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 are unicellular prokaryotes which make them bacteria-like organisms. Their DNA structure resembles the DNA of eukaryotic cells. Also, the cell walls of Archaebacteria are structurally different from the bacterial ones.Archaea live in environments that would not be suitable for most life forms.They can be found around hot geysers, volcanic vents, very salty lakes and on the ocean floor.heir DNA structure resembles the DNA of eukaryotic cells. Also, the cell walls of Archaebacteria are structurally different from the bacterial ones. Archaea live in environments that would not be suitable for most life forms. They can be found around hot geysers, volcanic vents, very salty lakes and on the ocean floor.