BIOL 465 Lecture Notes - Lecture 23: Tumor Suppressor Gene, Sister Chromatids, Phosphodiester Bond
31 Jul 2017
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An allele can exist in dominant,recessive or neutral form. 8th jan p53 gene is the tumor suppressor gene. Increase apoptosis if the rst two mechanisms fail to happen the third one will occur. Mitosis: at mitosis the centromere tears into half and we end up getting daughter cells. After mitosis the cells maintain same chromosome number but each will have one chromatid. Meiosis: synapsis occurs. the sister chromatids stay together but the homologous chromosomes separate. crossing over occurs only in meiosis. Pachynema: crossing over is observed here,they exchange genetic material. Diplonema-chiasma is the protein that hold the chromosomes. Phosphodiester bond is broken endonuclease during crossing over- Introduction of p53 gene by double strand breaks leads to the synthesis of the p53 protein,which functions as a transcription factor. Activate genes that arrest cell division and repress the genes that are required for cell division. Sister chromatids separate and become 4 daughter cells.
