Q4. Why is the plasmid called a vector?
It transfers the piece of DNA attached to it into the host organism, as a mosquito acts as an insect vector to transfer the malarial parasite into the human body (NCERT page 165).
Q5. Why is genetic engineering preferred to traditional hybridisation for adding a trait?
Traditional hybridisation very often brings in and multiplies undesirable genes along with the desired ones; genetic engineering isolates and introduces only one or a set of desirable genes (NCERT page 164). Beyond the NCERT text: it does not by itself rule out unintended effects, which still have to be assessed (our reading).
Q6. Give two processes, other than making products with microbes, that NCERT counts as part of biotechnology.
Any two of: in vitro fertilisation leading to a test-tube baby; synthesising a gene and using it; developing a DNA vaccine; correcting a defective gene (NCERT page 163).
Q7. In the NCERT account, in which host was the antibiotic resistance gene cloned, and which enzyme of the host copied it?
In Escherichia coli, a bacterium closely related to Salmonella; it replicated using the host’s DNA polymerase (NCERT page 165).
Q8. What does bioprocess engineering keep out, and why?
Microbial contamination: it maintains a sterile ambience so that only the desired microbe or eukaryotic cell grows, in large quantities, for products such as antibiotics, vaccines and enzymes (NCERT page 164).