The cell cycle describes the life of a cell and is divided into three main stages: interphase, mitosis, and cytokinesis. During interphase, the cell grows and DNA is replicated. Mitosis involves the duplication and separation of chromosomes, dividing the nucleus. Cytokinesis then splits the cell into two identical daughter cells. The stages of mitosis are prophase, metaphase, anaphase and telophase, during which the chromosomes align and separate. Cytokinesis differs between plant and animal cells, with plant cells forming a cell plate and animal cells pinching together.

1. 5A: CELL CYCLE &
• Ident i fy and descr ibe the main phases
of the cel l cycle
• Ident i fy what form DNA is in dur ing
di f ferent stages of the cel l cycle
• Descr ibe 3 key events dur ing interphase
• Ident i fy and descr ibe 4 main phases of
mi tosis
• Compare cytokinesis in plant and
animals cel ls
5B: MITOSIS

2. THE CELL CYCLE
 The l ife of a cel l is described as the cel l cycle.
 Divided into three stages:
 INTERPHASE: Cells carry out normal functions
 MITOSIS: Duplication of genetic material and division of the nucleus
 CYTOKINESIS: Cell with 2 nuclei splits to form two identical daughter cells.

3. INTERPHASE
 Longest stage in the cel l cycle
 During this phase DNA is in the form of chromatin
 Divided into three par ts
1. Growth and Preparation: Cell increases in size while performing its
usual functions
1. DNA Replication: DNA replicates making an exact copy of itself
1. Continued Growth and Preparation: Cell continues to grow and
makes copies of its organelles

4. INTERPHASE – DNA REPLICATION

5. MITOSIS
 Shor test stage in the cel l cycle
 Contents of the nucleus divide resulting in two daughter
nuclei that are identical to the original parent cel l

6.  Impor tant structures:
MITOSIS
 Spindle Fibers: Protein structures that move chromosomes during
mitosis
 Centrioles (Animal cells only): Organelles that control the spindle
fibers. *add label to animal cell diagram

7.  Mitosis is divided into 4 stages (PMAT)
1. Prophase (early prophase & late prophase)
2. Metaphase
3. Anaphase
4. Telophase
MITOSIS

8. MITOSIS - PROPHASE
Early Prophase
 Dupl icated chromosomes
condense into X-shape
 Nucleolus disappears
 Spindle fibers star t to form
and spread across the cel l
 Centrioles move to opposite
ends of the cel l
Late Prophase
 Spindle fibers complete
forming
 Spindle fibers attach to
chromosomes at the
centromere
 Nuclear membrane
disappears

9. MITOSIS - METAPHASE
 Spindle fibers pul l chromosomes into a l ine across the
metaphase plate at the center of the cel l

10. MITOSIS - ANAPHASE
 Spindle fibers contract and shor ten to separate sister
chromatids and pul l to opposite ends of the cel l
 Once separated, sister chromatids are now considered
daughter chromosomes

11. MITOSIS - TELOPHASE
 Final stage of mitosis
 A complete set of chromosomes is at each end of the cel l
 Nuclear membranes form around each set of chromosomes
 Nucleolus reappears
 Spindle fibers disappear
 There are two nuclei in one cel l

12. CYTOKINESIS
 Final stage of the cel l cycle
 Cel l with two nuclei spl its into two daughter cel ls
 New cel ls are identical to each other and to the parent cel l
 Cytokinesis is di f ferent in plant and animal cel ls due to the
presence of a cel l wal l in plants.
 Animal cell: Cell membrane pinches together to separate two halves
 Plant cell: Cell plate forms along center of the cell

14. MITOSIS: http://youtu.be/aDAw2Zg4IgE