BIS 2A Lecture Notes - Lecture 11: Ftsz, Methyl Group, S Phase
29 Apr 2019
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Changes in gene expression or phenotype that don"t involve changes in the dna sequence. Adding methyl groups to dna sequence, doesn"t change the bases. Ex - neurons, smooth muscle fibers, white blood cells. Replicate the dna, organelles, expand cytoplasm and the membrane, make more ribosomes and enzymes. The steps: environmental signals must be favorable, copy the dna, separate the two copies. Can"t be too small or too large for replication and division to occur. Dna is eukaryotes - histones are homologous to proteins in bacteria. Proteins in bacteria keep dna of bacteria folded neatly. Chromosome segregation: coli genome has only one origin of replication (oric) Two copies of oric segregate to opposite sides of cell. No - there is more than one origin of replication. Multiple origins of replication shred the chromosomes apart as multiple proteins occur. Cell has to check that it has the right 23 chromosomes.
