Plant cell parenchyma cells, that covers the external surfaces of leaves, stems and roots. Several cell types may be present in the epidermis. Notable among these are the stomatal guard cells that control the rate of gas exchange between the plant and the atmosphere, glandular and clothing hairs or trichomes, and the root hairs of primary roots. In the shoot epidermis of most plants, only the guard cells have chloroplasts. Chloroplasts contain the green pigment chlorophyll which is needed for photosynthesis. The epidermal cells of aerial organs arise from the superficial layer of cells known as the "tunica" (L1 and L2 layers)
Australian Stem Cell Centre Australian Stem Cell Centre The Australian Stem Cell Centre is an Australian medical research and development centre which focuses on regenerative medicine through the use of stem cells. Founded in 2003, the Centre is the National Biotechnology Centre of Excellence and has received over $100 million in funding in recent years. It is Australia's premier stem cell research organisation. In June 2008, the Centre announced that it had begun working on induced pluripotent (iPS) cells (human embryonic stem cells, artificially created without human eggs or embryos). This was the first time in Australia that such research had been carried out,