Explanation : 

Acid Rain and Its Primary Causes

Acid rain is a term that refers to a mixture of wet and dry deposition from the atmosphere containing higher than normal amounts of nitric and sulfuric acids. The primary causes of acid rain are emissions of sulfur dioxide (SO2) and nitrogen oxides (NOx), which react with the water molecules in the atmosphere to produce acids.

Key Pollutants Involved in Acid Rain

Carbon monoxide (CO) is a colorless, odorless, and toxic gas, but it does not contribute to acid rain. It is primarily a concern because it can be harmful to human health, particularly in enclosed spaces.

Nitrogen oxides (NOx), including nitrogen dioxide (NO2) and nitric oxide (NO), are significant contributors to acid rain. They react with water, oxygen, and other chemicals in the atmosphere to form nitric acid, which can then fall to the ground in precipitation, contributing to the acidification of ecosystems.

Ozone (O3) is a molecule composed of three oxygen atoms. It is not a direct contributor to acid rain. Ozone at ground level is a harmful air pollutant and a key component of smog, but it does not form acidic compounds that lead to acid rain.

Sulfur dioxide (SO2) is a gas that is produced by volcanic eruptions and industrial processes, particularly the combustion of coal and oil at power plants and the smelting of mineral ores that contain sulfur. In the atmosphere, SO2 can oxidize to form sulfuric acid (H2SO4), which is a major component of acid rain.

Therefore, the correct answer is “2 and 4 only” because nitrogen oxides and sulfur dioxide are the pollutants that contribute to acid rain, while carbon monoxide and ozone do not.

Explanation : 

DNA Barcoding

DNA barcoding is a method of species identification using a short section of DNA from a specific gene or genes. The concept is based on the fact that there is enough variation in the DNA sequences between different species to allow for identification, much like how a barcode identifies different products in a store.

Does DNA Barcoding Assess the Age of Organisms?

DNA barcoding does not provide information about the age of a plant or animal. The age of an organism is not encoded in the DNA sequences used for barcoding. Therefore, this statement is incorrect.

Identification of Cryptic Species

DNA barcoding is particularly useful for distinguishing between species that look very similar to one another, also known as cryptic species. Morphological identification can be challenging or even impossible in some cases, but DNA barcoding allows for precise identification based on genetic differences. Therefore, this statement is correct.

Detecting Food Fraud and Allergens

DNA barcoding can be used to identify components of processed foods, ensuring that the ingredients are correctly labeled and that no undesirable or mislabeled animal or plant materials are present. This application is particularly important for detecting food fraud, allergens, or the presence of species that are not supposed to be in the food product. Therefore, this statement is correct.

Explanation : 

Explanation : 

B Cells in the Adaptive Immune System

B cells, or B lymphocytes, are white blood cells that play a key role in the humoral immune response. They are responsible for producing antibodies, which are specific proteins that bind to antigens on the surface of pathogens or infected cells. When B cells encounter an antigen that matches their specific antibody, they can differentiate into plasma cells that secrete large quantities of antibodies into the bloodstream. These antibodies neutralize pathogens by blocking their ability to infect cells, tagging them for destruction by other immune cells, or activating the complement system to destroy the pathogen.

T Cells in the Adaptive Immune System

T cells, or T lymphocytes, are another type of white blood cell that is essential for the adaptive immune response. There are several types of T cells, including helper T cells (CD4+ T cells) and cytotoxic T cells (CD8+ T cells).

Helper T Cells

Helper T cells assist in activating and directing other immune cells, including B cells and cytotoxic T cells. They release cytokines that help orchestrate the immune response.

Cytotoxic T Cells

Cytotoxic T cells directly kill infected cells by recognizing small fragments of antigens (peptides) presented on the surface of these cells by major histocompatibility complex (MHC) class I molecules.

Regulatory T Cells

Another subset of T cells, regulatory T cells (Tregs), help maintain immune tolerance and prevent autoimmune responses by suppressing the activity of other immune cells.

Explanation : 

Somnath Temple: A Revered Jyotirlinga Shrine

The Somnath Temple is indeed one of the twelve Jyotirlinga shrines which are highly revered in Hinduism. These shrines are considered to be the most sacred abodes of Shiva. Each of the twelve Jyotirlinga sites take the name of the presiding deity, each considered a different manifestation of Shiva. Somnath is located in Prabhas Patan near Veraval in Saurashtra, on the western coast of Gujarat, India.

Al-Biruni’s Account of Somnath

The second statement is also correct. The Arab traveler Al-Biruni visited India in the 11th century and described the Somnath Temple in his memoirs. His account provides valuable information about the history of the temple and its significance at that time.

Pran Pratistha of Somnath Temple

However, the third statement is incorrect. The Pran Pratistha (consecration) of the present-day Somnath Temple was not done by President S. Radhakrishnan. The temple was reconstructed several times in the past after being destroyed by various invaders. The final reconstruction of the temple in its current form was completed in December 1951, and the Pran Pratistha was performed by the then President of India, Dr. Rajendra Prasad, not S. Radhakrishnan.

Therefore, the correct answer is “1 and 2 only”.

Explanation : 

Ramanuja: A Pioneering Theologian and Philosopher

Ramanuja was an influential theologian, philosopher, and one of the most important exponents of the Sri Vaishnavism tradition within Hinduism. His philosophical foundations for devotionalism were influential to the Bhakti movement.

Ramanuja’s Teachings and Devotion to Vishnu

Ramanuja’s teachings focused on the importance of personal devotion to Vishnu as the supreme God and the use of the Lord’s grace in achieving salvation. He advocated for surrender to God (prapatti) and devotion (bhakti) as the best means to attain moksha, or liberation from the cycle of birth and death.

Therefore, the correct answer to the question is:
a) The best means of salvation was devotion.

Explanation : 

Vasishta Yoga Samhita (Sanskrit: योगवासिष्ठम्, IAST: yoga-vāsiṣṭham; also known as Maha-Ramayana, Arsha Ramayana, Vasiṣṭha Ramayana, Yogavasistha-Ramayana and Jnanavasistha.) is a historically popular and influential syncretic philosophical text of Hinduism, dated to the 1st-3rd century BCE. It is attributed to Maharishi Valmiki, but the real author is unknown. The complete text contains over 29,000 verses. The short version of the text is called Laghu yogavāsiṣṭham and contains 6,000 verses.

During the Mughal Dynasty the text was translated into Persian several times, as ordered by Akbar, Jahangir and Darah Shikuh. One of these translations was undertaken by Nizam al-Din Panipati in the late sixteenth century AD. This translation, known as the Jug-Basisht, which has since become popular in Persia among intellectuals interested in Indo-Persian culture. The Safavid-era mystic Mir Findiriski (d. 1641) commented on selected passages of Jug-Basisht.

Source – Yoga Vasistha – Wikipedia

Explanation : 

Sangam-Era Poets and Social Stratification

During the Sangam era, poets were cognizant of the social stratification known as varna. They referenced Arashar (monarchs), Vaishiyar (merchants), and Velalar (agriculturists). Brahmanas are also mentioned, with some having strong ties to royal courts and enjoying the patronage of the elite. However, the rigid four-tier varna system did not significantly influence ancient Tamil society. Contrary to the prevalent varna system, the ancient Tamil society was not significantly impacted by the rigid four-tier structure. Similarly, the jati system, which is a sub-categorization within the varna, did not play a role in this society. Therefore, the observation that the jati system was non-influential stands true.

Explanation : 

Historical Records and Dynastic Associations

Based on historical records, Nanuka (also known as Nannuka or Nannuk) is indeed associated with the Chandela dynasty. He is considered the founder of the Chandela dynasty in central India.

Jayashakti is not correctly matched with the Parmara dynasty. He was a ruler from the Chandela dynasty.

Gurjara-Pratihara and Paramara Dynasties

Nagabhata II is correctly matched with the Gurjara-Pratihara dynasty. He was a prominent ruler of the Gurjara-Pratihara dynasty, known for defending his kingdom against the Arab invasions from the west.

Bhoja is not correctly matched with the Rashtrakuta dynasty. Bhoja was a king of the Paramara dynasty that ruled in the region of Malwa in central India. He is known for his patronage of the arts, literature, and architecture.

Therefore, out of the four pairs, only two pairs are correctly matched:
1. Nanuka – Chandela
3. Nagabhata II – Gurjara-Pratihara

The correct answer is: Only two pairs

Explanation : 

Ashoka’s Major Rock Edicts and Their Locations

The correct answer to the matching of the sites of Ashoka’s major rock edicts and their locations is b) Only two pairs.

Correctly Matched Pairs

Dhauli in Odisha is known for its rock edicts and is correctly matched as such. Similarly, the Erragudi rock edicts are indeed located in Andhra Pradesh, making this pair another correct match.

Incorrectly Matched Pairs

However, the pair Jaugada – Madhya Pradesh is incorrect, as Jaugada is actually situated in Odisha. The pair Kalsi – Karnataka is also incorrect because Kalsi is found in Uttarakhand, not Karnataka.

Thus, the answer is b) Only two pairs.