Pigmented cells are found amongst the cells of -

Correct Answer: A

Rationale: The correct answer is A: Stratum malpighi. Pigmented cells, known as melanocytes, are found in the stratum malpighi layer of the epidermis. Melanocytes produce melanin, a pigment that gives skin its color and protects against UV radiation. The other choices (B: Stratum granulosum, C: Stratum lucidum, D: Stratum corneum) do not contain pigmented cells. Stratum granulosum is where keratinization occurs, stratum lucidum is a translucent layer found only in thick skin, and stratum corneum is the outermost layer composed of dead keratinocytes.

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.

Correct Answer: B

Rationale: The correct answer is B: Tanning. Tanning is the process of converting raw animal hides into leather by treating them with chemicals to preserve and strengthen the material. Taxidermy is the preserving of animal bodies, not the formation of leather. Keratinization is the process of converting soft tissues into hard structures like hair and nails, not the formation of leather. So, tanning is the only choice directly related to the formation of leather from the skin.