Answer:
Periosteum, dense fibrous membrane covering the surfaces of bones, consisting of an outer fibrous layer and an inner cellular layer (cambium). The outer layer is composed mostly of collagen and contains nerve fibres that cause pain when the tissue is damaged.
Answer: Tomato plant is a multicellular organism.
Explanation: A multicellular is a organism composed by many types of cells or cell lines. A tomato plant is composed not only by million of cells but by many types of them in the different tissues and organs, for example, leaves have epidermic cells that protect them, stomata cells for gas exchange, chlorenchyme cells that have chloroplasts to do photosynthesis, phloem and xylem cells to transport fluids, etc.
completed question'
.....culturing viruses that requires a human host
Answer:
Diploid cell culture lines, developed from human embryos, are widely used for culturing viruses that require a human host
Explanation
Viruses can not thrive in a non-living host or artificial media.They are intracelular parasites which needed living host to replicate . Cultures lines from Human embryo in are therefore used for culturing viruses of human host, so that its mode of replication and gene expression can be studied, and therefore its virulence can easily be studied.
This method have the advantage that;
1.there is no need to make use of the whole animal rather,on a tiny tissue needed can be isolated for culture.
2. the cells growth is continuous,and can be preserved in liquid Nitrogen and renew for future culture
3. cells can be grown in different containers, with ability to decide the number of cells needed.
Temperature is kept at optimum for human in the culture at 37 degree centigrade, nutrients are provided, NaHC03 as buffers for C02, and the medium is humidified.
I wanna say it's sand stone but I'm not sure what you are learning about
