Download The Cell Cycle

Name ________________________________
Date __________________ Period ________
5.1 – The Cell Cycle
Key Concept: Cells have distinct phases of growth, reproduction, and normal functions.
The cell cycle has 4 main stages.
-The cell cycle is a regular pattern of growth, DNA replication, and cell division.
Cells divide at different rates.
The rate of cell division varies ____________
____________________________________
Some cells are unlikely to divide
-Example: _________________________
Cell size is limited.
 Cell volume increases faster than
surface area.
o Cells need to stay ______ to
allow diffusion and osmosis to work
efficiently.
 Surface area must allow for adequate
exchange of materials.
Cells that must be large have unique shapes (i.e. neurons)
5.2 – Mitosis & Cytokinesis
Key Concept: Cells divide during mitosis and
cytokinesis into
two new daughter cells.
Chromosomes condense at the start of mitosis.
-Chromosomes: carry genetic information (DNA)
that is passed from one generation of ________ to the
next.
-DNA wraps around proteins (_____________________) that condense it
Chromosome Structure

Chromatin:

Chromatid:

Centromere:

Telomere:
Mitosis and cytokinesis produce 2 genetically identical daughter cells.
1. Interphase: Prepares the cell to ______________. DNA is _______________. Includes G1,
S, and G2.
Mitosis divides the cell’s nucleus is 4 phases (PMAT)
2. Prophase – Longest phase of mitosis. Chromosomes __________, spindle fibers form,
nuclear membrane _____________.
3. Metaphase: Chromosomes line up _________________. (Remember M for MIDDLE!)
4. Anaphase: Sister chromatids are ____________________ to opposite sides of the cell.
5. Telophase: Two nuclei form at opposite ends of the cell, nuclear membrane ___________,
chromosomes uncoil back into chromatin.
6. Cytokinesis: Cytoplasm separates. Animal cells: membrane ________ the 2 new cells apart.
Plant cells: cell plate separates 2 new cells.
5.3 – Regulation of the Cell Cycle
Key Concept: Cell cycle regulation is necessary for healthy growth.
Internal and external factors regulate cell division.
External Factors – Come from outside cell
-Include physical and chemical signals
*Cell to cell contact: _____________________
________________________________________.
*Growth factors: chemical signals released by
the cell to tell other cells to grow
-Trigger internal factors which affect the cell cycle
Internal Factors - Come from inside cell
Kinases: enzymes in cells
Cyclins: proteins in cells
*Both help to advance a cell to different
parts of the cell cycle
What happens when the cell cycle isn’t regulated properly?
Cancer cells form
______________________________________________.
May form
Tumors
Malignant
May be
killed by
Apoptosis
Benign
Examples of apoptosis in
healthy organisms:
Cancer cells do not carry out normal cell functions. They come from normal cells with
damage to genes involved in cell-cycle regulation.
Carcinogens are _______________________________________________ (they damage
those genes)
• _____________________________________________________
5.4 – Asexual Reproduction
Key Concept: Many organisms reproduce by cell division.
Binary fission is similar to mitosis.
-Asexual reproduction is the
______________________________________________________
-Binary fission produces
______________________________________________________
-Binary fission occurs in ____________________________
Environment determines which form of reproduction is most
advantageous.
-Asexual reproduction is an advantage in _______________________________________________________
-Sexual reproduction is an advantage in ________________________________________________________
Some eukaryotes reproduce by mitosis.
-______________________________ (example: yeast, hydra)
-______________________________ (example: sea stars)
-______________________________ (example: plants)
5.5 – Multicellular Life
Key Concept: Cells work together to carry out complex functions.
Multicellular organisms depend on interactions among different cell types.
-Tissues are
___________________________________________________________________________
-Organs are
___________________________________________________________________________
-Organ systems are
________________________________________________________________________
Specialized cells perform specific functions.
-Cells develop into their mature forms through the process of
______________________________________.
-Cells differ because
____________________________________________________________ are expressed.
-A cell’s ___________________________ helps determine how it will differentiate.