BILD 1 Chapter Notes - Chapter 9: Cleavage Furrow, Sister Chromatids, Spindle Apparatus
Document Summary
Chromosomes: dna molecules are packaged into these structures. Chromatin: entire complex of dna and proteins that is the building material of chromosomes. Somatic cells: all cells beside sperm and egg. Sister chromatids: joined copies of the original chromosome. Initially attached along lengths by cohesins: protein complexes; sister chromatid cohesion: attachment of cohesins. Centromere: region of the chromosomal dna where the chromatid is attached most closely to its sister chromatid, gives chromosomes a narrow waist . Once sister chromatids separate, considered as individual chromosomes. Mitosis: division of genetic material in the nucleus. Cytokinesis: division of cytoplasm, formation of cleavage furrow pinches the cell in 2. Cleavage furrow: a shallow groove in the cell surface near the old metaphase plate, not present in plant cells. Prophase: chromatin fibers become more tightly coiled, nucleoli disappears, each duplicated chromosome appears as 2 identical sister chromatids joined at centromeres, mitotic spindle forms, centrosomes move away from each other.