Dense fur in cold temperature animals protect these from-

Correct Answer: D

Rationale: The correct answer is D: Cold. Dense fur in cold temperature animals acts as insulation to retain body heat and protect them from the cold. The fur traps air close to the body, creating a layer of warmth. This helps regulate their body temperature and prevent heat loss. Snow (A) is not the main threat as the fur insulates against it. Air (B) is actually trapped by the fur to provide insulation. Enemies (C) are not directly protected against by dense fur, as it primarily serves to regulate body temperature in cold environments.

Correct Answer: B

Rationale: Correct Answer: B Rationale: 1. Melanin is produced from the amino acid tyrosine, making choice A true. 2. Melanin protects DNA from UV radiation, making choice C true. 3. Melanin is usually some shade of brown or black, making choice D true. 4. Melanin actually increases in concentration within cells during exposure to the sun to provide more protection, making choice B false. Summary: Choices A, C, and D are true statements about melanin. Choice B is incorrect as melanin increases in concentration during sun exposure.

Correct Answer: A

Rationale: The correct answer is A: Dermatitis. Dermatitis refers to skin inflammation, and when it primarily involves the papillary layer (located in the dermis), it is termed papillary dermatitis. This layer contains blood vessels, nerves, and collagen fibers, making it a common site for inflammation. The other choices are incorrect because: B: Papillitis specifically refers to inflammation of the papillae on the tongue or eye. C: Epidermatitis would suggest inflammation of the epidermis layer, not the papillary layer. D: Melanocytic relates to melanocytes, which are pigment-producing cells in the skin, not inflammation of the papillary layer.

Correct Answer: A

Rationale: The correct answer is A. Accessory structures of the integument, like hair and nails, do not provide direct protection to the skull. Skull protection primarily comes from the cranial bones and meninges. Hair and nails are involved in thermoregulation, sensation of touch, and production of skin pigments. Therefore, choice A is incorrect as the accessory structures do not directly protect the skull but serve other functions related to the integument system.

Correct Answer: A

Rationale: The correct answer is A: stratum corneum. This is the outermost layer of the epidermis composed of dead skin cells filled with keratin. It provides protection against environmental factors. Stratum spinosum (B) is a layer below the stratum corneum, stratum basale (C) is the deepest layer where cells divide, and stratum granulosum (D) is a layer above the stratum corneum where cells start to flatten and keratinize. The stratum corneum is the toughest and most superficial layer, making it the correct choice.