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.
Archaebacteria are organisms that are actually very different biochemically and genetically from other bacteria. Hence, archaebacteria is an outdated term, and they are now classified in the Archaea domain. Classifications within this domain are unofficial due to debates over the descendancy of microbes.ydrothermal Vent Archaea. One example in the Archaea domain is Methanocaldococcus jannaschii, currently classified as Archaea: Euryarchaeota: Methanobacteria; Methanobacteriales: Methanobacteriaceae, Methanocaldococcus, and species jannaschii.