Mitosis What is it? Why is it Important? What do I need to know?

Why more cells? Populations of single-cell critters Multicellularity? We all start out as a single cell…? The zygote… & become/remain multicellular

Binary Fission…Monera

Binary Fission..DNA duplicates…why?

DNA separates & new cell wall divides cell in two

2 ‘new’ cells…identical?

Binary Fission

quiz What happens to the size of bacteria after binary fission? What has to happen before fission occurs? What benefit(s) do bacteria derive from binary fission (as opposed to sexual reproduction)?

Eukaryotic cells?? The nucleus? Nuclear membrane Chromosomes…not chromosome…? All that ‘stuff’ in the cytoplasm?

Eukaryotic cell cycle Cell is ‘born’ Duplicates DNA?? Grows to…size? Prepares to divide Divides=mitosis

The nuclelus must first divide before the cell can Why? How? How much time of the cell cycle/life can be spent in mitosis?

Chromosomes duplicate

Mitosis produces identical offspring (2N---2N)

Why some cells stop mitosis…differentiation Muscle cells… Nerve cells… Critical functions might be disrupted Adaptations to this condition

Importance??? Growth Replacement Regeneration of Tissue

Cancer? Unregulated mitosis Benign Malignant/ metastasis How does it begin?

Mitosis quiz Use two words to describe the importance of mitosis Draw and label the cell cycle…include G1, S, G2, M and cytokinesis…what happens at each stage? What disease is associated with mitosis? Are all organisms limited to 50 mitotic divisions?

Name stage of mitosis

These are bacteria Watch the clip What kind of reproduction is shown here? What advantage does this confer on the organism?

Mitosis Video (click below)