Cell Division & Mitosis

Cell Division in Prokaryotes Prokaryotes are Like bacteria are less complex Have a single, circular DNA and ribosomes Divide by Binary Fission

Cell Division in Prokaryotes Asexual reproduction: One parent = 2 offspring Division of prokaryotic cell into two identical offspring cells Cell grows to twice its size Cell membrane pinches off 2 new identical cells form from one parent

Cell Division in Eukaryotes Mitosis Division of the nucleus Occurs in all cells EXCEPT sex cells Cytokinesis Division of the entire cell

Chromosomes A structure found in the nucleus of eukaryotic cells that contains DNA Eukaryotic cells contain more DNA For example fruit flies have 8 chromosomes and humans have 46 chromosomes

Chromosomes Homologous pairs Two sets of chromosomes that carry genes for the same trait So humans have 23 homologous pairs of chromosomes

Cell Cycle Interphase Time between cell divisions 3 phases Cells spend the majority of their life in this stage 3 phases G1 phase: grows and develops S phase: DNA replicates G2 phase: prepares for mitosis

Mitosis: Nuclear Division 1. Prophase Duplicated chromosomes condense to form chromatids Metaphase Chromatids line up in the middle of the cell Anaphase Chromatids separate at the centromere and slowly move to the opposite poles When chromatids separate they are now called chromosomes Telophase Nuclear membrane forms around each set of chromosomes

Mitosis

Cell Division in Eukaryotes Cytokinesis Process of dividing cytoplasm Cleavage of new cell membrane or a cell plate forms to create a cell wall Algae Plants Fungi Process of dividing the cell into 2 different cells In humans, each cell will contain 23 pair of chromosomes A total of 46 chromosomes per cell