Why a mastectomy may be necessary. A mastectomy is mainly used as a treatment for breast cancer or to reduce the risk of breast cancer developing. Although breast cancer in men is much rarer than female breast cancer, it can also be treated with a mastectomy. Treating breast cancer.
Bacteria. The Bacteria are considered as unicellular prokaryotic organisms. Unlike eukaryotes, bacteria cells lack an organized nucleus, mitochondria, chloroplasts and other membrane bounded organelles. Bacterial cell has only a circular DNA, which does not associate with histone protein.Bacteria do not show sexual reproduction methods.nlike eukaryotes, bacteria cells lack an organized nucleus, mitochondria, chloroplasts and other membrane bounded organelles. Bacterial cell has only a circular DNA, which does not associate with histone protein. Bacteria do not show sexual reproduction methods.
Archaea and bacteria have different cell membranes and cell structures, and archaea are found in extreme environments where most bacteria could not survive. Bacteria cell walls contain a substance known as peptidoglycan, while the cell walls of archaea do not.Archaea and bacteria also differ because the cell membranes of archaea have a unique structure and do not contain the same lipids, or fats, that are found in the cell membranes of other organisms.rchaea and bacteria differ in the environments in which they can survive. While bacteria live almost everywhere, only archaea are capable of surviving in harsh extremes, although they are also found elsewhere. Some archaea, known as thermophiles, live in very hot environments such as volcano vents.