Process of Cell Division

Chromosomes Chromosomes: Packages of bundled DNA Chromosomes allow cells to handle such a large molecule like DNA

Prokaryotic Chromosomes Most prokaryotes contain a single, circular DNA chromosome within their cytoplasm.

Eukaryotic Chromosomes Eukaryotic cells generally have more DNA than prokaryotes, therefore contain more chromosomes Ex: Fruit flies have 8 and Humans have 46 Chromosomes make it possible to separate DNA precisely during cell division

Eukaryotic Chromosomes

The Cell Cycle Cell Cycle: series of events as a cell grows and divides Cell grows, prepares for division, and divides to form two daughter cells

Prokaryotic Cell Cycle DNA is replicated once the cell reaches a certain size Binary fission Once chromosome is copied, each copy attaches to a different part of the cell membrane Fibers form between chromosomes Cell is pinched and two new cells are formed

Eukaryotic Cell Cycle Interphase G1 Phase- Cell Growth: cells increase in size and make new proteins and organelles G stands for gap

Eukaryotic Cell Cycle Interphase S Phase- DNA Replication: New DNA is made. At the end of the S phase, the cell will have twice as much DNA as it started with S stands for synthesis Ex: 46 chromosomes doubles to 92

Eukaryotic Cell Cycle Interphase G2 Phase- many of the organelles and molecules required for cell division are produced Shortest phase

Eukaryotic Cell Cycle Mitosis: division of the cell nucleus Prophase: genetic material inside nucleus condenses and the duplicated chromosomes become visible. Outside the nucleus, the spindle starts to form Centromere: area where DNA molecules are attached Sister Chromatids: identical chromosomes Centrioles: organelle that creates spindle fibers

Eukaryotic Cell Cycle Mitosis Metaphase: the centromeres of the duplicated chromosomes line up across the center of the cell. Spindle fibers connect the centromere of each chromosome to the two poles of the spindle. Think of meta and middle

Eukaryotic Cell Cycle Mitosis Anaphase: the chromosomes separate and move along spindle fibers to opposite ends of the cell

Eukaryotic Cell Cycle Mitosis Telophase: the chromosomes, which were distinct and condensed, begin to spread out into a tangle of chromatin. This is the last phase of mitosis and there is still only one cell

Eukaryotic Cell Cycle Cytokinesis Animal cells: cell membrane is drawn inward until the cytoplasm is pinched into two nearly equal parts Plant cells: cell plate forms forms halfway between divided nuclei

Interphase Prophase Metaphase Anaphase Telophase/Cytokinesis