Answer: C

Explanation:

Glucagon: Glucagon is a hormone that regulates blood glucose levels by promoting the breakdown of glycogen in the liver. It does not have any effect on blood calcium and phosphate levels.

Growth Hormone: Growth hormone stimulates growth and cell reproduction in humans and other animals. It does not regulate blood calcium and phosphate levels.

Parathyroid hormone: Parathyroid hormone (PTH) is a hormone produced by the parathyroid glands that regulates blood calcium and phosphate levels. It increases blood calcium levels by promoting the release of calcium from bones and decreasing calcium excretion in the kidneys. It also increases phosphate excretion in the kidneys.

Thyroxine: Thyroxine is a hormone produced by the thyroid gland that regulates metabolism. It does not have any effect on blood calcium and phosphate levels. Hence, option (c) is the correct answer.

Answer: C

Explanation:

Scientists have genetically engineered some plants to be more drought-tolerant, which could be useful in areas with limited water resources. Hence, statement 1 is correct.

Genetic engineering has been used to increase the levels of vitamins and minerals in some crops, such as golden rice, which is engineered to produce more beta-carotene. Hence, statement 2 is correct.

While it is possible that genetically engineered plants could be used in space agriculture, this is not a current prospect for which they have been created. Hence, statement 3 is incorrect.

Genetic engineering has been used to create crops with longer shelf lives, such as tomatoes that ripen more slowly and stay fresh for longer. Hence, statement 4 is correct.

Answer: C

Explanation:

Wavelength is the distance between two adjacent peaks or troughs of a wave, and is measured in units of length, such as meters or nanometers. Frequency is the number of waves that pass a given point per unit time, and is measured in units of hertz (Hz), which represents one cycle per second. Hence, option (c) is the correct answer.

Answer: A

Explanation:

Crypto-currencies have made their way across the globe with the creation of Bit-coin in the year 2008. The gains in the sector since the beginning of the COVID-19 pandemic in January 2020 have been astonishing. It is known that the "crypto-market" increased by more than 500%. Recently the government has announced the introduction of the “Crypto-currencies and Official Digital Currencies Regulation Bill, 2021” to create a sovereign digital currency and also ban all private crypto-currencies.

Crypto-currencies work on the block-chain system i.e. peer-to-peer network, it helps prevent corruption by tracking the flow of funds and transactions. It can help in saving considerable time for the sender and receiver of funds as it operates completely over the internet. However, in the 2018-19 budget speech the Finance Minister pointed out that crypto-currencies are not recognized by the government. Hence, option (a) is correct.

Answer: A

Explanation:

New research in Zebrafish (Danio rerio) has demonstrated how 'induced hibernation' (torpor) can protect humans from space elements, especially radiation, during space flight. The researchers exposed Zebrafish to radiation to see what they would experience on a six-month trip to Mars. They observed signs of oxidative stress (an imbalance between antioxidants and free radicals), DNA damage, 'stress hormone signaling' and changes in the cell-division cycle. The researchers then induced 'torpor' in another group of Zebrafish that were exposed to the same amount of radiation. The results showed that torpor reduced the metabolic rate within the Zebrafish and created a 'radioprotective' effect, protecting against the harmful effects of radiation. Hence, option (a) is correct.