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.
heptane. n. 1. (Elements & Compounds) an alkane existing in nine isomeric forms, esp the isomer with a straight chain of carbon atoms (n-heptane), which is found in petroleum and used as an anaesthetic. Formula: C7H16. [C19: from hepta- + -ane, so called because it has seven carbon atoms].