Hair is made of a tough protein called keratin. A hair follicle anchors each hair into the skin. The hair bulb forms the base of the hair follicle. In the hair bulb, living cells divide and grow to build the hair shaft. Blood vessels nourish the cells in the hair bulb, and deliver hormones that modify hair growth and structure at different times of life.
Phylum definition, Biology. the primary subdivision of a taxonomic kingdom, grouping together all classes of organisms that have the same body plan. See more. Dictionary.com
In that system, bacteria are members of the domain Bacteria and phylum is the rank below domain as the rank kingdom is disused at present in bacterial taxonomy.In this classification scheme, Bacteria is (unofficially) subdivided into over 29 phyla with representatives cultured in a lab.any major clades of bacteria that exist but cannot currently be cultured are known solely via metagenomics and are called candidate phyla. If these are included, the number of phyla is 52 or higher. Therefore, the number of major phyla has increased from 12 identifiable lineages in 1987, to 52 as of 2003.