IAS Prelims GS Questions and Answers - Apr 21, 2016

ANSWER: 2, 3

Explanation:
The salient features of the Paris Agreement are as follows:

• The Paris Agreement acknowledges the development imperatives of developing countries. The Agreement recognizes the developing countries' right to development and their efforts to harmonize development with environment, while protecting the interests of the most vulnerable.
• The Paris Agreement recognizes the importance of sustainable lifestyles and sustainable patterns of consumption with developed countries taking the lead, and notes the importance of 'climate justice’ in its preamble.
• The Agreement seeks to enhance the 'implementation of the Convention' whilst reflecting the principles of equity and common but differentiated responsibilities and respective capabilities, in the light of different national circumstances.
• The objective of the Agreement further ensures that it is not mitigation-centric and includes other important elements such as adaptation, loss and damage, finance, technology, capacity building and transparency of action and support
• Pre-2020 actions are also part of the decisions. The developed country parties are urged to scale up their level of financial support with a complete road map to achieve the goal of jointly providing US $ 100 billion by 2020 for mitigation and adaptation by significantly increasing adaptation finance from current levels and to further provide appropriate technology and capacity building support.

ANSWER: Only 1

Explanation:

• Trees share carbon among themselves. This is concentrated in the root zone.
• There is no bar of species for it.
• In fact, the roots of neighbouring trees, species no bar, shared an almost similar carbon isotopic signature.
• The scientists strongly suspect that this interaction is mediated by networks of symbiotic fungi called mycorrhiza which connect the roots of different trees.
• Mycorrhizal networks are very common in most forests across biomes and climates. In spruce forests they are so common that they are considered a substantial carbon sink.

ANSWER: All of the above

Explanation:

• The monsoon is mainly driven by thermal contrast between the Indian subcontinent and the adjoining ocean.The South Asian Monsoon has been weakening since the 1950s with an increased incidence of extreme rainfall events.
• It is attributed to increased greenhouse gas (GHG) emissions, atmospheric aerosols and land-use changes.
• Land use changes includes deforestation.
• The reduction in land-sea temperature contrast is also attributed mostly to a strong warming in the Indian Ocean. This is due to global warming.
• Greenhouse gases trap the heat over land and sea and result in both the land and sea being warm, that is the thermal contrast is greatly reduced. This leads to a weakening of the monsoon circulation and the result is a weakened monsoon.
• However, a warmed up atmosphere can hold more moisture and this situation can result in heavy rainfall over some regions.

ANSWER: They reduce incoming solar radiation

Explanation:

• Anthropogenic atmospheric aerosols, including sulphates, black carbon, nitrates and dust accumulate over the Indo-gangetic plains. These reduce incoming solar radiation over northern India and the northern Indian Ocean and lead to cooling on both land and sea resulting in a lowered thermal contrast.
• Hence, monsoon winds and circulation are weakened as both land and sea are cooled. Evaporation is also suppressed. Over South Asia, over 50 per cent of aerosol emissions are caused by biomass and agricultural burning. There is mounting evidence of the emissions from South Asia and China in changing the timing, spatial distribution and strength of the monsoon.
• However, negative impacts of these aerosols can be reduced quickly as they have a short lifetime of few weeks compared to GHGs which can stay in the atmosphere for up to 80 years.

ANSWER: Increases albedo effect of land over ocean

Explanation:

• An important contributor to monsoon weakening is the albedo effect of deforestation by humans.
• Reduced land cover increases the reflectivity (albedo effect) which leads to cooling of land in contrast to the ocean and results in a weakened monsoon circulation.

ANSWER: Convective processes

Explanation:

• The surface warming in the Indian Ocean, especially in the western regions has reached values of up to 1.2 degrees C during the past century, much larger than the warming trends in other tropical oceans. The decrease in the land-sea thermal contrast surface temperature trends (1901-2012) is also visible in the upper atmosphere, as the warming trends in the ocean surface are transferred to the atmosphere above through convective processes.
• Convective heat transfer, often referred to simply as convection, is the transfer of heat from one place to another by the movement of fluids. Convection is usually the dominant form of heat transfer (convection) in liquids and gases.
• The warm air rises up and its place is taken by the cool air.

ANSWER: Only 2

Explanation:

• An anticyclone (that is, opposite to a cyclone) is a weather phenomenon that is a large-scale circulation of winds around a central region of high atmospheric pressure.
• It moves clockwise in the Northern Hemisphere, anti-clockwise in the Southern Hemisphere.
• The strongest anticyclones occur over snow-covered portions of Asia and North America in the winter when clear, dry air masses cool from a loss of infrared radiation, while little sunlight is absorbed to offset that infrared cooling.

ANSWER: An anti-cyclone

Explanation:

• Currently, there is an anti-cyclone (circulation of winds around a region of high atmospheric pressure) in the Bay of Bengal.
• This is not allowing advection, which means the sea breeze that helps in cooling the temperatures is not (flowing towards the land) happening.
• The combined effect is leading to heat wave conditions.

ANSWER: Gas Bubbles

Explanation:

• Scientists have invented a new way to deliver cancer drugs deep into tumour cells using gas bubbles, a finding which may solve some of the most pressing problems faced in chemotherapy.
• Researchers from Nanyang Technological University (NTU) in Singapore created micro-sized gas bubbles coated with cancer drug particles and iron oxide nanoparticles, and then used magnets to direct these bubbles to gather around a specific tumour.
• Ultrasound was then used to vibrate the microbubbles, providing the energy to direct the drug particles into a targeted area.
• The main issue is that current chemotherapy drugs are largely non-targeted. The drug particles flow in the bloodstream, damaging both healthy and cancerous cells.
• Typically, these drugs are flushed away quickly in organs such as the lungs and liver, limiting their effectiveness.
• The remaining drugs are also unable to penetrate deep into the core of the tumour, leaving some cancer cells alive, which could lead to resurgence in tumour growth.
• The first unique characteristic of the microbubbles is that they are magnetic. After injecting them into the bloodstream, scientists are able to gather them around the tumour using magnets and ensure that they do not kill the healthy cells.
• More importantly, their invention is the first of its kind that allows drug particles to be directed deep into a tumour in a few milliseconds. They can penetrate a depth of 50 cell layers or more - which is about 200 micrometres, twice the width of a human hair.
• This helps to ensure that the drugs can reach the cancer cells on the surface and also inside the core of the tumour.
• For anticancer drugs to achieve their best effectiveness, they need to penetrate into the tumour efficiently in order to reach the cytoplasm of all the cancer cells that are being targeted without affecting the normal cells.
• Currently, these can be achieved by means of a direct injection into the tumour or by administering a large dosage of anticancer drugs, which can be painful, expensive, impractical and might have various side effects.