[ppt]the cell cyclemrspbiology.wikispaces.com/file/view/the+cell+cycle... · web viewthe cell cycle...
TRANSCRIPT
The Cell Cycle
The Cell Cycle
copyright cmassengale
1
1
Five Phases of the Cell Cycle
G1 - primary growth phase
S synthesis; DNA replicated
G2 - secondary growth phase
collectively these 3 stages are called interphase
M - mitosis
C - cytokinesis
copyright cmassengale
2
2
Cell Cycle
copyright cmassengale
3
3
Interphase - G1 Stage
1st growth stage after cell division
Cells mature by making more cytoplasm & organelles
Cell carries on its normal metabolic activities
copyright cmassengale
4
4
Interphase S Stage
Synthesis stage
DNA is copied or replicated
copyright cmassengale
5
Two identical copies of DNA
Original DNA
5
Interphase G2 Stage
2nd Growth Stage
Occurs after DNA has been copied
All cell structures needed for division are made (e.g. centrioles)
Both organelles & proteins are synthesized
copyright cmassengale
6
6
Whats Happening in Interphase?
copyright cmassengale
7
What the cell looks like
Animal Cell
Whats occurring
7
Sketch the Cell Cycle
copyright cmassengale
8
Daughter Cells
DNA Copied
Cells Mature
Cells prepare for Division
Cell Divides into Identical cells
8
Mitosis
copyright cmassengale
9
9
Mitosis
Division of the nucleus
Also called karyokinesis
Only occurs in eukaryotes
Has four stages
Doesnt occur in some cells such as brain cells
copyright cmassengale
10
10
Four Mitotic Stages
Prophase
Metaphase
Anaphase
Telophase
copyright cmassengale
11
11
Early Prophase
Chromatin in nucleus condenses to form visible chromosomes
Mitotic spindle forms from fibers in cytoskeleton or centrioles (animal)
copyright cmassengale
12
Chromosomes
Nucleolus
Cytoplasm
Nuclear Membrane
12
Late Prophase
Nuclear membrane & nucleolus are broken down
Chromosomes continue condensing & are clearly visible
Spindle fibers called kinetochores attach to the centromere of each chromosome
Spindle finishes forming between the poles of the cell
copyright cmassengale
13
13
Late Prophase
copyright cmassengale
14
Nucleus & Nucleolus have disintegrated
Chromosomes
14
Spindle Fiber attached to Chromosome
copyright cmassengale
15
Kinetochore Fiber
Chromosome
15
Review of Prophase
copyright cmassengale
16
What the cell looks like
Whats happening
16
Spindle Fibers
The mitotic spindle form from the microtubules in plants and centrioles in animal cells
Polar fibers extend from one pole of the cell to the opposite pole
Kinetochore fibers extend from the pole to the centromere of the chromosome to which they attach
Asters are short fibers radiating from centrioles
copyright cmassengale
17
17
Sketch The Spindle
copyright cmassengale
18
18
Metaphase
Chromosomes, attached to the kinetochore fibers, move to the center of the cell
Chromosomes are now lined up at the equator
copyright cmassengale
19
Pole of the Cell
Equator of Cell
19
Metaphase
copyright cmassengale
20
Chromosomes lined at the Equator
Asters at the poles
Spindle Fibers
20
Metaphase
copyright cmassengale
21
Aster
Chromosomes at Equator
21
Review of Metaphase
copyright cmassengale
22
What the cell looks like
Whats occurring
22
Anaphase
Occurs rapidly
Sister chromatids are pulled apart to opposite poles of the cell by kinetochore fibers
copyright cmassengale
23
23
Anaphase
copyright cmassengale
24
Sister Chromatids being separated
24
Anaphase Review
copyright cmassengale
25
What the cell looks like
Whats occurring
25
Telophase
Sister chromatids at opposite poles
Spindle disassembles
Nuclear envelope forms around each set of sister chromatids
Nucleolus reappears
CYTOKINESIS occurs
Chromosomes reappear as chromatin
copyright cmassengale
26
26
Comparison of Anaphase & Telophase
copyright cmassengale
27
27
Cytokinesis
Means division of the cytoplasm
Division of cell into two, identical halves called daughter cells
In plant cells, cell plate forms at the equator to divide cell
In animal cells, cleavage furrow forms to split cell
copyright cmassengale
28
28
Cytokinesis
copyright cmassengale
29
Cleavage furrow in animal cell
Cell plate in plant cell
29
Mitotic Stages
copyright cmassengale
30
30
Daughter Cells of Mitosis
Have the same number of chromosomes as each other and as the parent cell from which they were formed
Identical to each other, but smaller than parent cell
Must grow in size to become mature cells (G1 of Interphase)
copyright cmassengale
31
31
Identical Daughter Cells
copyright cmassengale
32
Chromosome number the same, but cells smaller than parent cell
What is the 2n or diploid number?
2
32
Review of Mitosis
copyright cmassengale
33
33
Draw & Learn these Stages
copyright cmassengale
34
34
Draw & Learn these Stages
copyright cmassengale
35
35
Name the Mitotic Stages:
copyright cmassengale
36
Interphase
Prophase
Metaphase
Anaphase
Telophase
Name this?
Name this?
36
Eukaryotic Cell Division
Used for growth and repair
Produce two new cells identical to the original cell
Cells are diploid (2n)
copyright cmassengale
37
Chromosomes during Metaphase of mitosis
Prophase
Metaphase
Anaphase
Telophase
Cytokinesis
37
Mitosis Animation
copyright cmassengale
38
Name each stage as you see it occur?
38
Mitosis in Onion Root Tips
copyright cmassengale
39
Do you see any stages of mitosis?
39
Test Yourself over Mitosis
copyright cmassengale
40
40
Mitosis Quiz
copyright cmassengale
41
41
Mitosis Quiz
copyright cmassengale
42
42
Name the Stages of Mitosis:
copyright cmassengale
43
Interphase
Early prophase
Mid-Prophase
Late Prophase
Metaphase
Late Anaphase
Early Anaphase
Early Telophase,
Begin cytokinesis
Late telophase,
Advanced cytokinesis
43
Identify the Stages
copyright cmassengale
44
Early, Middle, & Late Prophase
Late Prophase
Metaphase
Anaphase
Late Anaphase
Telophase
Telophase & Cytokinesis
?
?
?
?
?
?
?
44
Locate the Four Mitotic Stages in Plants
copyright cmassengale
45
Metaphase
Prophase
Anaphase
Telophase
45
Uncontrolled Mitosis
If mitosis is not controlled, unlimited cell division occurs causing cancerous tumors
Oncogenes are special proteins that increase the chance that a normal cell develops into a tumor cell
copyright cmassengale
46
Cancer cells
46