What is rachis in feather?
In feather. …of a central shaft (rachis), with serial paired branches (barbs) forming a flattened, usually curved surface—the vane. The barbs possess further branches —the barbules—and the barbules of adjacent barbs are attached to one another by hooks, stiffening the vane.
Do down feathers have rachis?
Similar to semiplumes with an even looser branching structure but little or no central rachis, down feathers are relatively short and positioned closest to the body where they trap body heat.
What are Semiplume feathers?
Semiplume feathers are a cross between down and contour feathers. Unlike down, they do have a well formed shaft. However, they do not have well developed barbicels which make them soft. Semiplume feathers are found underneath contour feathers and are used for insulation. Filoplume feathers are incredibly small.
What is rachis in birds?
The main shaft of a bird’s feather, especially the part to which the barbs are attached. The main shaft of a bird’s feather, especially the part to which the barbs are attached.
What are 5 functions of feathers?
What are the functions of feathers? (Answers: flight, insulation, defense, display, camouflage, waterproofing)
Is rachis a petiole?
The term “petiole” refers to the portion of the leaf between the leaf base and the leaf blade. The term “rachis” refers to the extension of the petiole into the leaf blade that the leaflets are attached to in a pinnate leaf palm. The leaves of pinnate leaf palms have both a petiole and a rachis.
What are the two main types of feathers?
There are two basic types of feather: vaned feathers which cover the exterior of the body, and down feathers which are underneath the vaned feathers. The pennaceous feathers are vaned feathers. Also called contour feathers, pennaceous feathers arise from tracts and cover the entire body.
What are the two types of feathers?
What is the function of a rachis?
In zoology and microbiology In vertebrates, rachis can refer to the series of articulated vertebrae, which encase the spinal cord. In this case the rachis usually forms the supporting axis of the body and is then called the spine or vertebral column. Rachis can also mean the central shaft of pennaceous feathers.
What are 4 functions of feathers?
Feathers perform a number of functions for a bird: 1) They provide insulation, body temperature of most birds is maintained at around 40 C; 2) Feathers allow for flight; 3) Feathers control what a bird looks like by supplying the bird with colors.
What is the role of the feathers?
A bird’s feathers play an important role in regulating their body temperature, much as hair does for mammals. Camouflage. Like many other members of the animal kingdom, some birds have the natural ability to blend into their surroundings. This helps them stay hidden from predators or sneak up on potential prey.
What is a flattened petiole?
A pulvinus on a petiolule is called a pulvinulus. In some plants, the petioles are flattened and widened to become phyllodes (aka phyllodia or cladophylls) and the true leaves may be reduced or absent. Thus, the phyllode comes to serve the functions of the leaf.