Fundamental Cellular Processes

• Historic Cloned Mammals:
• Cloned Sheep:
• Dolly (1996): First mammal cloned from adult somatic cells.
• Megan and Morag (1995): First cloned sheep from differentiated embryonic cell lines.
• Polly (1997): First transgenic cloned sheep bearing human factor IX gene.
• Xena (2000):
• The world's first cloned pig (porcine), produced from adult granulosa cells via SCNT.
• nalysis:
• (Xena): Correct (Xena is a cloned pig, not a sheep).

Correct option: (2) Xena

• Honolulu Technique for Mouse Cloning (Wakayama et al., 1998):
• Teruhiko Wakayama and colleagues at the University of Hawaii created the first cloned mice ("Cumulina") using adult cumulus cell nuclei.
• Unlike Dolly the sheep where cell fusion was induced by electric pulses (electrofusion), mouse oocytes are mechanically fragile and often lyse upon electrical pulse application.
• Wakayama developed a piezo-actuated micromanipulation system to perform direct intracytoplasmic microinjection of the donor nucleus into enucleated metaphase II oocytes.

Correct option: (1) Direct intra-cytoplasmic injection of the nucleus.

• Aerobic Energy Generation:
• Assertion (A): Under aerobic conditions, the tricarboxylic acid (TCA) cycle coupled with the electron transport chain represents the cell's primary catabolic generator of metabolic ATP. (True).
• Reason (R): For each turn of the TCA cycle, oxidation of acetyl-CoA reduces 3 molecules of $NAD^+$ to $NADH$ and 1 molecule of $FAD$ to $FADH_2$. The transfer of electrons from these reduced cofactors through the mitochondrial electron transport chain drives oxidative phosphorylation, producing approximately 10 high-energy ATP equivalents per acetyl-CoA. (True).
• nalysis:
• Both (A) and (R) are correct, and (R) is the correct explanation of (A). Hence, Option 1 is correct.