Upload
morse
View
50
Download
4
Tags:
Embed Size (px)
DESCRIPTION
The Cell Cycle & Mitosis. Cellular Division 101. The Cell Cycle. The Cell Cycle. The cell cycle is the series of events that occur in a cell including growth, replication and division. There are two major divisions: Interphase Mitotic Phase (Mitosis and Cytokinesis). Interphase. - PowerPoint PPT Presentation
Citation preview
The Cell Cycle & Mitosis
Cellular Division 101
The Cell Cycle
The Cell Cycle The cell cycle is the series of events that
occur in a cell including growth, replication and division.
There are two major divisions: Interphase Mitotic Phase (Mitosis and Cytokinesis)
Interphase
Interphase Interphase is where cells spend most of their
lives. Interphase is the time between cell divisions. There are three phases to Interphase.
G1 – Cell growth S – DNA is copied G2 – Growth continues and preparation for division
begins.
What is Mitosis?
What is Mitosis? Mitosis is the division of the nucleus of a cell
with duplicated DNA In mitosis, a parent cell divides into two
diploid daughter cells Four steps: Prophase, Metaphase,
Anaphase, Telophase
Prophase
Prophase
Chromatin condenses to form chromosomes
Nuclear envelope dissolves Centrosomes move to opposite ends of
the cell Spindle forms between centrosomes
and chromosomes start to move to the center
Metaphase
Metaphase
Chromosomes line up across the center of the cell
Chromosomes attach to the spindle fibers
Anaphase
Anaphase Centromeres divide Sister chromatids move rapidly to opposite
poles
Telophase
Telophase Chromosomes return to chromatin form Spindle fibers disappear Nuclear envelope begins to form around each
set of chromosomes
Cytokinesis
Cytokinesis The process by which cells divide.
Animal cells: cleavage furrow. Area of the cell membrane pinches in
Plant cells: cell plate. Vesicles from the Golgi apparatus join together at the
midline of the cell to form a cell wall
Two daughter cells are about the same size. Each receives half the cytoplasm and half the
organelles.
Prophase
Metaphase
Anaphase
Telophase
Control of Cell Division
Control of Cell Division Think traffic lights – green means go, while red means
stop. Three checkpoints in the cell decide whether the cell should
“stop” or “go”. Cell Growth Checkpoint (G1)
Is the cell large enough? Is it healthy? Green light sends us into DNA replication.
DNA Synthesis Checkpoint (G2) Did DNA replicate correctly? Green sends the cell into
Mitosis. Mitosis Checkpoint
Did mitosis go okay? Green sends the cells exiting mitosis.