T and B cells. Lymphocytes originate from stem cells in the bone marrow; these stem cells divide continuously, releasing immature lymphocytes into the bloodstream. Some of these cells travel to the thymus, where they multiply and differentiate into T lymphocytes, or T cells.
Cellophane is a thin, transparent sheet made of regenerated cellulose. Its low permeability to air, oils, greases, bacteria and water makes it useful for food packaging. Cellophane is in many countries a registered trade mark of Innovia Films Ltd based in Wigton, Cumbria, United Kingdom.
Xylene (from Greek Î¾ÏÎ»Î¿, xylo, wood), xylol or dimethylbenzene is any one of three isomers of dimethylbenzene, or a combination thereof. With the formula (CH3)2C6H4, each of the three compounds has a central benzene ring with two methyl groups attached at substituents. They are all colorless, flammable liquids, some of which are of great industrial value. The mixture is referred to as both xylene and, more precisely, xylenes.