The Cell Cycle Notes
The cell cycle has six main stages.
•
•
The cell cycle is a regular pattern of ________________________,
________________________________, and ________________________________.
The main stages of the cell cycle are ___________________________ ( with 3 parts),
___________________________ (with two parts), and ___________________.
•
Interphase
– Cells spend the ____________________________of their cell cycle in interphase.
– The purpose of interphase is for _____________________________.
– By the end of interphase a cell has two full sets of DNA (_____________________) and is large
enough to begin the __________________________.
– Interphase is divided into ________________________ phases. Each phase is characterized by
________________processes involving different structures.
o
During
the
G1
(________________)
phase,
the
cell
_______________
and
__________________ proteins.
o
During the S (______________) phase, chromosomes _____________________ and
__________________
to
form
identical
sister
________________________
held
together by a ___________________________.
o
During the G2 (_________________) phase, cells continue to ____________________ and
_______________the ______________________ necessary for cell division
Mitosis
• The purpose of mitosis is ____________________: making _______________ cells out of one.
•
Each cell has to have its own ____________________and ___________________.
• The DNA is ______________________ in Interphase when _______________ chromosome
strands became ________________ strands (two strands per chromatid).
• In mitosis the four strands (_____________________________________) have to break apart so
that each new cell only has one ________________________ chromosome.
•
Mitosis is divided into ________________ phases. Each phase is characterized by specific processes
involving different structures.
__________________is characterized by four events:
1.
Chromosomes ________________ and are more ___________.
2. The nuclear membrane (envelope) _____________.
3. ___________ have _________________ and taken positions on the ___________poles of
the cell.
4. ________________ form and radiate toward the center of the cell.
Metaphase (the shortest phase of mitosis) is characterized by two events:
1.
Chromosomes _________________ across the middle of the cell.
2. Spindle fibers ___________ the centromere of each sister chromatid to the poles of the cell.
Anaphase is characterized by three events:
1.
Centromeres that _______________ the sister chromatids split.
2. Sister chromatids ________________ becoming _________________chromosomes.
3. Separated chromatids ___________ to opposite poles of the cell.
Telophase (the last phase of mitosis) consists of four events:
1.
Chromosomes (each consisting of a single chromatid) _________________.
2. A _________________________ forms around the chromosomes at each pole of the cell.
3. Spindle fibers __________________ and _________________.
4. Cytokinesis begins.
Cytokinesis
•
Cytokinesis is the division of the ______________________ into two individual cells.
•
The process of cytokinesis differs somewhat in plant and animal cells.
In animal cells the cell membrane forms a _____________________ that eventually pinches
the cell into two nearly equal parts, each part containing its own nucleus and cytoplasmic organelles.
In plant cells a structure known as a cell plate forms midway between the divided nuclei, which
gradually develops into a separating membrane. The cell wall forms in the _________________.
Prophase
Metaphase
Anaphase
Telophase