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.
The Archaea (/ÉËrËkiËÉ/ or /ÉËrËkeÉªÉ/ ar-KEE-É or ar-KAY-É) constitute a domain and kingdom of single-celled microorganisms. These microbes (archaea; singular archaeon) are prokaryotes, meaning they have no cell nucleus or any other membrane-bound organelles in their cells. Archaea were initially classified as bacteria, receiving the name archaebacteria (in the Archaebacteria kingdom), but this classification is outdated.