UPSC Prelims 2014 Analysis

Explanation

1. Vitamin C deficiency causes Scurvy is right.

2. Vitamin D deficiency causes Rickets is right.

3. Vitamin E deficiency causes Night blindness is wrong. As Vitamin A deficiency causes Night blindness.

Explanation

The Government introduced the Pentavalent vaccine, which also fights against Diphtheria . This implies that Diphtheria is still prevalent.

Additionally, Chickenpox is still widespread among the population.

However, it's important to note that Smallpox has been eradicated from India. India declared itself free of smallpox in 1979.

Explanation

Messenger Mapping and investigating Mercury

Voyager 1 and 2 Exploring the outer solar system

Cassini-Huygens studied Saturn, not Venus. Therefore, 1 is wrong.

Explanation

During photosynthesis, solar energy is converted into chemical energy and stored in sugar molecule bonds. This chemical bond energy is potential (stored) energy.

Explanation

Agni-IV is indeed a surface-to-surface missile. It is designed to launch from land-based mobile platforms and strike targets on the ground. Thus, statement 1 is correct.

Agni-IV is a two-stage, solid-fueled missile. It does not rely on liquid propellants. Thus, statement 2 is incorrect.

The reported range of Agni-IV is around 4,000 km, not 7,500 km. Additionally, its payload capacity is estimated to be around 1,000 kg (one tonne), but its specific warhead capabilities are not publicly disclosed. Thus, statement 3 is also incorrect.

Explanation

The first statement is correct because plants produced by vegetative propagation are exact copies of the parent plant, as theyre produced from a single parent.

Vegetative propagation may not eliminate viruses. If a virus is present in the parent plant, it will likely be passed on to the new plants as well. So, statement 2 is incorrect.

Statement 3 is correct because Vegetative propagation can be practised most of the year.

Explanation

Biometric verification is any means by which a person can be uniquely identified by evaluating one or more distinguishing biological traits . Unique identifiers include

• Fingerprints
• Hand geometry
• Earlobe geometry
• Retina and iris patterns
• Voice waves
• DNA
• Signatures .

Explanation

Mites, scorpions, and spiders are all classified within the class Arachnida.

Crabs, although arthropods like the others belong to the class Crustacea.

Therefore, the crab is the odd one out due to its different taxonomic classification.

Explanation

Crystallization of sodium chloride This is a physical change. The sodium chloride (table salt) is changing its form from a dissolved state in water to a solid crystal structure, but the chemical composition remains NaCl.

Melting of ice Similar to crystallization, melting of ice is a physical change. Water (H2O) molecules are rearranging from a rigid solid structure to a more fluid liquid state, but the chemical makeup stays the same.

Souring of milk This is a chemical change. Milk sugar (lactose) is broken down by bacteria into lactic acid. This process involves the formation of new substances and alters the chemical composition of the milk.

Therefore, only statement 3 is an example of chemical change.

Explanation

A transgenic crop is a genetically modified organism (GMO).

Transgenic indicates that a transfer of genes has occurred using recombinant DNA technology. Generally, a transgenic crop contains one or more genes that have been inserted artificially either from an unrelated plant or from different species altogether.

Budding and grafting in fruit plants does not include genetic editing or modification. Thus, option 1 is eliminated.

Gene silencing technique uses engineered genetic material to specifically suppress the expression of certain genes in a plant. This allows scientists to modify the plant's characteristics at the genetic level, which is the hallmark of transgenic crops.

Thus, option 3 must be part of the answer, accordingly right answer is option 'B'.

Explanation

Hibernation is a state of decreased physiological activity and lowered body temperature that certain animals, such as bats and bears, undergo during the winter months to conserve energy and survive periods of limited food availability.

Bats, especially those living in temperate regions, often enter a state of hibernation during the colder months when their food sources (insects) are scarce.

Similarly, Bears, including the brown bear, black bear, and polar bear, are well-known hibernators.

Rodents many species, including groundhogs and chipmunks, are true hibernators.

Thus, all the three statements are correct.