prentice hall biology · 2012-08-04 · end of section . title: prentice hall biology author: anita...
TRANSCRIPT
End Show
Slide
1 of 38
Copyright Pearson Prentice Hall
Prentice Hall
Biology
End Show
Slide
2 of 38
Copyright Pearson Prentice Hall
10-2 Cell Division
End Show
10-2 Cell Division
Slide
3 of 38
Copyright Pearson Prentice Hall
In eukaryotes, cell division occurs in two major
stages.
The first stage, division of the cell nucleus, is
called mitosis.
The second stage, division of the cell cytoplasm, is
called cytokinesis.
Cell Division
End Show
10-2 Cell Division
Slide
4 of 38
Copyright Pearson Prentice Hall
Chromosomes
Chromosomes
Genetic information is passed from one
generation to the next on chromosomes.
Before cell division, each chromosome is
duplicated, or copied.
End Show
10-2 Cell Division
Slide
5 of 38
Copyright Pearson Prentice Hall
Chromosomes
Each chromosome consists of two identical “sister” chromatids.
Each pair of chromatids is attached at an area called the centromere.
Sister chromatids
Centromere
End Show
10-2 Cell Division
Slide
6 of 38
Copyright Pearson Prentice Hall
Chromosomes
When the cell divides, the chromatids separate.
Each new cell gets one chromatid.
End Show
10-2 Cell Division
Slide
7 of 38
Copyright Pearson Prentice Hall
The Cell Cycle
What are the main events of the cell
cycle?
End Show
10-2 Cell Division
Slide
8 of 38
Copyright Pearson Prentice Hall
The Cell Cycle
Cell Cycle
The cell cycle is the series of events that cells go
through as they grow and divide.
Interphase is the period of growth that occurs
between cell divisions.
End Show
10-2 Cell Division
Slide
9 of 38
Copyright Pearson Prentice Hall
The Cell Cycle
During the cell cycle:
• a cell grows
• prepares for division
• divides to form two daughter cells, each
of which begins the cycle again
End Show
10-2 Cell Division
Slide
10 of 38
Copyright Pearson Prentice Hall
The Cell Cycle
The cell cycle consists of four phases:
• G1 (First Gap Phase)
• S Phase
• G2 (Second Gap Phase)
• M Phase
End Show
10-2 Cell Division
Slide
11 of 38
Copyright Pearson Prentice Hall
Events of the Cell Cycle
Events of the Cell Cycle
During G1, the cell
• increases in size
• synthesizes new proteins and organelles
End Show
10-2 Cell Division
Slide
12 of 38
Copyright Pearson Prentice Hall
Events of the Cell Cycle
During the S phase,
• chromosomes are replicated
• DNA synthesis takes place
Once a cell enters the S phase, it usually completes the rest of the cell cycle.
End Show
10-2 Cell Division
Slide
13 of 38
Copyright Pearson Prentice Hall
Events of the Cell Cycle
The G2 Phase (Second Gap Phase)
• organelles and molecules required for cell
division are produced
• Once G2 is complete, the cell is ready to start the
M phase—Mitosis
End Show
10-2 Cell Division
Slide
14 of 38
Copyright Pearson Prentice Hall
Cell Cycle
Events of the Cell Cycle
End Show
10-2 Cell Division
Slide
15 of 38
Copyright Pearson Prentice Hall
Mitosis
What are the four phases of mitosis?
End Show
10-2 Cell Division
Slide
16 of 38
Copyright Pearson Prentice Hall
Mitosis
Mitosis
Biologists divide the events of mitosis
into four phases:
• Prophase
• Metaphase
• Anaphase
• Telophase
End Show
10-2 Cell Division
Slide
17 of 38
Copyright Pearson Prentice Hall
Mitosis
Mitosis
End Show
10-2 Cell Division
Slide
18 of 38
Copyright Pearson Prentice Hall
Section 10-2
Prophase Spindle
forming
Chromosomes
(paired
chromatids) Centromere
Click to Continue
Mitosis
Prophase
End Show
10-2 Cell Division
Slide
19 of 38
Copyright Pearson Prentice Hall
Mitosis
Prophase
Prophase is the first and
longest phase of mitosis.
The centrioles separate
and take up positions on
opposite sides of the
nucleus.
Spindle
forming
Centromere Chromosomes
(paired
chromatids)
End Show
10-2 Cell Division
Slide
20 of 38
Copyright Pearson Prentice Hall
Mitosis
The centrioles lie in a region called the centrosome.
The centrosome helps to organize the spindle, a fanlike microtubule structure that helps separate the chromosomes.
Spindle
forming
Centromere Chromosomes
(paired
chromatids)
End Show
10-2 Cell Division
Slide
21 of 38
Copyright Pearson Prentice Hall
Mitosis
Chromatin condenses
into chromosomes.
The centrioles separate
and a spindle begins to
form.
The nuclear envelope
breaks down.
Spindle
forming
Centromere Chromosomes
(paired
chromatids)
End Show
10-2 Cell Division
Slide
22 of 38
Copyright Pearson Prentice Hall
Centriole
Centriole
Spindle
Mitosis
Click to Continue
Metaphase
Metaphase
End Show
10-2 Cell Division
Slide
23 of 38
Copyright Pearson Prentice Hall
Mitosis
Metaphase
The second phase of mitosis is metaphase.
The chromosomes line up across the center of the cell.
Microtubules connect the centromere of each chromosome to the poles of the spindle.
Centriole
Spindle
End Show
10-2 Cell Division
Slide
24 of 38
Copyright Pearson Prentice Hall
Individual
chromosomes
Anaphase
Mitosis
Anaphase
End Show
10-2 Cell Division
Slide
25 of 38
Copyright Pearson Prentice Hall
Mitosis
Anaphase
Anaphase is the third phase of mitosis.
The sister chromatids separate into individual chromosomes.
The chromosomes continue to move until they have separated into two groups.
Individual
chromosomes
End Show
10-2 Cell Division
Slide
26 of 38
Copyright Pearson Prentice Hall
Nuclear
envelope
reforming
Telophase
Mitosis
Telophase
End Show
10-2 Cell Division
Slide
27 of 38
Copyright Pearson Prentice Hall
Mitosis
Telophase
Telophase is the
fourth and final phase
of mitosis.
Chromosomes gather
at opposite ends of the
cell and lose their
distinct shape.
End Show
10-2 Cell Division
Slide
28 of 38
Copyright Pearson Prentice Hall
Mitosis
A new nuclear envelope
forms around each cluster
of chromosomes.
End Show
10-2 Cell Division
Slide
29 of 38
Copyright Pearson Prentice Hall
Cytokinesis
Cytokinesis
Cytokinesis
End Show
10-2 Cell Division
Slide
30 of 38
Copyright Pearson Prentice Hall
Cytokinesis
During cytokinesis, the
cytoplasm pinches in
half.
Each daughter cell has
an identical set of
duplicate chromosomes
End Show
10-2 Cell Division
Slide
31 of 38
Copyright Pearson Prentice Hall
Cytokinesis in Plants
In plants, a structure known as the cell plate forms
midway between the divided nuclei.
Cell wall Cell plate
End Show
10-2 Cell Division
Slide
32 of 38
Copyright Pearson Prentice Hall
Cytokinesis in Plants
The cell plate gradually develops into a separating
membrane.
A cell wall then begins to appear in the cell plate.
End Show
- or -
Continue to: Click to Launch:
Slide
33 of 38
Copyright Pearson Prentice Hall
(must have QuickTake software installed on the
computer you are using for this presentation)
- or -
10-2
End Show
Slide
34 of 38
Copyright Pearson Prentice Hall
10-2
The series of events that cells go through as
they grow and divide is called
a. the cell cycle.
b. mitosis.
c. interphase.
d. cytokinesis.
End Show
Slide
35 of 38
Copyright Pearson Prentice Hall
10-2
The phase of mitosis during which the
chromosomes line up across the center of the
cell is
a. prophase.
b. metaphase.
c. anaphase.
d. telophase.
End Show
Slide
36 of 38
Copyright Pearson Prentice Hall
10-2
Cytokinesis usually occurs
a. at the same time as telophase.
b. after telophase.
c. during interphase.
d. during anaphase
End Show
Slide
37 of 38
Copyright Pearson Prentice Hall
10-2
DNA replication takes place during the
a. S phase of the cell cycle.
b. G1 phase of the cell cycle.
c. G2 phase of the cell cycle.
d. M phase of the cell cycle.
End Show
Slide
38 of 38
Copyright Pearson Prentice Hall
10-2
During mitosis, “sister” chromatids separate from
one another during
a. telophase.
b. interphase.
c. anaphase.
d. metaphase.
END OF SECTION