2.31&2.32 Lesson: Cell division and the Cell Cycle

2.31 Cell Division & 2.32 Cell Cycle

Mr. Reed

Learning Objective

• I can summarize the functions of cell division

• I can identify the events that take place during the three stages of the cell cycle.

Cell Division Allow...

• grow

• repair damaged structures

• reproduce

Cell Cycle

During the cell cycle the, a cell growns, prepares for division into two new cells, which are called daughter cells

Interphase

The cell grows, copies DNA, and prepares for Division. Please read G1 (Gap 1)-S (Synthesis)-G2 (Gap 2)

Mitosis

• The division of the nucleus

• Occurs in 4 steps

Cytokinesis

The last step, be sure to look for the cleavage furrow!

Please Remember!

• PMAT = Mitosis

• IPAMATC = Entire Cell cycle

This cell is going through prophase of mitosis.

In prophase, the nuclear membrane breaks down to allow the duplicated chromosomes to spill out into the cytoplasm. Spindle fibers also begin to grow. These structures will be needed later to move the sister chromatids to different places in the cell.

This cell is going through metaphase of mitosis.

During metaphase, the duplicated chromosomes line up along the middle of the cell and the spindle fibers attach to their centromeres.

This cell is going through anaphase of mitosis.

In anaphase, the spindle fibers begin to shorten, pulling the sister chromatids away from one another to opposite sides of the cell.

This cell is in telophase of mitosis.

In telophase, the sister chromatids have been separated and the cell creates a new nuclear membrane around each set of DNA. At this point, the spindle fibers are no longer needed, so they break down.

This cell is in the final step of the cell cycle, called cytokinesis.

During cytokinesis, the cell membrane of the cell pinches in on itself. This causes the cytoplasm and other cell parts to be evenly distributed into two new, identical cells. These new cells are called daughter cells.

The Cell Cycle

• Interphase

• Mitosis

• Cytokinesis

Interphase

Growth and Preparation

3 Parts of Interphase

• G1

• S-Phase

• G2

What happens during each phase of interphase?

• The cell doubles in size during G1

• An exact copy of DNA is made during the S-Phase

• Needed parts are made during the final stage of G2