Epidermis of skin in rabbit is originated from-

Correct Answer: C

Rationale: The epidermis of the skin in a rabbit originates from the ectoderm. During embryonic development, the ectoderm gives rise to the outermost layer of the skin, which includes the epidermis. The ectoderm is the primary germ layer that forms the skin, nervous system, and other structures derived from the outer layer of the embryo. The endoderm gives rise to the innermost layer of the skin, while the mesoderm forms the middle layer. Therefore, the correct answer is C (Ectoderm). Choices A, B, and D are incorrect because the epidermis does not originate from the endoderm, mesoderm, or all germ layers, but specifically from the ectoderm during embryonic development.

Correct Answer: A

Rationale: The correct answer is A: Dermis of palms. The dermis of the palms is highly developed in laborers due to constant friction and pressure from manual labor. This layer thickens to provide protection and support. The subdermal layer is not typically highly developed in response to labor, and the epidermal layer may thicken but is not the primary layer affected. Choice D is incorrect because not all layers of the skin are equally affected by manual labor.

Correct Answer: B

Rationale: The correct answer is B: Skin is not slimy. Mucous glands produce a slimy substance called mucus, which serves to lubricate and protect various surfaces in the body. Skin in mammals is not supposed to be slimy, as it needs to maintain a dry and protective barrier. A: Skin does respire through diffusion, but this does not relate to the presence of mucous glands. C: Skin does have blood vessels for nourishment and temperature regulation, but this does not explain the absence of mucous glands. D: The presence of strata of cells in the outer skin layer is related to its protective function and does not directly influence the absence of mucous glands.

Correct Answer: B

Rationale: The correct answer is B: Perineal glands. Perineal glands are scent glands found in animals to produce pheromones. These glands are responsible for emitting scents used in communication and territorial marking. Zeis glands are sebaceous glands in the eyelids, Ceruminous glands produce earwax, and Sweat glands produce sweat for thermoregulation. Therefore, perineal glands are the only glands specifically known for producing scents.

Correct Answer: A

Rationale: The dermis is mainly composed of fibrous connective tissue, which provides structural support and flexibility to the skin. This tissue contains collagen and elastin fibers, giving the skin its strength and elasticity. Nerve fibers and receptors are present in the dermis for sensation, but they are not the main component. Blood capillaries supply nutrients and oxygen to the skin, but they are not the primary composition of the dermis. Elastin proteins are important for elasticity, but they are a component within the fibrous connective tissue in the dermis. Therefore, choice A is correct as it accurately represents the main composition of the dermis.