Daily Current Affairs (MCQ) | Date 29.03.22

Daily Current Affairs (MCQ) | Date 29.03.22

Daily Current Affairs (MCQ) | Date 29.03.22

Q1. Consider the following statements

1. Corals are marine invertebrates
2. Hard corals extract calcium carbonate from the seawater to build hard, white coral exoskeletons
3. Coral reefs are the largest living structures on the planet

Which of the above statements is/are correct?

a. 1 and 2 only
b. 2 only
c. 1 and 3 only
d. 1, 2 and 3

Answer : d

Why is the Question ?

Great Barrier Reef
The management authority of the world’s largest coral reef system, Australia’s Great Barrier Reef, confirmed that the reef is experiencing a mass coral bleaching event.
1. This is the sixth time that the coral reef system is being hit by a widespread and damaging bleaching event and the fourth time in six years that such an event has occurred.
2. Australia’s Great Barrier Reef is the world’s largest reef system stretching across 2,300 km. It hosts 400 different types of coral, gives shelter to 1,500 species of fish and 4,000 types of mollusc.

What are coral reefs?
1. Corals are marine invertebrates or animals not possessing a spine. Each coral is called a polyp and thousands of such polyps live together to form a colony, which grows when polyps multiply to make copies of themselves.
2. Corals are of two types — hard coral and soft coral. Hard corals, also called hermatypic or ‘reef building’ corals extract calcium carbonate (also found in limestone) from the seawater to build hard, white coral exoskeletons.
3. Soft coral polyps, however, borrow their appearance from plants, attach themselves to such skeletons and older skeletons built by their ancestors.
4. Soft corals also add their own skeletons to the hard structure over the years and these growing multiplying structures gradually form coral reefs. They are the largest living structures on the planet.

Q2. Consider the following statements

1. Corals share a symbiotic relationship with single-celled algae called zooxanthellae
2. The algae provide the coral with food and nutrients and the corals give the algae a home and key nutrients 

3. The zooxanthellae also give corals their bright colour

Which of the above statements is/are correct?

Answer : d

Why is the Question ?

Corals share a symbiotic relationship with single-celled algae called zooxanthellae. The algae provide the coral with food and nutrients, which they make through photosynthesis, using the sun’s light. In turn, the corals give the algae a home and key nutrients. The zooxanthellae also give corals their bright colour.

Q3. Consider the following statements

1. Coral bleaching happens when corals experience stress in their environment due to changes in temperature, pollution or high levels of ocean acidity
2. Coral reefs support over 25% of marine biodiversity, including fish, turtles and lobsters; even as they only take up 1% of the seafloor
3. Great barrier reef is situated in Indian Ocean

Which of the above statements is/are correct?

a. 1 and 2 only
b. 2 only
c. 1 and 3 only
d. 1, 2 and 3

Answer : a

Why is the Question ?

What is coral bleaching?
1. Bleaching happens when corals experience stress in their environment due to changes in temperature, pollution or high levels of ocean acidity.
2. Under stressed conditions, the zooxanthellae or foodproducing algae living inside coral polyps start producing reactive oxygen species, which are not beneficial to the corals.
3. So, the corals expel the colour-giving zooxanthellae from their polyps, which exposes their pale white exoskeleton, giving the corals a bleached appearance. This also ends the symbiotic relationship that helps the corals to survive and grow.
4. Bleached corals can survive depending on the levels of bleaching and the recovery of sea temperatures to normal levels.
5. If heat-pollutions subside in time, over a few weeks, the zooxanthellae can come back to the corals and restart the partnership but severe bleaching and prolonged stress in the external environment can lead to coral death.

6. Over the last couple of decades, climate change and increased global warming owing to rising carbon emissions and other greenhouse gases have made seas warmer than usual.
7. Under all positive outlooks and projections in terms of cutting greenhouse gases, sea temperatures are predicted to increase by 1.5°C to 2°C by the time the century nears its end.
A 2021 study by the Global Coral Reef Monitoring Network (GCRMN), which is supported by the United Nations, showed that 14% of the world's coral on reefs had been lost between 2009 and 2018, with most of the loss attributed to coral bleaching.
Why does it matter?
1. Coral reefs support over 25% of marine biodiversity, including fish, turtles and lobsters; even as they only take up 1% of the seafloor. The marine life supported by reefs further fuels global fishing industries.
2. Even giant clams and whales depend on the reefs to live. Besides, coral reef systems generate $2.7 trillion in annual economic value through goods and service trade and tourism.
3. In Australia, the Barrier Reef, in pre-COVID times, generated $4.6 billion annually through tourism and employed over 60,000 people including divers and guides. Aside from adding economic value and being a support system for aquatic life, coral reefs also provide protection from storm waves.
4. Dead reefs can revive over time if there are enough fish species that can graze off the weeds that settle on dead corals, but it takes almost a decade for the reef to start setting up again. The reefs which were severely damaged in 1998 did recover over time.
What is the current condition of the Great Barrier Reef?
The United Nations Intergovernmental Panel on Climate Change (IPCC) released its report in March 2023, which warned that the life of the Great Barrier is in grave danger. The report said that if temperatures continue to rise, bleaching events may occur more often and a large proportion of the remaining reef cover in Australia could be lost.

Q4. Which of the following are sources of microplastics in the ocean?

1. Car tires
2. Synthetic textiles
3. Personal care products
4. City dust

Select the correct answer from the codes given below

a. 1, 2 and 3
b. 2, 3 and 4
c. 1, 2 and 4
d. 1, 2, 3 and 4

Answer : d

Why is the Question ?

Detecting microplastics in human blood

 Microplastics are, as the name suggests, tiny particles of plastics found in various places — the oceans, the environment, and now in human blood.
 A study has found plastic particles in human blood. About half of these were PET (polyethylene tetraphthalate) plastics, which is used to make food-grade bottles. The size of the particles that the group looked for was as small as about 700 nanometres (equal to 0.0007 millimetres).
 This is really small and it remains to be seen if there is a danger of such particles crossing the blood cell walls and affecting the organs. Also, a larger study needs to be conducted to firm up the present findings.
What are microplastics?
1. Microplastics are tiny bits of various types of plastic found in the environment. The name is used to differentiate them from “macroplastics” such as bottles and bags made of plastic.
2. Normally microplastics are defined as plastics particles less than 5mm in length.
3. The study looked at the most commonly used plastic polymers. These were polyethylene tetraphthalate (PET), polyethylene (used in making plastic carry bags), polymers of styrene (used in food packaging), poly (methyl methylacrylate) and poly propylene. They found a presence of the first four types.

What is the significance of the study?
Making a human health risk assessment in relation to plastic particles is not easy, perhaps not even possible, due to the lack of data on the exposure of people to plastics. In this sense, it is important to have studies like this one.
Does the presence of microplastics in blood have health impacts?
1. It is not yet clear if these microplastics can cross over from the bloodstream to deposit in organs and cause diseases.
2. Oral administration of microplastics in rats led to the accumulation of these in the liver, kidney and gut.

Q5. Which of the following countries are part of the Bay of Bengal Initiative for Multi-Sectoral Technical and Economic Cooperation (BIMSTEC) grouping?

1. Indonesia
2. Maldives
3. Srilanka
4. Thailand

Select the correct answer from the codes given below

a. 1 and 2 only
b. 3 and 4 only
c. 1, 2 and 4
d. 1, 2, 3 and 4

Answer : b

Why is the Question ?

BIMSTEC summit is likely to adopt a charter, the road map for connectivity
1. The Bay of Bengal Initiative for Multi-Sectoral Technical and Economic Cooperation (BIMSTEC) is set to adopt a charter and a roadmap for connectivity at the summit to be hosted by Sri Lanka, marking the continuing pivot away from SAARC.
2. The BIMSTEC charter, which will give greater cohesion to the group that includes Bangladesh, Bhutan, India, Myanmar, Nepal, Sri Lanka and Thailand, is expected to be signed during the summit, which will be held virtually.
3. The BIMSTEC master plan for transport connectivity is also expected to be adopted at the meet, people familiar with the matter said.
4. The summit is being held virtually because some member states, including India, were reluctant to share a platform with Myanmar’s junta, which has shown no signs of moving the country towards democracy.