UPSC – CSE Prelims 2023
S&T – BIOTECHNOLOGY
1. ‘‘Walachia method’ is sometimes talked about with reference to which one of the following?
(a) Controlling the viral diseases spread by mosquitoes
(b) Converting crop residues into packing material
(c) Producing biodegradable plastics
(d) Producing bio char from thermo- chemical conversion of biomass
Answer: (a) Controlling the viral diseases spread by mosquitoes
The “Walachia method” is a biological control method used to control the spread of viral diseases, such as dengue, Sika, and chikungunya, which are transmitted by mosquitoes. Walachia is a naturally occurring bacterium found in many insects, including mosquitoes. When male mosquitoes carrying Walachia are released and mate with wild female mosquitoes, the resulting eggs do not hatch or develop properly, reducing the mosquito population over time. This method has shown promising results in reducing the transmission of viral diseases by mosquitoes and has been implemented in various regions as a strategy for mosquito-borne disease control.
S&T – BIOTECHNOLOGY
2. ‘Aerial metagenomics’ best refers to which one of the following situations?
(a) Collecting DNA samples from air in a habitat at one go
(b) Understanding the genetic makeup of avian species of a habitat
(c) Using air-borne devices to collect blood samples from moving animals
(d) Sending drones to inaccessible areas to collect plant and animal samples from land surfaces and water bodies
Answer: (a)
The best interpretation of “aerial metagenomics” refers to option (A) – collecting DNA samples from the air in a habitat at one go. Aerial metagenomics involves the sampling and analysis of genetic material, such as DNA, found in the air. It aims to characterize and study the microbial communities present in the air, including bacteria, viruses, fungi, and other microorganisms. This technique allows scientists to study the biodiversity and genetic composition of airborne organisms without the need for direct sampling from individual organisms.
S&T – BIOTECHNOLOGY
3. ‘Microsatellite DNA’ is used in the case of which one of the following?
(a) Studying the evolutionary relationships among various species of fauna
(b) Stimulating ‘stem cells’ to transform into diverse functional tissues
(c) Promoting clonal propagation of horticultural plants
(d) Assessing the efficacy of drugs by conducting series of drug trials in a population
Answer: (a)
The term “Microsatellite DNA” (also known as “short tandem repeats” or “microsatellites”) is primarily used in the case of option (a) – studying the evolutionary relationships among various species of fauna. Microsatellites are short, repetitive sequences of DNA found in the genomes of many organisms, including animals, plants, and humans.
Microsatellite DNA is characterized by tandem repeats of short DNA sequences, typically 1-6 base pairs in length. These repeats can vary in the number of times they are repeated, creating genetic variation among individuals. By analyzing the variations in microsatellite regions across different species, scientists can study the evolutionary relationships, genetic diversity, and population structure of organisms.
Microsatellites are particularly useful in population genetics studies, where they can provide insights into gene flow, genetic drift, and relatedness among individuals or populations. They can be used to determine the genetic relatedness between different species or within a single species, assess population sizes and migration patterns, and investigate patterns of genetic adaptation and speciation.
While microsatellite DNA has various applications in genetic research, it is specifically associated with the study of evolutionary relationships and population genetics, making option (a) the correct choice in this case.