Transcript PowerPoint Chapter 3 Lesson 1 part 1

The Cell Cycle and Cell Division
Chapter 3 Lesson 1 part 1
The Cell Cycle and Cell Division
How can one cell
become a multicellular
organism?
The Cell Cycle and Cell Division
• What are the phases of the
cell cycle?
• Why is the result of the cell
cycle important?
The Cell Cycle
Most cells in an
organism go
through a cycle
of growth,
development,
and division
called the
cell cycle.
The Cell Cycle
Through the
cell cycle,
organisms
grow, develop,
replace old or
damaged cells,
and produce
new cells.
The Cell Cycle
There are two main phases in the cell
cycle—interphase and the mitotic phase.
Interphase
Interphase is the period during the cell cycle
of a cell’s growth and development Most of
the cells life is in interphase. During
interphase, most cells go through 3 stages:
• Rapid growth and replication, or
copying of the membrane-bound
structures called organelles.
• Copying of DNA, the genetic
information in a cell
• Preparation for cell division
Interphase
Interphase occurs in three stages: G1, S, and
G2.
Interphase


G1 phase: The period prior to the synthesis
of DNA. In this phase, the cell increases in
mass in preparation for cell division. Note
that the G in G1 represents gap and the 1
represents first, so the G1 phase is the first
gap phase.
S phase: The period during which DNA is
synthesized. In most cells, there is a narrow
window of time during which DNA is
synthesized. Note that the S represents
synthesis.
Interphase

G2 phase: The period after DNA synthesis
has occurred but prior to the start of cell
division. The cell synthesizes proteins and
continues to increase in size. Note that the
G in G2 represents gap and the 2
represents second, so the G2 phase is the
second gap phase.
Length of a Cell Cycle
The length of the cell cycle varies
depending on the type of cell.