The Integument:List the embryonic germ layers from which the epidermis and dermis arise (be specific to the dermis). (2 points) The dermis derives from the mesoderm. It consists of layers of cells that originate from the lowest layer called the basal layer, which is constantly undergoing mitosis. The epidermis derives from the ectoderm. The development of hair, feathers, teeth and scales all depend on the same structure. What is his name? (2 points) Dermal papillaHow do the scales of reptiles differ from those of fish? (2 points) Reptile scales are found in the epidermis of the skin while fish scales are found in the dermis of the skin which lies beneath the epidermis. All reptile scales have a dermal papilla underlying the epidermal part. Compare and contrast rhino horns, antlers, and giraffe antlers in terms of the contribution of the epidermis and dermis. (4 points) Horns are composed of a bony core covered by a keratin sheath. Unlike antlers, antlers are never branched. Rhino horns differ from true horns in that they have no core or sheath. They are made up of numerous epidermal cells and bundles of dermal papillae, extensions of the dermis. The cells of each papilla form a horny fiber similar to a thick hair. These fibers are not real hair. True hairs grow from follicles that extend into the dermis, while rhino horns grow from dermal papillae that extend into the horn. Giraffe horns are paired, short, permanent bony processes covered with skin and hair. They differ from other horns in that they do not protrude from the frontal bones, but are located above the sutures between the frontal and parietal bones. Horns do not form in the epidermis and are not made of keratin but are... paper central ......rdle is attached to the axial skeleton. (5 points) Fish fins have some basic structures in common. What are the two groups of skeletal elements that make up the basic fin of the fish? What type of paired fin does it have: 1) both preaxial and postaxial elements, 2) only preaxial elements? (4 points) Two sets of skeletal elements that make up the basic fin of the fish are the Archipterygial and Metapterygial fins. The archipterygium has both preaxial and postaxial elements. The metapterygium has only preaxial elements. How do artiodactyls differ from perissodactyls? (2 points) Artiodactyla are even-toed ungulates whose weight is supported equally by the third and fourth toes, rather than mainly or entirely by the third as in odd-toed ungulates called perissodactyls. Perissodactyls have an odd number of toes, and the middle toe of each hoof is usually larger than that of its neighbors.