When does the cell cycle start? when does it end?

Solution:

The cell cycle is continuous because our cells are constantly dying and making new cells.  

It is is made up of:

1 phase: things inside of the cell begin to grow.  

Middle phase: DNA and only the DNA divides  

Last phase: All other organelles divide  

Then finally comes Mitosis which has:  

Prophase: chromosomes condense, centrioles move to opposite poles, nuclear membrane dissolves, spindle begins to form  

Prometaphase: smindles attach to chromosomes (but they are not aligned)  

Metaphase: chromosomes are on the metaphase plate. They are lined in the center.  

Anaphase: spindles pull the sister chromatids apart  

Telophase: everything that happened in phrophase..but the OPPOSITE!  

Thus we get finally is Cytokinisis where the cell divides

that is wrong, its not thymus.