BIOL 102 Lecture Notes - Lecture 30: Microtubule, Centromere, Metaphase
Document Summary
New progeny cells are needed to expand population size, multicellular tissue growth, asexual reproduction and replacements of cells lost to wear and tear. If cells divide too quickly, daughter cells may be too small or lack genetic material, etc . If cells divide too slowly, they may grow inefficiently large or accumulate extra chromosomes. A prokaryotic cell must double in size, replicate its circular chromosome, and move each of the resulting daughter chromosomes into its own progeny cell. Prokaryotic cells divide by binary fission, splitting into two parts. B period cells grow for sometime before initiating dna synthesis; b period doesn"t exist when nutrients are abundant and cells grow quicker. C period bacterial chromosome replication commences at the ori in the middle of the cell where enzymes for dna replication are located. The two new replicated oris move toward the opposite poles of the cell.
