PCR is a useful tool for early diagnosis of an infectious disease. Elaborate.
PCR is a very sensitive technique which enables the amplification of desired DNA from a limited amount of DNA template.
Hence, it can detect the presence of an infectious organism in the infected patient at an early stage of infection (even before the infectious organism has multiplied to large number).
What is GEAC and what are its objectives?
GEAC (Genetic Engineering Approval Committee) is an Indian Government Organisation. Its objectives include
(i) Examine the validity of Genetic Modification (GM) of organism research.
(ii) Inspect the safety of introducing GMO for public services.
For which variety of Indian rice, the patent was filed by a USA company?
Indian Basmati rice was crossed with semi-dwarf variety and was claimed as a new variety for which the patent was field by a USA company.
Discuss the advantages of GM0.
Advantages of GMO are
(i) GMO food crops have shorter growing cycles, greater resistance to both insects and diseases, higher yields and higher nutritional value.
(ii) GMO animals have increased production and nutritive values, e.g., GM, cows may produce more milk.
(iii) The World Health Organisation or WHO, claims that GMO plants and animals may allow food prices to drop as food sources become more abundant.
Gene expression can be controlled with the help of RNA. Explain the method with an example.
RNAi technology is used to block the expression of certain genes and also referred to as gene silencing. During this process, a complementary RNA to the mRNA being produced by the gene is introduced into the cell. This RNA binds to the mRNA making it double stranded and therefore, stops the process of translation.
e.g., a nematode Meloidegyne incognitia infects the roots of tobacco plants which reduces the production of tobacco.
It can be prevented by using RNA interference (RNAi) process which is checked by silencing of specific mRNA due to a complementary dsRNA.
dsRNA binds and prevents the translation of mRNA (silencing). By using Agrobacterium vectors, Nematode-specific genes were introduced into the host plants which produces both sense and anti-sense RNA in the host cells.
These two RNAs are complementary to each other and form a double-stranded RNA (dsRNA) that initiates RNAi and hence, silence the specific mRNA of the nematode. The parasite cannot survive in transgenic host and so prevents the plants from pests.