2-1 Notes – Cell Cycle & Cell Division
Prophase
Metaphase
Anaphase
Telophase
 Mitosis and cell division produce most cells in a _________-celled organism .
 Mitosis has ____ phases: Prophase, Metaphase, Anaphase, Telophase
 Prophase – DNA in _____________________ twists into tight coils and the
___________ breaks apart.
 Metaphase – The chromosomes move to the ___________ of the cell and pairs of sister
_____________ line up.
 Anaphase – Fibers attached to the ______________ of the sister chromatids pull them
apart toward opposite ends of the cell, and the cell _______________ out.
 Telophase – A new ______________ forms around each set of chromosomes , creating
two identical nuclei, and __________________ become less tightly coiled.
Interphase
Cell Cycle
 The ________ ___________ is the life cycle of the _______ .
 One “parent” cell divides to form two _________________ “______________” cells.
 Stages of the cell cycle include: ______________ , ____________ , _______________
 During Interphase, a cell _________________ to reproduce.
 During Mitosis, the ________________ divides.
 During Cytokinesis, the ____________________ divides, producing ______ new cells.
 The length of time for the cycle differs for different organisms and _______ .
 Cell cycles repeat quickly in _________ stages of ________________ growth.
1. Interphase
 ___________________ takes the longest, and has 3 phases: ____ , ____ , ____
 ____ phase:
o The cell ___________ and carries out normal ____________________ .
o Some cells (muscles, nerve , red blood cells) stay in G1 and never ______________
 ____ phase:
o Each pair of similar chromosomes is called a pair of _________________
chromosomes .
o Homologous chromosome pairs in the cell’s __________ replicate.
o These copies of the chromosomes are called sister ___________ .
o Replication ensures that the _____ cells formed are ___________ .
 ____ phase:
o The cell _______ , functions, and some _______________ replicate
2. Mitosis
 Mitosis is the process by which the ____________ divides.
 Mitosis and cell ______________ ensure that each ______ cell receives all it needs to
______________ .
 Mitosis and cell division replace _____ worn-out cells, and are the method of
________________ for some organisms.
p. 101
Cytokinesis
3. Cytokinesis
 The _____________ and its contents divide to form two identical _____________ cells.
 At the start, the cell ______________ pinches inward.
 In a cell with a _____ _______ , a _______ ________ forms between the two nuclei.
 The cell plate later becomes the cell _______________ , which builds the new cell walls.
Cell Division
• Results in two new ______________ cells to replace the original ____________ cell.
• Each ________________ cell has the exact same _______________ and ________ of ____________________ as
the _____________ cell.
• All the cells in your body (except _____ and _______ ) have ___________ chromosomes.
Cell Cycle
Phase
Stages
Description
Growth and cellular functions
Interphase
Growth and chromosome replication
Growth and cellular functions; organelle replication
Mitotic
Phase
Nucleus divides
Cytoplasm divides
Review
____ 1. When a cell is preparing to reproduce, what phase of the cell cycle is it in?
A. S phase
C. interphase
B. prophase
D. mitosis
____ 2. In which phase does the nucleus divide?
A. G2
C. cytokinesis
B. mitosis
D. cell division
____ 3. In which type of cell would you expect to see a cell plate form?
A. plant cell
C. stomach cell
B. animal cell
D. parent cell
____ 4. Each chromosome in one set of chromosomes has a similar chromosome in the other set of chromosomes. What
is a pair of similar chromosomes called?
A. sister chromosomes
C. daughter chromosomes
B. homologous chromosomes
D. parent chromosomes
____ 5. Sister chromatids are held together at what region of the chromatids?
A. the ends
C. the cell plate
B. the centromere
D. G1
____ 6. When do the sister chromatids of each replicated chromosome begin to separate?
A. prophase
C. anaphase
B. metaphase
D. telophase
____ 7. What happens during cytokinesis?
A. the nucleus divides
C. chromosomes are replicated
B. the cytoplasm divides
D. growth and cellular functions
____ 8. What is the first phase of mitosis?
A. interphase
C. prophase
B. G1
D. cell division
2-1 Notes – Cell Cycle & Cell Division
Cell Cycle
•
•
•
•
•
•
•
•
The cell cycle is the life cycle of the cell.
One “parent” cell divides to form two identical “daughter” cells.
Stages of the cell cycle include: Interphase, Mitosis, Cytokinesis
During Interphase, a cell prepares to reproduce.
During Mitosis, the nucleus divides.
During Cytokinesis, the cytoplasm divides, producing two new cells.
The length of time for the cycle differs for different organisms and cells.
Cell cycles repeat quickly in early stages of animal growth.
1. Interphase
• Interphase takes the longest, and has 3 phases: G1 , S , G2
•
G1 phase:
•
•
Telophase – A new membrane forms around each set of chromosomes, creating
two identical nuclei, and chromosomes become less tightly coiled.
Telophase
•
apart.
Metaphase – The chromosomes move to the middle of the cell and pairs of sister
chromatids line up.
Anaphase – Fibers attached to the centromere of the sister chromatids pull them
apart toward opposite ends of the cell, and the cell stretches out.
Anaphase
•
Metaphase
the cell grows, functions, and some organelles replicate
2. Mitosis
• Mitosis is the process by which the nucleus divides.
• Mitosis and cell division ensure that each new cell receives all it needs to function.
• Mitosis and cell division replace old worn-out cells, and are the method of
reproduction for some organisms.
• Mitosis and cell division produce most cells in a many-celled organism.
• Mitosis has 4 phases: Prophase, Metaphase, Anaphase, Telophase
• Prophase – DNA in chromosomes twists into tight coils and the nucleus breaks
•
Prophase
•
The cell grows and carries out normal functions.
Some cells (muscle, nerve, red blood cells) stay in G1 and never reproduce.
S phase:
• Each pair of similar chromosomes is called a pair of homologous chromosomes.
• Homologous chromosome pairs in the cell’s nucleus replicate.
• These copies of the chromosomes are called sister chromatids.
• Replication ensures that the new cells formed are identical.
G2 phase:
Interphase
•
•
•
•
•
At the start, the cell membrane pinches inward.
In a cell with a cell wall, a cell plate forms between the two nuclei.
The cell plate later becomes the cell membrane, which builds the new cell walls.
Cell Division
• Results in two new daughter cells to replace the original parent cell.
• Each daughter cell has the exact same number and type of chromosomes as the parent cell.
• All the cells in your body (except egg and sperm) have identical chromosomes.
Cell Cycle
Phase
Interphase
Mitotic
Phase
Stages
G1
S
G2
Mitosis
Cytokinesis
Cytokinesis
3. Cytokinesis
• The cytoplasm and its contents divide to form two identical daughter cells.
Description
Growth and cellular functions
Growth and chromosome replication
Growth and cellular functions; organelle replication
Nucleus divides
Cytoplasm divides
Review (Answers: 1-C, 2-B, 3-A, 4-B, 5-B, 6-C, 7-B, 8-C)
____ 1. When a cell is preparing to reproduce, what phase of the cell cycle is it in?
A.
S phase
C.
interphase
B.
prophase
D.
mitosis
____ 2. In which phase does the nucleus divide?
A.
G2
B.
mitosis
C.
D.
cytokinesis
cell division
____ 3. In which type of cell would you expect to see a cell plate form?
A.
plant cell
B.
animal cell
C.
D.
stomach cell
parent cell
____ 4. Each chromosome in one set of chromosomes has a similar chromosome in the other set of chromosomes. What
is a pair of similar chromosomes called?
A.
sister chromosomes
C.
daughter chromosomes
B.
homologous chromosomes
D.
parent chromosomes
____ 5. Sister chromatids are held together at what region of the chromatids?
A.
the ends
C.
B.
the centromere
D.
the cell plate
G1
____ 6. When do the sister chromatids of each replicated chromosome begin to separate?
A.
prophase
C.
anaphase
B.
metaphase
D.
telophase
____ 7. What happens during cytokinesis?
A.
the nucleus divides
B.
the cytoplasm divides
C.
D.
chromosomes are replicated
growth and cellular functions
____ 8. What is the first phase of mitosis?
A.
interphase
B.
G1
C.
D.
prophase
cell division