• Mechanisms of Ovulation in Mammals:
• Reflex / Induced Ovulators: Ovulation does not occur spontaneously at the end of the follicular phase; mechanical coital stimulation of vaginal/cervical sensory mechanoreceptors is strictly required to trigger a neuroendocrine surge of GnRH and LH.
• Examples: Cat (Queen), Rabbit (Doe), Camel (Camelus), Ferret, Mink.
• Spontaneous Ovulators: Cyclic rising levels of follicular estradiol trigger the pre-ovulatory LH surge and ovulation independently of copulation:
• Examples: Dog (Bitch), Cow, Mare, Ewe, Sow, Human.
• nalysis:
• (Dog): Correct (spontaneous ovulator, not a reflex ovulator).

Correct option: (2) Dog

• 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

• Thermoregulatory Thermal Comfort Zones in Cattle:
• Upper Critical Temperature (UCT) is the ambient environmental temperature above which an animal must actively expend metabolic energy (sweating, panting) to dissipate heat and prevent lethal hyperthermia.
• Bos indicus (Zebu cattle - Hariana breed):
• Possess numerous large, functional sweat glands, sleek reflective coats, loose vascular skin with extensive dewlap/umbilical fold surface area, and lower basal metabolic rates.
• They have the highest UCT ($\approx 35 - 38^\circ\text{C}$) among cattle breeds.
• Bos taurus (Holstein Friesian, Jersey):
• Adapted to temperate climates; exhibit heavy heat stress with a lower UCT of $\approx 24 - 27^\circ\text{C}$.
• nalysis:
• (Hariana): Correct breed with the highest UCT.

Correct option: (2) Hariana