Science tech 2022 MCQs

Assess the age of a plant or animal:

• DNA Barcoding is not used to assess the age of plants or animals. It is primarily focused on identifying species through genetic sequences. The technique does not provide information about the age of an organism​​.

Distinguish among species that look alike:

• DNA Barcoding is highly effective in distinguishing among species that look alike. It uses short sequences of DNA to identify species, even those that are morphologically similar, making it a powerful tool for taxonomy and biodiversity research​​.

Identify undesirable animal or plant materials in processed foods:

• DNA Barcoding can indeed identify undesirable animal or plant materials in processed foods. By analyzing the genetic material found in food products, DNA Barcoding can detect the presence of species that are not listed on the product label or are not supposed to be there, ensuring food safety and compliance with labeling regulations​​.

Source: https://www.rgcb.res.in/dna.php

https://www.ibol.org/phase1/india-announces-10m-barcoding-initiative/

Other than those made by humans, nanoparticles do not exist in nature.

• This statement is incorrect. Nanoparticles do indeed exist in nature beyond human-made sources.
• Nature itself produces various nanomaterials, including inorganic ash, soot, sulfur, and mineral particles found in the air or wells.
• Additionally, bacteria and yeasts produce sulfur and selenium nanoparticles.
• These natural nanomaterials have diverse properties and applications in fields such as medicine, nutrition, cosmetics, and agriculture.

Nanoparticles of some metallic oxides are used in the manufacture of some cosmetics.

• This statement is correct. Nanoparticles of some metallic oxides are indeed used in the manufacture of cosmetics.
• These nanoparticles alter properties such as color, transparency, solubility, and chemical reactivity in cosmetic products.
• However, it is unclear to what extent insoluble nanoparticles are commonly used in cosmetics.

Nanoparticles of some commercial products which enter the environment are unsafe for humans.

• This statement is also correct. Nanoparticles from commercial products that enter the environment can indeed pose risks to human health.
• Research continues to focus on safety and regulatory considerations related to nanoparticles in cosmetics.

Source: https://dst.gov.in/scientific-programmes/mission-nano-science-and-technology-nano-mission

http://www.cense.iisc.ac.in/news/nanotechnology-india-current-status-and-future-prospects

• B cells and T cells are part of the immune system that helps protect the body from harmful substances such as pathogens and toxins.
• However, they are not specifically designed to protect against environmental allergens.
• Instead, the immune system sometimes mistakenly identifies harmless substances like pollen or dust mites as threats, leading to an allergic reaction.
• While B cells and T cells play a role in the body’s inflammatory response, they do not directly alleviate pain or inflammation.
• In fact, certain types of T cells can contribute to inflammation, which is a normal part of the body’s response to injury or infection. They are not typically involved in pain management.
• B cells and T cells are not immunosuppressants.
• They are key components of the immune system that help protect the body against infections.
• However, some specific subtypes of T cells, known as regulatory T cells, can suppress the immune response to prevent it from attacking the body’s own cells, thereby playing a role in preventing autoimmune diseases.
• B cells and T cells are crucial components of the immune system.
• B cells produce antibodies that can recognize and neutralize foreign substances (antigens), such as bacteria and viruses.
• T cells can directly kill infected cells or help other immune cells perform their functions.
• Together, they play a vital role in protecting the body from diseases caused by pathogens.

Source: https://cdsco.gov.in/opencms/opencms/en/biologicals

https://www.pib.gov.in/PressReleasePage.aspx?PRID=1725254

https://www.indiascienceandtechnology.gov.in/covid-19-vaccine/vaccine-introduction

They enable the digital representation of physical assets. -

• This statement is correct. NFTs can represent digital versions of physical assets. This makes it possible to buy, sell, and trade these assets in the digital world. For example, an artist can create a digital representation of their artwork and sell it as an NFT. This allows the artist to monetize their work in the digital space.

They are unique cryptographic tokens that exist on a blockchain. -

• This statement is correct. Each NFT is unique and cannot be replicated, which is why they are called ‘non-fungible’. They exist on a blockchain, which verifies their authenticity and ownership. This uniqueness is ensured by using blockchain technology such as Ethereum and smart contracts such as Binance Smart Chain which create a unique digital signature, thereby making them highly secure.

They can be traded or exchanged at equivalency and therefore can be used as a medium of commercial transactions. -

• This statement is incorrect. The key characteristic of NFTs is that they are non-fungible, meaning they are not interchangeable on a like-for-like basis because each one is unique. This differentiates them from cryptocurrencies like Bitcoin or Ethereum, which are fungible and can be traded at equivalency. However, NFTs have opened up new possibilities for commercial transactions in the digital space by enabling the tokenization of unique assets that are otherwise difficult to sell or hold ownership of.

Polyethylene terephthalate (PET) fibres can be blended with wool and cotton fibres to reinforce their properties.

• This statement is correct. PET is a synthetic fibre that can be blended with natural fibres such as cotton and wool to enhance their properties. The blending of PET with natural fibres results in fabrics that are strong, flexible, and resistant to wrinkles, shrinking, and tears.

Containers made of PET can be used to store any alcoholic beverage.

• This statement is incorrect. While PET containers are popular due to their ease of handling, safety, light weight, and superior barrier properties, they are not suitable for storing all types of alcoholic beverages³. Particularly for highly concentrated spirits in small PET bottles and high storage temperatures, the water permeation is unfavorable. The leaching effects of plastic and plastic chemical substances (such as ethylene glycol) have the tendency to leach considerably into alcohol stored if the temperature goes up during storage.

Bottles made of PET can be recycled into other products.

• This statement is correct. PET bottles can be recycled into a variety of products. The recycling process involves sorting, cleaning, decontaminating, and transforming the PET so that it can be reused. Recycled PET (rPET) can be used to make new bottles as well as many other products like winter jackets, rugs, playground equipment, dog beds, and more.

Articles made of PET can be easily disposed of by incineration without causing greenhouse gas emissions.

• This statement is incorrect. While incineration is a method of disposing of waste, it is not environmentally friendly when it comes to PET. The burning of plastics, including PET, releases toxic gases like dioxins, furans, mercury, and polychlorinated biphenyls (better known as BCPs) into the atmosphere. These emissions pose a threat to vegetation, and human and animal health.

Source: https://dst.gov.in/dst-supports-technologies-plastic-recycling

https://pib.gov.in/PressReleasePage.aspx?PRID=1842622

https://pib.gov.in/PressReleaseIframePage.aspx?PRID=1745433

GPS and navigation systems could fail:

• Solar storms can interfere with GPS signals, causing them to fail. This is because the solar storm’s charged particles can cause fluctuations in the Earth’s magnetic field, which can interfere with radio signals, including those used by GPS systems.

Tsunamis could occur at equatorial regions:

• Solar storms do not cause tsunamis. Tsunamis are caused by undersea earthquakes or other seismic activity. Solar storms and tsunamis are unrelated phenomena.

Power grids could be damaged:

• Solar storms can disrupt power grids and cause power outages. The charged particles from a solar storm can induce currents in power lines, which can overload the system and cause power outages.

Intense auroras could occur over much of the Earth:

• Solar storms can cause intense auroras, also known as the northern and southern lights. Auroras are caused by charged particles from the solar storm interacting with the Earth’s magnetic field and atmosphere.

Forest fires could take place over much of the planet:

• Solar storms do not cause forest fires. Forest fires are typically caused by human activity or natural phenomena like lightning. Solar storms and forest fires are unrelated phenomena.

Orbits of the satellites could be disturbed:

• Solar storms can affect satellites, including their orbits. The charged particles from a solar storm can cause drag on satellites, which can affect their orbits.

Shortwave radio communication of the aircraft flying over polar regions could be interrupted:

• Solar storms can disrupt radio communications, including shortwave radio communication of aircraft flying over polar regions. This is because the charged particles from a solar storm can cause fluctuations in the Earth’s magnetic field, which can interfere with radio signals.

Source: https://www.thehindubusinessline.com/blexplainer/all-about-solar-storms-and-how-they-affects-us/article65245445.ece

https://www.indiatoday.in/science/story/solar-flare-geomagnetic-storm-sun-space-weather-nasa-1827104-2021-07-12

Probiotics are made of both bacteria and yeast:

• This statement is correct. Probiotics are live microorganisms that are intended to have health benefits when consumed or applied to the body. They can be found in yogurt and other fermented foods, dietary supplements, and beauty products. Probiotics are live bacteria and yeasts that are thought to be beneficial in preventing several health conditions.

The organisms in probiotics are found in foods we ingest but they do not naturally occur in our gut:

• This statement is incorrect. Probiotics live naturally in your body. L. acidophilus is a probiotic bacteria that naturally occur in the human gut. The most common place linked to beneficial microbes in your gut (mostly large intestines), but there are other places like the mouth, urinary tract, skin, lungs, etc where these probiotics are found.

Probiotics help in the digestion of milk sugars:

• This statement is correct. Certain strains of bacteria in yogurt have ß-D-galactosidase, which is an enzyme that helps break down lactose in dairy products into the sugars glucose and galactose. Thus Probiotics help in the digestion of milk sugars.

Source: https://www.livescience.com/what-are-probiotics-and-how-do-they-work

Biofilms can form on medical implants within human tissues:

• This statement is correct. Biofilms are a complex group of microbial cells that can adhere to the exopolysaccharide matrices available on the surface of various medical devices, such as intravascular catheters, urinary catheters, dental implants, breast implants, and orthopedic implants. They are responsible for the failure of devices such as catheters and ventilator.

Biofilms can form on food and food processing surfaces:

• This statement is correct. Biofilms can form on food and food processing surfaces. They affect product quality and safety of food, and bacterial adhesion onto surfaces of processing equipment in contact with foods is indicated by the formation of biofilms.

Biofilms can exhibit antibiotic resistance:

• This statement is correct. Bacteria living in a biofilm can exhibit a 10 to 1,000-fold increase in antibiotic resistance compared to similar bacteria living in a planktonic state. Many times bacteria form biofilms to resist the action of antibiotics.

Source: https://vigyanprasar.gov.in/isw/seaweed-silver-combo-can-fight-drug-resistant-bacteria-biofilms.html

https://pharmaceuticals.gov.in/nipers