Which of the following animal is having sweat glands only on pinnae

Correct Answer: A

Rationale: The correct answer is A: Rhinoceros. Rhinoceros is the only animal among the options that has sweat glands only on its pinnae (ears). The other choices, Deer, Hippopotamus, and Rabbit, have sweat glands distributed throughout their bodies or in different areas, not just on the pinnae. This unique anatomical feature of the Rhinoceros helps it regulate body temperature by cooling the blood vessels around the ears. Therefore, Rhinoceros is the correct answer based on the specific location of its sweat glands.

Correct Answer: C

Rationale: The correct answer is C because the dermis is the layer of skin that provides strength, flexibility, and elasticity, making it suitable for shoe leather. Choice A is incorrect because the presence of cells alone doesn't determine leather quality. Choice B is incorrect as hardness is not a desirable quality for shoe leather. Choice D is incorrect as ecdysis refers to the shedding of skin by animals, not the process of obtaining leather.

Correct Answer: A

Rationale: The correct answer is A: Arrector muscles. Arrector muscles are responsible for pulling the hair follicles and hairs upright when the temperature is low, a response known as piloerection. This physiological response helps to trap heat and maintain body temperature. Abductor muscles (Choice B) are not involved in hair erection. Petrihydroid muscles (Choice C) and Contractor muscles (Choice D) are not anatomical terms related to hair erection.

Correct Answer: B

Rationale: The correct answer is B: Meissner's corpuscles. Meissner's corpuscles are responsible for detecting light touch and low-frequency vibration. They are located in the upper dermis and have rapidly adapting receptors, making them sensitive to changes in stimuli. Pacinian corpuscles (A) detect deep pressure and high-frequency vibration, Krause's bulbs (C) detect cold temperatures, and Corpuscles of Ruffini (D) detect skin stretching and continuous pressure. Meissner's corpuscles specifically match the description of touch receptors in mammalian skin, making it the correct choice.

Correct Answer: D

Rationale: The correct answer is D: Almost hairless skin. Elephants living in hot climates need to regulate their body temperature efficiently. Having almost hairless skin helps them dissipate heat effectively through their skin. This adaptation is crucial for elephants to thrive in hot environments. A: Its huge size is not a direct indicator of its ability to survive in a hot climate. B: Small eye size is not necessarily related to their adaptation to hot climates. C: Fleshy feet do not specifically indicate their preference for hot climates.