NCERT Questions for Class 12 Biology Chapter 9 – Biotechnology: Principles and Processes

Important Questions with Solutions of Class 12 Biology Chapter 9 – Biotechnology: Principles and Processes

1) Distinguish plasmid DNA and chromosomal DNA.

Ans – The common variations in plasmid DNA & chromosomal DNA are:

Plasmid DNA	Chromosomal DNA
The DNA is circular.	The DNA is linear in shape.
Discovered in prokaryotic cells i.e. bacterial cells.	Discovered in both prokaryotic cells and eukaryotic cells.
Works as a vector in rDNA technology.	Does not work as a vector in rDNA technology.

2) Define “Insertional Inactivation”.

Ans – The model where recombinant DNA is injected into the coding sequence of enzyme B resulting in galactosidase to the enzyme inactivation is called Insertional Inactivation. For example, we can hold the situation when the insert is unavailable in the bacteria plasmid leading to steps like insertional inactivation followed by the formation of colorless colonies in the place of blue-colored colonies due to the chromogenic substrate presence.

3) Modern Biotechnology pertains to 2 main techniques. State them.

Ans – The two main techniques involved in modern biotechnology are:

1. Genetic engineering- The technique where the genome is instigated and converted into another host organism or the basic trait of genetic material leading to the phenotype changing is alternated.
2. Massive microbes or cells are produced under sterile conditions using multiplication and growth methods.

4) In genetic engineering, what is the role of the enzyme “Ligase?”

Ans – The “Ligase” in genetic engineering can bind the two DNA elements together as a molecular Suture. It must be energized in the form of ATP to be joined efficiently while generating phosphodiester bonds between the 2 DNA cohesive endings.

5) Elaborate the use of gene Z as a marker.

Ans – The enzyme is inactivated as the DNA is recombinant in the coding sequence of an enzyme B-galactosidase due to the Lac Z Gene for the B-galactosidase coding. The blue-colored colonies (enter into the plasmid) created by the bacterial colony will result in the colorless production of colonies.

6) What are the significant properties of a good vector?

Ans – The significant properties of a good vector are:

1. Size – Assist in purification and isolation using size reduction techniques.
2. Origin of replication – Replication begins here and generates a sequence of base pairs. With the DNA attached, the replication occurs inside the host cells therefore controlling the number of copies linking DNA.
3. Selectable marker – A gene named selectable marker chooses the host cells containing vector & deleting the non-transformant. This helps in genetic engineering.
4. Cloning sites – The unique recognition site is inside the vector, attaching the foreign/alien DNA. The desired restriction enzyme will pass the vector only at specific recognition regions.

7) Agrobacterium-mediated genetic transformation is known as Natural Genetic engineering in plants. Elaborate.

Ans – With 2 genetic segments present on the bacterial TI-plasmid, the agrobacterium tumefaciens-interceded plant genetic transforms. The border sequence is the T-region which is encircled by T-DNA, imagining a conserved 25-base pair at its closure.

During infection, the tumor-inducing (TI) plasmid acts as a cloning vector transferring the needed gene into plants. For example: T.I. plasmid is used as a cloning vector for the plant. The vir (virulence) is the second region consisting of any event of seven important loci (virA, virB, virC, virD, and virE) and meditating the T-DNA processing and transfer i.e. Encoding the bacterial protein machinery regions.

With the hope of transformation into plant cells, T-DNA is attached to the gene of interest. Thus, agrobacterium-mediated genetic transformation is known as Natural Genetic engineering in plants.

8) State the equipment needed for genetic engineering.

Ans – The equipment and steps needed for genetic engineering are:

1. Restriction enzymes: As the fragments are formed, the restriction enzymes help in DNA strand digestion called molecular scissors. There are two pairs. They are Endonucleases and exonucleases.
2. Cloning vector: The attachment of the DNA segment in an organism as needed would transfer into some other organisms, cells, or DNA of them. It’s my right to behave compulsively.
3. Desired foreign DNA: Genes with different traits are part of the alien DNA and are transported into the genome of another cell with the hand of the cloning vector.

Conclusion

Biotechnology is the application of biological systems and organisms to develop new products and technologies. It involves the manipulation of living organisms or their components to create useful products, such as genetically modified crops or biopharmaceuticals. This interdisciplinary field combines biology, chemistry, physics, mathematics, and engineering to solve real-world problems and improve human well-being. The chapter of NCERT Chapter 9 is available in PDF format.