BIO152H5 Lecture Notes - Lecture 4: Down Syndrome, Dna Replication, Cell Division
Document Summary
Cell division: enables the continuity of life, prokaryotes: cell division results in reproduction. Single circular chromosome, in nucleoid region: dna replication. Cell elongates, splits into two daughter cells. Long, linear dna molecule, carries 100s-1000s of genes. Chromatin = dna + proteins: chromosome number. Attached by cohesions at the centromere: homologous chromosomes. A pair of chromosomes that carry genes for the same characters at corresponding loci: karyotype. Chromosomes of a cell arranged in pairs and organized by length, shape, position of centromere, banding pattern. Mitosis: m: prophase, prometaphase, metaphase, anaphase, telophase. Result: identical nuclei: cell cycle control system. Consists of molecules in the cell that trigger and coordinate events in the cell cycle. Purpose: to prevent the division of cells that are damaged. G1, g2, m: cell cycle regulatory molecules. Provide go signals at g1 and g2 checkpoints. To activate, kinase must attach to cdk (cyclin dependent kinase)
