KEY CONCEPT Cells divide during mitosis and cytokinesis.

Chromosomes condense at the start of mitosis. 1. Chromosomes are made up one long strand of DNA 2. DNA wraps around proteins (histones) and then form chromatin (spaghetti) DNA double helix DNA and histones Chromatin Supercoiled DNA

Chromosomes form and become present during prophase chromatid telomere centromere Condensed, duplicated chromosome Chromosomes form and become present during prophase One half of a duplicated chromosome is a chromatid. Sister chromatids are held together at the centromere.

#1 = INTERPHASE prepares the cell to divide in G1, S, G2 Mitosis and cytokinesis produce two genetically identical daughter cells. Parent cell centrioles spindle fibers centrosome nucleus with DNA #1 = INTERPHASE prepares the cell to divide in G1, S, G2 During interphase, growth occurs and the DNA is duplicated.

Mitosis divides the cell’s nucleus in four phases. #2 PROPHASE, chromosomes condense and spindle fibers form (chromosomes PRESENT)

Mitosis divides the cell’s nucleus in four phases. #3 = METAPHASE, chromosomes line up in the equator of the cell (chromosomes in MIDDLE)

Mitosis divides the cell’s nucleus in four phases. #4 = ANAPHASE, sister chromatids separate to opposite sides of the cell. (chromosomes pull APART)

Mitosis divides the cell’s nucleus in four phases. #5 = TELOPHASE, the new nuclei form and chromosomes begin to uncoil (chromosomes in TWO new cells)

#6 = CYTOKINESIS differs in animal and plant cells. In animal cells, the membrane pinches closed. In plant cells, a cell plate forms. CELL SPLITS INTO 2 CELLS