Answer: B. Agmatine

Explanation: Decarboxylation of arginine produces agmatine.

Answer: A. Bat

Explanation: Bats are the natural reservoir for the Nipah virus.

Answer: C. domain

Explanation: A domain is an independently folded and functional unit of a protein.

Answer: D. Sucrose

Explanation: Sucrose does not give a positive Tollen’s test due to the absence of a free aldehyde group.

Answer: C. 10

Explanation: Geranyl pyrophosphate contains 10 carbon atoms.

Answer: A. Isoleucine, threonine

Explanation: Isoleucine and threonine both possess more than one chiral center.

Answer: B. Red blood cell

Explanation: Red blood cells lack nuclei and are not targets for viral infection.

Answer: C. 40S and 60S

Explanation: Eukaryotic ribosomes consist of 40S and 60S subunits.

Answer: B. (A + G) / (T + C)

Explanation: According to Chargaff's rules, (A+G)/(T+C) remains equal under complementary base pairing.

Answer: A. Zinc

Explanation: Zinc is essential for the catalytic activity of many enzymes including carboxypeptidase A.

Answer: B. Ligases

Explanation: DNA ligases catalyze the joining of DNA strands by forming phosphodiester bonds. They are crucial in DNA replication and repair, ensuring the continuity and integrity of the genetic material in cells.

Answer: B. Methine bridges

Explanation: A porphyrin ring is composed of four pyrrole rings linked by methine bridges. This unique structure is essential for the function of heme and chlorophyll in biological systems.

Answer: C. 3

Explanation: Insulin contains three disulfide bonds that are essential for maintaining its tertiary structure. These bonds play a critical role in its biological activity and stability as a peptide hormone.

Answer: D. Sucrose and Trehalose

Explanation: Non-reducing sugars such as sucrose and trehalose lack a free aldehyde or ketone group, preventing them from undergoing redox reactions typical of reducing sugars. Their structure remains stable.

Answer: C. Thymine

Explanation: Thymine is absent in RNA; instead, RNA contains uracil. This distinction is fundamental to nucleic acid chemistry and affects the structure and function of RNA versus DNA.

Answer: A. heating to BP for 15 minutes for 3 successive days

Explanation: Tyndallization is a sterilization method that involves heating a substance to its boiling point for 15 minutes over three consecutive days. This process allows resistant spores to germinate and be subsequently killed in the following cycles.

Answer: A. Henipavirus

Explanation: The Nipah virus belongs to the Henipavirus genus. This classification is based on its genetic and structural characteristics, and the virus is known to cause severe respiratory and neurological diseases.

Answer: A. AUG, AUA and AUU

Explanation: Human mitochondrial genomes utilize alternative start codons such as AUG, AUA, and AUU. These differences from the standard genetic code allow for unique translational mechanisms within mitochondria.

Answer: D. Thymine

Explanation: Deamination of 5-methyl cytosine converts it into thymine. This reaction plays an important role in epigenetic modifications and DNA mutation processes, impacting genetic stability and cellular aging.

Answer: A. IgA

Explanation: IgA is the first line of defense, especially in mucosal areas. It plays a crucial role in immune protection by neutralizing pathogens at the entry points, such as the respiratory and gastrointestinal tracts.