UGC NTA NET/JRF Exam, Environmental Sciences, June-2023

(b) In this step, you establish the null hypothesis, which typically states that there is no association between the two characteristics being studied. The null hypothesis is a starting point for statistical testing.

(c) Create a contingency table that organizes the data based on the two characteristics under investigation (e.g., Gender and discomfort due to humidity). This table displays the frequencies or counts of observations in each combination of categories.

(e) Using the marginal totals from the contingency table and assuming independence (no association), calculate the expected frequencies for each cell in the table.

(d) For each cell in the contingency table, calculate the squared difference between the observed and expected frequencies, divide this by the expected frequency, and sum these values across all cells.

(a) Once you have the calculated Chi-square statistic from step 4, compare it with the critical or tabulated value from the Chisquare distribution table.

If the calculated value is greater than the critical value, you may reject the null hypothesis, suggesting a significant association between the two characteristics.

(a) This statement is true. While the ozone layer significantly absorbs UV-B radiation, it doesn't block it completely. Some UV-B still reaches the Earth's surface, contributing to sunburn and other skin damage.

(b) This statement is true. Compared to UVB, UV-A has longer wavelengths and lower energy, making it less harmful to biological systems. While UV-A can cause tanning and premature aging, it doesn't have the same detrimental effects on DNA and cell structure as UV-В.

(d) This statement is true. Sunscreen protects our skin from UV radiation by employing various mechanisms: reflecting, absorbing, and scattering UV rays.

(e) This statement is true. UV-B radiation has enough energy to break apart the O₃ molecule into an oxygen atom (O) and an oxygen molecule (O₂).

Wangari Muta Maathai was a prominent Kenyan environmentalist and political activist, best known for her association with the Green Belt Movement.

Founded in 1977 by Maathai, the Green Belt Movement aimed to address environmental conservation, women's rights, and community development simultaneously.

The movement encouraged women to plant trees as a means to combat deforestation, soil erosion, and to promote sustainable environmental practices.

Under Maathai's leadership, the Green Belt Movement became a powerful force for change, empowering women through environmental initiatives and advocating for social and political justice.

The National Action Plan for Climate Change (NAPCC) in India outlines various National Missions to address the challenges posed by climate change. Among these missions, the National Mission for a Clean India is not explicitly listed.

The missions included in the NAPCC are designed to tackle different aspects of climate change and sustainability.

While initiatives for a clean environment are integral to climate change mitigation and adaptation, the specific formulation of a National Mission for a Clean India might be addressed through other national programs outside the NAPCC framework, such as Swachh Bharat Abhiyan, which focuses on sanitation and cleanliness.

Project Tiger is a tiger conservation program that celebrated its 50th anniversary on April 1, 2023. The Government of India launched the program in April 1973, during the tenure of Prime Minister Indira Gandhi.

The program has helped endangered wild tigers in India recover. In 1973, there were nine reserves covering 9,115 square kilometers.

Today, there are 54 reserves in 18 states, covering 78,135.956 square kilometers, or 2.38% of India's total land area.

The project's primary objective is to ensure the survival and maintenance of the tiger population in their natural habitats by creating dedicated Tiger Reserves. The project was launched on April 1, 1973 from the Jim Corbett National Park of Uttarakhand.

Sustainable Development Goal 10 (SDG-10) aims at reducing inequalities within and among countries. It underscores the importance of addressing disparities in income, social status, opportunities, and access to basic services.

The goal recognizes that inequality poses significant challenges to sustainable development, hindering poverty reduction efforts, and fostering social unrest.

SDG-10 seeks to empower and promote the social, economic, and political inclusion of all individuals, regardless of their background, in order to create a more just and equitable global society.

(b) Chernobyl Disaster, 1986: The Chernobyl Disaster occurred on April 26, 1986, at the Chernobyl Nuclear Power Plant in Pripyat, Ukraine, which was part of the Soviet Union at the time.

It is considered the worst nuclear disaster in history. The disaster resulted from a reactor explosion during a safety test, leading to the release of a large amount of radioactive material into the atmosphere.

The immediate impact caused the deaths of two plant workers, and the subsequent contamination had severe health and environmental consequences for the region and beyond.

(c) Fukushima Disaster, 2011: The Fukushima Disaster occurred on March 11, 2011, following a massive earthquake and tsunami in Japan.

The natural disasters damaged the Fukushima Daiichi Nuclear Power Plant, leading to meltdowns in three of its reactors.

The event resulted in the release of radioactive materials and forced the evacuation of nearby residents.

In epidemiology, a case-control study is a research design aimed at investigating the association between a specific disease and potential risk factors or exposures.

This study begins by identifying a group of individuals with the particular disease of interest (cases) and a comparable group without the disease (controls).

Researchers then retrospectively analyze and compare the past exposures, behaviours, or characteristics of these two groups to identify commonalities or differences that may be associated with the disease.

By comparing the odds of exposure between cases and controls, investigators can assess potential risk factors and gain insights into the etiology of the disease.