9 cell cycle-mitosis

Cell Cycle - Mitosis

How do you grow?How do cells make more cells?You grow in size by making more cells.From a baby to adult you add more cells to

your bodyWhere do the new cells come from?Remember the Cell Theory (#3):

“Cells come from preexisting cells”Cells divide to make new cellsThis process is called Cell Division

Cell DivisionWhen you grow your cells divideCells increase as you grow.Cells reproduce, make new cells by dividing

Cells Make New Cells by DividingCell division: making new cells.Inside the nucleus are chromosomesEvery cell needs to have a copy of all

chromosomes Before a cell divides, chromosomes

have to make copies of themselves.At the end, daughter cells have the

same number of chromosomes as the parent cell

Cell DivisionThe goal of cell

reproduction is to produce 2 “daughter cells” that are IDENTICAL to the parent cell.

Cells are identical because the chromosomes replicate (copy) before division.

Each daughter cells gets a copy of each chromosome.

This is called Mitosis

Respiration Mitosis

RespirationDivision of the

nucleus

CELL DIVISION: Mitosis + CytokinesisMitosis: Is the division of the nucleus. The chromosomes are copied (replicated) and then split into 2 groups.

Cytokinesis: Is the division (separation) of the Cytoplasm. The cell divides.

Prophase

Metaphase

Anaphase

Telophase

Prophase

Metaphase

Anaphase

Telophase

DNA condenses (coils together) and the chromosomes become visible

Nuclear membrane disappears

Doubled chromosomes get thick and become short

Nuclear membrane disappears

1. ProphaseDouble

chromosomes get thick and become short

Nuclear membrane disappears

Prophase

Metaphase

Anaphase

Telophase

Chromosomes line up in the middle of the cell (equator)

Chromosomes connect to the spindle fibers

2. Metaphase

Chromosomes line up in the middle of the cell (equator)

Prophase

Metaphase

Anaphase

Telophase

Chromosomes copy, split, and separate

3. Anaphase

Chromosomes

copy, split, and

separate

Prophase

Metaphase

Anaphase

Telophase

Nuclear membrane forms. Cell begins to split

4. TelophaseNuclear membrane forms againCell begins to split in half

Cell Division in PlantsJust like animal cells, plant cells reproduce

through cell division but they do not make the same kind of daughter cells. In plant cells a cell plate forms instead of a cleavage furrow before the cell splits in half. The cell membrane divides the cell, the cell plate becomes the cell wall and two daughter cells form on each side of the wall.

What happens when cells cannot control themselves?

Cells divide and divide.Uncontrolled cell

division causes cancer.Cancer is the

uncontrolled division of body cells.

Cells divide too much and form tumors.

Cells with tumors cannot do their job and “push” out other cells