CHAPTER 5 and 6

3. meaning "live" and "birth".
6. a process wherein various protein products accumulate and collectively form keratin.
7. usually found around the snouts of many mammals.
9. composed of concentric rings or circuli.
10. the time the embryo develops within the female.
11. the act of laying eggs.
14. type of feather that often specialized for display.
16. tissues are formed of closely adjoined cells with every little extracellular matrix between them.
17. produce an oily secretion,sebum.
19. meaning "gut" and "formation".
20. beneath the guard hairs and usually much finer and shorter.
24. produce milk.
25. process of forming an ectodermal tube,the neural tube.
28. composed of many secretory cells.
29. type of feather that aerodynamically shape the surface of the bird.
34. a circular pigmented area of skin found around the nipples.
35. with a fringe of projection along its posterior margin.
37. type of feather that constitute the major aerodynamic surfaces.
38. male gamete.
39. type of feather lie close to the skin as thermal insulation.
40. a diverse cell found in the skin of lampreys and other fishes.
41. a cap of cells arched over a small blastocoel.

1. "bone formation".
2. characterized by the prevalance of thick surface coat enamel,without an underlying layer of dentin.
4. are slender,keratinous filaments.
5. the act of giving birth via viviparity.
8. the cells resulting from these early cleavage divisions of the ovum.
12. female gamete.
13. meaning "egg" and "birth".
15. embryos that draw nutrients from the yolk of the ovum.
18. the down feathers.
21. it lacks on enamel,dentin and a vascular bone layer.
22. the contour feathers.
23. tissues that includes bones,cartilage,fibrous connective tissue,adipose tissue and the blood.
26. meaning "tissue formation".
27. release of milk to a suckling.
30. the base of a hair.
31. has only single secretory cell.
32. meaning "organ" and "formation".
33. found in porcupines that are stiff,coarse hairs specialized for defense.
36. union of two or more gametes.