This Page Score: 0/40
Assertion (A):
Downstream processing is a crucial step that follows the biosynthetic stage in biotechnology.
Reason (R):
Downstream processing includes separation, purification, formulation with preservatives, clinical trials, and strict quality control testing of the product.
[Biotechnology-Principles-and-Processes] [class-xii ]
Assertion (A):
To isolate pure DNA for cutting by restriction enzymes, animal cells must be treated with enzymes like lysozyme and chitinase.
Reason (R):
Enzymes are required because the DNA is contained within cell membranes and needs to be released from other macromolecules like RNA and proteins.
[Biotechnology-Principles-and-Processes] [class-xii ]
Assertion (A):
Restriction enzymes cut DNA strands in a particular fashion, which leaves single-stranded ‘sticky ends’ on the strands.
Reason (R):
These clipped ends make pasting together pieces of DNA from different sources a precise exercise.
[Biotechnology-Principles-and-Processes] [class-xii ]
Assertion (A):
Plasmid DNA acts as a vector to transfer an alien piece of DNA into the host organism.
Reason (R):
Plasmids are naturally occurring autonomously replicating circular extra-chromosomal DNA found in bacterial cells.
[Biotechnology-Principles-and-Processes] [class-xii ]
Assertion (A):
The first step in genetically modifying an organism is the identification of DNA with desirable genes.
Reason (R):
The major utility of the biological world, historically, has been only as a source of food.
[Biotechnology-Principles-and-Processes] [class-xii ]
Assertion (A):
Genetic engineering techniques are necessary to overcome the limitations of traditional hybridisation procedures.
Reason (R):
Traditional hybridisation often leads to the inclusion and multiplication of undesirable genes along with the desired genes, which genetic engineering prevents.
[Biotechnology-Principles-and-Processes] [class-xii ]
Assertion (A):
The Roman number following the name of a restriction enzyme, such as $EcoRI$, indicates the order in which the enzyme was isolated from that strain of bacteria.
Reason (R):
The letter 'R' in the name $EcoRI$ is derived from the genus of the prokaryotic cell from which it was isolated.
[Biotechnology-Principles-and-Processes] [class-xii ]
Assertion (A):
Genes encoding resistance to antibiotics such as ampicillin or tetracycline are useful selectable markers for E. coli because normal E. coli cells naturally carry resistance against these antibiotics.
Reason (R):
A selectable marker helps in identifying and eliminating non-transformants while permitting the selective growth of the transformants.
[Biotechnology-Principles-and-Processes] [class-xii ]
Assertion (A):
Cloning vectors must have very few, preferably single, recognition sites for commonly used restriction enzymes.
Reason (R):
The presence of multiple recognition sites within the vector will generate several fragments, which will complicate the gene cloning procedure.
[Biotechnology-Principles-and-Processes] [class-xii ]
Assertion (A):
In insertional inactivation, colonies of non-recombinants carrying the intact $eta$-galactosidase gene appear white in the presence of a chromogenic substrate.
Reason (R):
The intact $eta$-galactosidase gene results in enzyme synthesis which converts the chromogenic substrate into a blue product.
[Biotechnology-Principles-and-Processes] [class-xii ]
This Page Score: 0/40