Ans: A

Exp:

Recently,  ICAR-Central Marine Fisheries Research Institute (CMFRI) has found that coral reefs in the Lakshadweep Sea have undergone severe bleaching due to prolonged marine heatwaves

Statement 1 is correct: Reef-building corals cannot tolerate water temperatures below 18° Celsius. 

• Many grow optimally in water temperatures between 23°–29°Celsius, but some can tolerate temperatures as high as 40° Celsius for short periods. 
• Most reef-building corals also require very saline water ranging from 32 to 42 parts per thousand.

Statement 2 is incorrect: Most reef-building corals contain photosynthetic algae, called zooxanthellae, that live in their tissues. The coral provides the algae with a protected environment and compounds they need for photosynthesis. 

• In return, the algae produce oxygen and help the coral to remove wastes. Most importantly, zooxanthellae supply the coral with glucose, glycerol, and amino acids, which are the products of photosynthesis. 
• The coral uses these products to make proteins, fats, and carbohydrates, and produce calcium carbonate.

Statement 3 is incorrect: Corals thrive in tropical oceans confined between 25 degree North and 25 degree South latitudes.  Corals are found mainly in the tropical oceans and seas because they require high mean annual temperature above 20 degree celsius.

• The coral is a polyp, an organism that lives in the shallow sea. Its skeleton is composed of limestone and dolomite. The layers of deposition of the skeletons of these polyps form a shallow rock known as Coral Reef.

Ans: B

Exp:

Recently, GE Healthcare unveiled head-only MRI scanner for advanced neuroscience research.

Statement 1 is correct: The strong magnetic field created by the MRI scanner causes the atoms in your body to align in the same direction. Radio waves are then sent from the MRI machine and move these atoms out of the original position.

• Magnetic resonance imaging (MRI) is used to obtain images of soft tissues within the body. Soft tissue is any tissue that hasn’t become harder through calcification. It is a non-invasive diagnostic procedure widely used to image the brain, the cardiovascular system, the spinal cord and joints, various muscles, the liver, arteries, etc.

Statement 2 is incorrect:An MRI procedure reveals an image of a body part using the hydrogen atoms in that part. A hydrogen atom is simply one proton with one electron around it. These atoms are all spinning, with axes pointing in random directions. 

•  Hydrogen atoms are abundant in fat and water, which are present almost throughout the body.At the center of each hydrogen atom is an even smaller particle called a proton. 
• Protons are like tiny magnets and are very sensitive to magnetic fields. When one lies under the powerful scanner magnets, the protons in the body line up in the same direction, in the same way that a magnet can pull the needle of a compass.

Statement 3 is correct: MRI  generates information (images of the body) using the intensity of radiation (the quantity of re-emitted photons) arriving from various parts of the body. 

• Protons in dense or solid structures tend to be more or less prone to misalignment when the disrupting radio waves are applied to the body’s tissue, resulting in a lower number of re-emitted photons coming from that region and thus a darker area in the resulting image.

Ans: C

Exp: 

Recently, the Delhi High Court has ordered State authorities to take action against the spurious use of oxytocin on cattle in dairy colonies in the Capital.

Statement 1 is correct: Oxytocin is a neuropeptide hormone produced in the hypothalamus of the brain and released by the pituitary gland. Often referred to as the “love hormone” or “bonding hormone” due to its role in social bonding, trust, and intimacy.

Statement 2 is correct: Administering oxytocin is deemed animal cruelty. The Delhi High Court has called for action against the spurious use of oxytocin in dairy colonies, citing it as animal cruelty.

• Animal cruelty is a cognizable offense under Section 12 of the Prevention of Cruelty to Animals Act, 1960. The Delhi High Court directed the Department of Drugs Control, GNCTD, to conduct weekly inspections. Cases of spurious oxytocin usage or possession must be registered under Section 12 of the Prevention of Cruelty to Animals Act, 1960, and Section 18(a) of the Drugs and Cosmetics Act, 1940.

Ans: B

Exp:

Recently, U.S. State Department accused Russia on May 1 of having used a chemical weapon Chloropicrin against Ukrainian forces 

About Chloropicrin:

• Chloropicrin is a chemical compound used broadly as a fungicide, herbicide, insecticide, nematicide and antimicrobial. 
• In appearance, it is a colorless yellow oily liquid.
• It’s manufactured today in a chemical reaction involving sodium hypochlorite (which in dilute form is called bleach) and nitromethane (a common industrial solvent). 
  • It can also be made by combining chloroform with nitric acid, which yields chloropicrin and water.
• It was first made for us as a poison gas in the First World War, by both the Allied and the Central Powers. 
• Chloropicrin has documented irritating and tears-inducing effects on humans, and is also known to be highly toxic and carcinogenic.

Ans: C

Exp:

Context: Farmers around the world are increasingly adopting the less intensive agricultural practices to improve soil health, raise yields, and trap carbon in the atmosphere back down in the soil.

• Option C is correct: Carbon farming refers to practices that aim to remove carbon dioxide (CO2) from the atmosphere and store it in natural systems such as forests, soils, and wetlands. 
• Some examples of carbon farming practices include afforestation, reforestation, conservation agriculture, and blue carbon sequestration. 
• Carbon farming strategically augments the natural carbon sinks which are forests, wetlands, soils and crops and not synthetic materials and storage tanks.