The Cell Cycle

Here is what we’re going to learn about.

PARENT CELL

2 DAUGHTER CELLS

CELL DIVISION

The Stages of the Cell Cycle

STAGE 1: Interphase

STAGE 2: Mitosis

Prophase

Metaphase

Anaphase

Telophase

STAGE 3: Cytokinesis

NUCLEUS DIVIDES

CELL MEMBRANE DIVIDES

CELL GETS READY

Phase 1: Growing

• The cell GROWS to its full size and produces the structures it needs.

• The cell may make new ribosomes and enzymes and copies are made of mitochondria.

THE CELL LOOKS AND ACTS PRETTY NORMAL IN THIS PHASE

INTERPHASE - Growing

• Cell grows to its normal size

• Cell makes a copy of its DNA (DNA REPLICATION)

• 2 Centrioles are copied to make a total of 4

INTERPHASE

CENTRIOLECENTRIOLE

Phase 2: Copying DNA

• The cell makes an exact copy of the DNA in its nucleus. This process is called DNA REPLICATION.

• Important step, because the new cells (daughter cells) must have an exact copy of the first cell’s (parent cell) DNA.

• After the Copying DNA Phase, 2 identical sets of DNA are in the parent cell.

Phase 2: Copying DNA(occurs inside nucleus)

ORIGINAL

ORIGINAL

COPY

What is Stage 2: Mitosis?

This is the 2nd Stage of the Cell Cycle.

• This is the stage during which the cell’s nucleus divides into 2 new Nuclei. During mitosis, 1 copy of the parent’s DNA is made for each of the 2 daughter cells.

• There are 4 phases in Mitosis: prophase, metaphase, anaphase, and telophase.

MITOSIS:PROPHASE

• Chromatin shrinks to make Chromosomes

• Spindle fibers are formed

• Membrane around nucleus breaks down

MITOSIS: PROPHASE

CHROMOSOME• Made up of 2 chromatids held together by

a centromere.

• Chromatids are made of DNA.

MITOSIS: METAPHASE

• Chromosomes line up in middle of cell

• Spindle fibers grab onto centromeres of chromosomes

MITOSIS: METAPHASE

MITOSIS: ANAPHASE

• Centromeres split

• Spindle fibers pull chromatids to either side of cell

(CYTOKINESIS BEGINS: cell stretches out)

MITOSIS: ANAPHASE

MITOSIS: TELOPHASE

• Chromosomes stretch out and begin to turn back into chromatin

• Nuclei reform(CYTOKINESIS CONTINUES: cell pinches in the middle)

MITOSIS: TELOPHASE

Phase 3: Preparing for Division

• The cell gets ready to divide.

• The cell produces structures that it will use to divide into new cells.

• The cell makes a copy of its 2 centrioles, to now have 4 of them.

• Once this step is over, the cell is ready to divide.

Cytokinesis in an Animal Cell

BEFORE DURING AFTER

• Each daughter cell is given equal organelles and 1 nucleus.

• Cell membrane splits, forming 2 new daughter cells.

ANIMAL CELL: CYTOKINESIS

Cytokinesis in Plant Cells

• A cell plate forms in the middle of the cell. • The cell plate turns into a cell membrane that cuts the cell into 2 daughter cells. • New cell walls then form around each of the daughter cells to protect them..

PLANT CELL: CYTOKINESIS

How long do the 3 stages take?

HUMAN LIVER CELL

HOWLONGDOES THE WHOLETHINGTAKE?