Mitosis & the Cell Cycle

12/10/2012

Goals for the Day

• See what we need to review for the

semester test!

• Be able to define what the cell cycle is

• Be able to define what mitosis is, and what its

purpose is

• Be able to describe the phases of mitosis

(nuclear division)

Cell Cycle

• Purpose of the cell cycle

to reproduce, repair, & replace cells.

Cell Division• Before Eukaryotic Cells divide they need

to first replicate their control center, so that each new cell has one.

• In Eukaryotic cells that control center is known as the ____________.

• I say Eu, you say_______• I say Pro, you say _______

Cell Division

• Before the control center divides it must replicate its most important feature, the _______ which is housed in the nucleus of eukaryotes.

Cell Cycle

• Interphase – where a cell spends the majority of its life (over 90%)

Goals for the Day

• See what we need to review for the

semester test!

• Be able to define what the cell cycle is

• Be able to define what mitosis is, and what its

purpose is

• Be able to describe the phases of mitosis

(nuclear division)

Question of the Day

• In What phase of the cell cycle does a cell

spend most of its life (more then 90%)?

Cell Cycle

• Interphase – where a cell spends the majority of its life (over 90%)

5 Phases of the cell cycle

1. First growth (G1) phase cell grows rapidly and carries out its routine functions.

2. Synthesis (S) phase A cell’s DNA is copied

3. Second growth (G2) phase prepares for the nucleus to divide.

4. Mitosis the nucleus of a cell is divided into two

5. Cytokinesis the cytoplasm divides

Cell Cycle• The purpose of cell division is to

reproduce cells.

• Sometimes cells are not controlled by these genes & proteins

• Uncontrolled growth = Cancer

Cell Cycle

• Mitosis – can be divided into 5 basic parts

• Prophase• Metaphase• Anaphase• Telophase

– Cytokinesis

Mitosis – Cell Division (Cell Reproduction)

Mitosis PhasesInterphase – This is where a cell spends a majority of its life.

Nucleus Cell

Membrane

Chromatin

Prophase –Centrioles and Spindle Fibers start to appear

Chromosomes become visible

Nuclear Membrane disappears

Metaphase –

Chromosomes line up in the middle of the cell

(“meta” means middle)

Centrioles

Spindle Fibers

Chromosomes

Anaphase –

Spindle fibers separate the chromatids and pull them to opposite ends of the cell.

Centriole

Spindle Fibers

Chromatids

Telophase –

Cell membrane starts to pinch in the middle

Two new nuclei start to form in each new cell

Chromosomes disappear into the nucleus

Cytokinesis – the dividing up of the cytoplasm

Chromosomes Nuclei

Cell Membrane

Newt Lung Cell Mitosis

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