Interactive Notes: pages 10-2 Cell Division Interactive Notes: pages

Chromosomes Made up of DNA (genetic info.) and proteins Each species has it’s own differing number of chromosomes Fruit flies – 8 chromosomes Humans – 46 chromosomes Carrots – 18 chromosomes Duplicated before cell division Become visible during cell division

Parts of a Chromosome Chromatids: 2 identical “sister” sides Centromere: where chromatids attach in the middle Telomere: protective tip or end of chromosomes

The Cell Cycle Events that the cell goes through as it grows and divides into two new daughter cells Interphase- the period of growth between cell divisions Four Phases G1 (First Gap Phase) S Phase G2 (Second Gap Phase) M Phase (Mitosis)

4 Phases of the Cell Cycle G1- cell increases in size and makes new proteins and organelles S- chromosomes are duplicated and DNA is synthesized G2- organelles needed for cell division are made M- mitosis

4 Phases of Mitosis REMEMBER----PMAT Prophase Metaphase Anaphase Telophase

Prophase *Longest (50-60%) *Chromosomes become visible *Centrioles separate & move to opposite sides of the nucleus Spindles form Nuclear envelope breaks down

Metaphase Chromosomes line up across the cell center Microtubules connect centromere to the spindle

Anaphase Centromeres split Sister chromatids separate and become individual chromosomes Chromosomes move toward the poles

Telophase Chromosomes gather at opposite ends of the cell New nuclear envelope forms around chromosomes

Cytokinesis Cytoplasm pinches in half Each daughter cell has an identical set of duplicate chromosomes In plants, a cell plate develops separating the membrane and a cell wall begins to appear

The Cell Cycle results in 2 identical DIPLOID daughter cells

Amoeba Sisters https://www.youtube.com/watch?v=gwcwSZIfKlM Complete worksheet during video