question_answer

(i) While performing a cloning experiment on which basis you will select a vector.

(ii) State the reason behind the fact that DNA cannot pass through the cell membrane.

Or

(i) What is biotechnology? What are the future critical research areas in biotechnology?

(ii) Highlight five areas, where biotechnology has influenced our lives?

Answer:

(i) On the basis of following characters vector will be selected

(a) Origin of replication (ori) It is a specific DNA sequence from where the process of replication begins. Thus, any piece of DNA when linked to this sequence can be made to replicate within the host cells.

(b) Selectable marker It helps in identifying or selecting the transformants and eliminating non - transformants and hence, selectively permits only the growth of the transformants.

(c) Cloning sites These are generally required to link foreign or alien DNA with the vector. For this, the vector requires very few or single recognition sites for commonly used restriction enzymes, e.g. restriction sites in E. coli cloning vector include Hind III, Eco RI, Bam HI, Sal I, etc.

(ii) DNA is present in the nucleus and not in the cytoplasm of the cell just to protect it from various enzymes found in the cytoplasm. DNA is a hydrophilic molecule and cannot easily pass through the cell membrane, unlike hydrophobic molecules. Cell membranes are madeup of phospholipids and cholesterols making the DNA molecule impermeable.

Or

(i) Biotechnology is the integration of natural science and organisms, cell parts and molecular analogoues for products and services.

Three critical research areas of biotechnology are

(a) Providing the best catalyst in the form of improved organisms usually a microbe or pure enzyme.

(b) Creating optimal conditions through genetic engineering for a catalyst to act.

(c) Downstream processing technologies to purify the protein or organic compound.

(ii) Biotechnology has influenced our lives in the following ways

(a) It has provided us with genetically modified crops of better quality and high nutrient value.

(b) It has made available better and safer recombinant vaccines.

(c) It has also helped to develop transgenic animals that can produce human protein.

(d) It has enabled gene therapy for various genetic diseases.

(e) Environment pollution has also been taken care of with the help of genetically engineered microbes.