Important Questions for Class 12 Biology 11th Chapter Biotechnology: Principles and Processes MCQ, Very Short, Short Type, Long Type
CBSE Class 12 Important Questions for Class 12 Biology Chapter 11 Biotechnology: Principles and Processes all MCQ Type, Very Short Type, Assertion Reason Type, Case Study, Short Type and Long Type Questions with Answers by Expert. Important Questions for Section A, B, C, D Class 12 Biology Chapter 11.
MCQ
1.) The cutting of DNA at specific locations became possible with the Molecular scissors also called as
(a) DNA ligases
(b) Restriction enzymes
(c) Polymerase
(d) RNA synthase
(2) Assertion: When cut by the same restriction enzyme, the resultant DNA fragments have the same kind of ‘sticky-ends
Reason: These can be joined together (end-to-end) using DNA ligases
a.) Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.
b.) Both Assertion and Reason are correct and Reason is not the correct explanation for Assertion.
c.) If assertion is true but the reason is false.
d.) If both assertion and reason are false
(3) Fragments of DNA can be separated by
(a) Gel electrophoresis
(b) Western blotting
(c) ELISA
(d) PCR
(4) Assertion: bioreactors can be thought of as vessels in which raw materials are biologically converted into specific products, individual enzymes, etc. using microbial plant, animal or human cells
Reason: A bioreactor provides the optimal conditions for achieving the desired product by providing optimum growth conditions (temperature, pH, substrate, salts, vitamins, oxygen).
a.) Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.
b.) Both Assertion and Reason are correct and Reason is not the correct explanation for Assertion.
c.) If assertion is true but the reason is false.
d.) If both assertion and reason are false
(5) Molecules that are able to covalently bond to and carry foreign DNA into either plant or animal cells is
(a) Vector
(b) cDNA
(c) Recombinant protein
(d) mRNA
(6) In nature, restriction endonucleases in bacterial cells are used for__________
(a) Killing invading phage
(b) Plasmid replication
(c) Both a and b
(d) None of the above
(7) Assertion: Cloning is making multiple unidentical copies of any template DNA.
Reason: No Ori site are required for cloning
a.) Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.
b.) Both Assertion and Reason are correct and Reason is not the correct explanation for Assertion.
c.) If assertion is true but the reason is false.
d.) If both assertion and reason are false
(8) The separated DNA fragments can be visualized only after staining the DNAwith
(a) Ethidiumbromide
(b) Crystal violet
(c) Methyl blue
(d) All the above
(9) b-galactosidase gene when inactivated in blue white screening, the color produced will be
(a) Blue
(b) White
(c) Red
(d) None of above
(10) Cells can be made competent to receive foreign DNA by Treating it with
(a) Calcium ions
(b) Chlorine ions
(c) Fluorine ions
(d) Bromine ions
Answer in one sentence
(1) Enlist some processes/ techniques involved in biotechnology
Ans. Biotechnology includes in vitro fertilization, which results in a “test-tube” baby, synthesizing a gene and using it, producing a DNA vaccine, and repairing a damaged gene.
(2) Define: Biotechnology
Ans. 1.) Biotechnology is concerned with the use of live creatures or their enzymes to create goods and processes that are helpful to humans.
2.) According to The European Federation of Biotechnology (EFB) biotechnology is ‘The application of natural science to organisms, cells, and sections of organisms, as well as molecular equivalents for products and services.’
3.) Name 2 techniques that enabled birth of modern biotechnology
Ans. 2 techniques that enabled birth of modern biotechnology are
- Genetic engineering
- Bioprocess engineering
4.) What is origin of replication?
Ans. The origin of replication is a specific DNA sequence in a chromosome that is responsible for starting replication.
5.) How is DNA can be separated from other plant materials?
Ans. 1.) By using enzymes such as lysozyme (bacteria), cellulase (plant cells), and chitinase (animal tissue) to treat bacterial cells, plant cells, or animal tissue (fungus) the DNA can be separated from other plant materials.
2.) Treatment with ribonuclease can be used to remove RNA, while protease can be used to remove proteins.
6.) What is palindrome?
Ans. When the reading orientation is maintained the same, a palindrome in DNA is formed. The sequence of base pairs is reads the same on both strands.
Answer in short
Q.1) Explain the terms Genetic engineering and Bioprocess engineering
Ans. 1.) Genetic engineering is a set of techniques for altering the chemistry of genetic material (DNA and RNA) in order to introduce it into host organisms and change their phenotypic.
1.) Bioprocess engineering is the preservation of a sterile (microbial contamination-free) environment in chemical engineering processes to allow the growth of only the desired microbe/eukaryotic cell in large quantities for the production of biotechnological products such as antibiotics, vaccines, enzymes, and other biotechnological products.
Q.2.) State the steps involved in genetically modifying an organism
Ans. In genetically modifying an organism, there are three essential steps:
(i) selecting DNA with desirable genes
(ii) inserting the identified DNA into the hostand
(iii) retaining the introduced DNA in the host and propagating the DNA to its descendants.
Q.3.) How is DNA visualized after electrophoresis?
Ans. 1.) The separated DNA fragments can be seen only after dyeing the DNA with a chemical called ethidium bromide and then exposing it to UV rays.
2.) In an ethidium bromide-stained gel exposed to UV light, vivid orange-colored bands of DNA may be seen.
3.) The separated DNA bands on the agarose gel are cut out and removed from the gel component.
4.) This process is known as elution. The purified DNA fragments are then utilized to make recombinant DNA by combining them with cloning vectors.
Q.4) What is insertional inactivation?
Ans. 1.) Selection of recombinants owing to antibiotic inactivation is a time-consuming method that necessitates plating on two plates with different antibiotics at the same time.
2.) As a result, alternative selectable markers that distinguish recombinants from non-recombinants based on their ability to produce color in the presence of a chromogenic substrate have been devised.
3.) This involves inserting recombinant DNA into the coding sequence of the enzyme b-galactosidase.
4.) This causes insertional inactivation, which is the inactivation of the gene responsible for the synthesis of this enzyme.
5.) If the plasmid in the bacteria does not include an insert, the presence of a chromogenic substrate results in blue-colored colonies.
6.) The presence of an insert causes insertional inactivation of the b-galactosidase gene, and colonies that lack color are classified as recombinant colonies.
Q.5) How are the bacterial cells made competent to receive foreign DNA?
Ans. 1.) DNA cannot flow through cell membranes since it is a hydrophilic molecule.
2.) Bacterial cells must first be rendered ‘competent’ to take up DNA before they can be forced to take up the plasmid.
3.) This is accomplished by administering a precise concentration of a divalent cation, such as calcium, to the bacteria, which improves the efficiency with which DNA enters the bacterium through pores in the cell wall.
4.) Recombinant DNA can then be forced into such cells by incubating the cells with recombinant DNA on ice, then exposing them to 420C for a brief period of time (heat shock), and then returning them to ice.
5.) The bacteria can now take up the recombinant DNA.
Q.6) What is downstream processing?
Ans. 1.) After the biosynthetic stage is completed, the product must go through a series of processes before it can be sold as a finished product.
2.) Separation and purification are among the procedures, which are referred to as downstream processing.
3.) Preservatives must be included in the product’s formulation.
4.) As with pharmaceuticals, such formulations must go through extensive clinical testing.
5.) Each product must also undergo stringent quality control testing.
6.) From product to product, downstream processing and quality control tests differ.
Q.7) Short note on STIRRER TANK REACTOR.
Ans. 1.) To aid in the mixing of the reactor contents, stirred-tank reactors are usually cylindrical or have a curved base.
2.) The stirrer ensures that the bioreactor is evenly mixed and that oxygen is available throughout.
3.) Alternatively, the reactor can be bubbled with air.
4.) The bioreactor has an agitator system, an oxygen delivery system, and a foam control system, as well as a temperature control system, pH control system, and sampling ports for periodically withdrawing tiny amounts of the culture.
- Answer in brief
Q.1) Explain briefly Restriction enzymes
Ans. 1) Restriction enzymes are part of the nuclease family of enzymes. Exonucleases and endonucleases are the two types of restriction enzymes.
2) Endonucleases make cuts at specified places within the DNA, whereas exonucleases remove nucleotides off the ends.
3)The length of a DNA sequence is scanned by each restriction endonuclease.
4) It will connect to the DNA and cut each of the two strands of the double helix at precise spots in their sugar phosphate backbones after it has found its specific recognition sequence.
5) Each restriction endonuclease recognizes nucleotide sequences in DNA that are palindromic.
6) Restriction enzymes cut the DNA strand a little distant from the palindrome sites’ center, but between the identical two bases on both strands.
7) At the ends, single-stranded sections remain. Each strand has overhanging sections known as sticky ends.
8) Because they create hydrogen bonds with their corresponding cut counterparts, they are given this name. The work of the enzyme DNA ligase is aided by the stickiness of the ends.
9) In genetic engineering, restriction endonucleases are employed to create ‘recombinant’ DNA molecules, which are made up of DNA from different sources/genomes.
10) The resultant DNA fragments have the same kind of sticky-ends when cut by the same restriction enzyme, and they can be linked together (end-to-end) using DNA ligases.
Q.2) Which of the following are the characteristics that must be present in order for cloning into a vector
Ans. The following are the characteristics that must be present in order for cloning into a vector to be possible.
i) Replication origin (Ori): This is the sequence from which replication begins, and any portion of DNA can be forced to replicate within the host cells if it is linked to this sequence. This sequence is also in charge of regulating the quantity of copies of linked DNA.
ii) Selectable marker: The vector also requires a selectable marker, which aids in the identification and elimination of non-transformants while choosing allowing the growth of transformants. Antibiotic resistance genes, such as ampicillin, chloramphenicol, tetracycline, or kanamycin resistance genes, are usually considered valuable selection markers for E. coli. The regular E. coli cells aren’t resistant to any of these drugs.
iii) Cloning sites: In order to join the alien DNA, the vector must have a small number of, preferably single, restriction enzyme recognition sites. The presence of many recognition sites inside the vector will result in multiple fragments, making gene cloning more difficult. The ligation of alien DNA takes place at a restriction site in one of the two antibiotic resistance genes. For example, with the vector pBR322, you can ligate a foreign DNA at the BamH I site of the tetracycline resistance gene.
iv) Vectors for cloning genes in plants and animals: The tumour inducing (Ti) plasmid of Agrobacterium tumifaciens has been converted into a cloning vector that is no longer harmful to plants but can still deliver genes of interest into a range of plants using the processes. Retroviruses, however, have been de-armed and are now being utilized to transport desired genes into animal cells. So, after ligating a gene or a DNA fragment into an appropriate vector, it is delivered to a bacterial, plant, or animal host (where it multiplies).
Q.3) Describe in brief the process of gene amplification by PCR
Ans. 1.) PCR is the abbreviation of Polymerase chain reaction.
2.) Using two sets of primers (short chemically synthesized oligonucleotides that are complementary to the regions of DNA) and the enzyme DNA polymerase, multiple copies of the gene (or DNA) of interest are synthesized in vitro.
3.) Using nucleotides from the reaction and genomic DNA as a template, the enzyme expands the primers.
4.) If the process of DNA replication is done several times, a section of DNA can be amplified to a billion times, resulting in 1 billion copies.
5.) The use of a thermostable DNA polymerase (derived from the bacterium Thermus aquaticus) that remains active during the high temperature induced denaturation of double stranded DNA allows for recurrent amplification.
6.) If desired, the amplified region can now be ligated to a vector for further cloning.