UPSC Prelims 2020 - General Studies (Paper I)

Explanation

Figure: Carbon nanotubes Carbon nanotubes (CNTs) are cylindrical molecules that consist of rolled-up sheets of graphene (single-layer carbon atoms). These carbon nanotubes can be single-walled (SWCNT) or multi-walled (MWCNT) with a diameter of less than 1 nanometer (nm) or more than 100 nm, respectively. Multi-walled (MWCNT) nanotubes consist of several concentrically interlinked nanotubes. The length of nanotubes can reach up to several micrometers or even millimeters. These were earlier considered resistant to chemical damage and immune to biodegradation, but peroxidase enzymes were found to play an important role in the process of biodegradation of carbon nanotubes. The NASA has demonstrated the use of carbon nanotube arrays as biosensors. Carbon nanotubes (CNTs) are characterized by unique chemical and biological properties. These carbon nanotubes can penetrate through cell membranes, capillaries and accumulate in cells and tissues. This technology would facilitate the making of nanodevices using these blood-compatible nanomaterials as building blocks for biomedical applications such as artificial implants, including structural tissue replacements, that is, artificial blood vessels, or functional devices such as drug delivery matrixes. However using carbon nanotube as an artificial blood vessel, it can create blood clotting, and thus unsafe.

Explanation

The use of drones to spray pesticides (in Telangana) was in the news. It is considered illegal in India, but is legally practised in many of the states of the USA. Drones can be used to study the craters of active volcanoes a place which human beings cannot directly access. Australian scientists used drones to collect the mucus samples of whales from their water sprays to examine their health. Drone technology can be used in emergency disease control, weather forecasting etc.

Explanation

Earth Earth’s orbital path Spacecraft 2 Laser beams (1 incoming, 1 outgoing) Solar array Thrusters Gravity waves Spacecraft 1 Interferometers Spacecraft 3 Figure: Evolved Laser Interferometer Space Antenna (eLISA) project The LIGO detector found the second detection of gravitational waves in a research experiment on black holes using gravitational waves. The evolved Laser Interferometer Space Antenna (eLISA) project is a plan of setting three spacecraft, a mother and two daughter spacecraft into space. These spacecrafts will fly in a triangular formation and trail the earth in its orbit around the sun at a distance of over 50 million km. The distance of each arm of the imaginary triangle, from the mother to each daughter spacecraft will be about a million km. Freely falling test masses (cubes) with sides measuring about 46 mm will float inside these spacecraft, and laser interferometers will measure any changes by a gravitational wave in the distance between these cubes accurately.

Explanation

Germline gene therapy targets the reproductive cells, meaning any changes made to the DNA will be passed to the next generation. Germline gene therapy (its illegal) is when DNA is transferred into the cells that produce reproductive cells, eggs or sperm, in the body. Embryonic genetic editing is different from germline gene therapy and is possible to make genome changes to eliminate the vertical transfer of certain diseases and medical conditions. Animals bearing human cells and organs are human-animal chimeras. They offer insights into early human development and disease onset and provide a realistic drug-testing platform. Researchers, to see which cell-type would survive best, have experimented by injecting several different forms of human stem cells into pig embryos. The cells that survived longest and showed the most potential to continue to develop were intermediate human pluripotent stem cells.

Explanation

Conjugate vaccine combines a weak antigen with a strong antigen as a carrier so that the immune system has a stronger A Pneumococcal Conjugate Vaccine (PCV) gives prevention against pneumococcal diseases caused by bacteria called Streptococcus pneumoniae or pneumococcus. Pneumococcal infections can range from ear and sinus infections to pneumonia and bloodstream infection. It can prevent septicaemia (a kind of blood poisoning, also called sepsis) and meningitis. While vaccines are not intended to replace antibiotics, they can contribute to reduce AMR (Antimicrobial Resistance or drug resistance) by preventing (resistant) bacterial diseases. PCVs for pneumonia can potentially reduce the dependence on antibiotics by nearly 50% per year. Fever, loss of appetite, headache, fussiness are some side effects of Pneumococcal Conjugate Vaccines.