Which type of feather disintegrates as it grows, releasing a talc-like substance to waterproof the feathers?

Will someone me with this.. specialized cells which perform a particular function form: tissues organs or organism

Zoo geographic regions are characterized by the presence of specific groups of animals these regions are determined by the taxonomic or phylogenetic relationships of animals. the map shows the zoogeographic regions proposed by the naturalist alfred russel wallace in 1876. the similarities of organisms in which two areas numbered above provide the best evidence for common ancestry between the organisms in both locations ?

Which term specifically refers to an area of the body between a medial and lateral structure