their enzymes. To produce large quantities of these products, bioreactors are used where large volumes (100-1000 litres) of culture can be processed. Bioreactor provides the optimal conditions for obtaining the desired product by providing optimum growth conditions such as temperature, pH, substrate, vitamins, oxygen and salts.

3. Insect pest.

3. Down stream processing

Explanation:

Downstream Processing is the recovery and purification of biochemical products with proper treatment. It is a series of events which includes cell separation, filtration, product recovery, extraction of product and purification and then treatment of product by chemical, physical and biological means.

3. Deoxyribonuclease.

Lysozyme is used for breaking the membranes which surround DNAs. Ribonuclease is used for removing RNA. Protease is used for removing protein. All these steps are necessary for isolation of DNA from bacteria.

2. Phosphodiester bond

Explanation:

Restriction enzymes are the endonucleases which cleave the DNA at  specific sites. These enzymes act on the phosphodiester bond which attaches  two nucleotides in the polynucleotide chain. There are specific restriction sites at which the enzymes make blunt or staggered cuts to produce the fragments of the DNA.

4. Conversion of a laboratory scale plant to manufacturing unit

Explanation:

Scaling up is the process of expanding a process from small scale to a larger scale. So, here scaling up is defined as the conversion of a laboratory scale plant into a manufacturing unit.

3. Origin of replication (ori).

3. Production of CO₂.

2. Exonuclease.

Exonucleases remove nucleotides from the ends of the DNA whereas endonucleases make cuts at specific positions within the DNA.

3. 1.0 billion

Explanation:

The 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. The number of double-stranded DNA pieces is doubled in each cycle so that after n cycles we have 2^n (2 to the n: the power) copies of DNA. The cycle is usually repeated 30 times and 1 billion copies are made at the end of 30 PCR cycles.

4. 5'-GAATTC-3' 3'-CTTAAG-5'

2. Recombinant DNA techniques.

1. Availability of Oxygen throughout the process

Explanation:

Stirred tank bioreactor is a reactor that consists of the propeller, the mixer and the reactor. In this system, impeller or mixer is used to mix the required atmospheric oxygen into the aqueous phase and maximizing the interfacial area between the gaseous and aqueous phases for large production of biomass.

3. Klebsiella pneumonia

Explanation:

Solution: The first nif gene for nitrogen fixation was isolated from Klebsiella pneumonia.

3. Both A and B

Explanation:

Restriction systems identify the origin of incoming DNA and destroy it 

if recognized as foreign. Restriction endonucleases recognize specific 

sequences in the incoming DNA and digest the DNA into fragments. They 

cut the DNA either at specific sites or more randomly. Hence, 

restriction endonucleases are synthesized by bacteria as part of their defense mechanism. These enzymes are used in genetic engineering to cut the gene of the interest from source DNA and to introduce them into the vectors; but this is not a natural function of restriction endonucleases. Transcription is the process of synthesis of RNA using the DNA template. RNA polymerase perform this function by adding ribonucleotides to the RNA primer. Translation of nucleotide sequence of mRNA into amino acid sequence of protein is called as protein synthesis. It is performed by tRNA. Restriction enzymes do not play any role in these two processes.

4. Milstein and Kohier, 1975

Explanation:

Hybridoma technology is a technology of forming hybrid cell lines (called hybridomas).

1. Six base pairs.

4. All of the above.

The differential mobility of DNA depends upon charge and size of DNA.

3. Human gene may have intron which bacteria cannot process.

1. Restriction endonucleases

Explanation:

Restriction endonucleases cut DNA segments at specific sites of 4 or 6 base pair length, called the restriction sites and are therefore known as the molecular scissors. DNA polymerase helps in the synthesis of DNA and RNA polymerase catalyses the synthesis of RNA. DNA ligases on the other hand help in joining DNA fragments by helping in the formation of phosphodiester bonds between them.

2. Polymerase chain reaction

Explanation:

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.

3. RNA-DNA

Explanation:

C. RNA-DNA
Solution : In retroviruses they can synthesize the DNA from RNA template in the host by help of reverse transcriptase that is RNA dependent DNA polymerase.

So the correct answer is " RNA-DNA"

2. Endonucleases

Explanation:

"Endonucleases" Endonucleases or restriction enzymes is an enzyme which result in a series of advancements in techniques that allowed the direct modification of the genome. Other advancements include the discovery of DNA ligases, the ability to design plasmids and technologies like polymerase chain reaction and sequencing.

1. Endonuclease

Explanation:

Any enzyme that can break the phosphodiester bond within the polynucleotide chain is called as endonuclease whereas exonuclease cleaves the phosphodiester bond from the end of the polynucleotide chain, arylsulphatase enzyme breaks the sulphatide during the hydrolysis of phenol and phosphotriesterase enzyme converts aryl dialkyl phosphate to dialkyl phosphate and aryl alcohol. 

3. Chitinase

3. DNA spooling

Explanation:

The purified DNA, after treatment with various enzymes, precipitates out after addition of chilled ethanol. This is viewed as a collection of fine threads in the suspension, and is easily collected. The process is known as DNA spooling.

3. Endonuclease

Explanation:

Endonucleases are the enzymes which cleave the phosphodiester bonds in the internal regions of the polynucleotide chain (DNA or RNA). The exonucleases cleave the polynucleotide chains from one end. While the protease cleaves the proteins the lipases act on the lipids.

1. Reporter

3. Nematodes.

1. Introducing rDNA into plant cells.

3. It is circular DNA which have capacity to join to eukaryotic DNA.

1. Cellulase and pectinase

Explanation:

Plant cells are surrounded with a cellulosic cell wall. Between adjacent plant cells is present middle lamella. The middle lamella is made up of calcium and pectin. Hence, plant cells of a tissue are separated from each other with the help of cellulase and pectinase enzymes. These enzymes are commercially used in clearing of fruit juices to dissolve plant fibres.

2. 90^o - 95^oC

Explanation:

Denaturation: The reaction temperature is increased to 95 degree centigrade, which melts (disrupts the hydrogen bond between complementary bases) all dsDNA into single-stranded DNA (ssDNA).