Question: when does the mitochondria replicate in the cell cycle

title: Cell cycle
text: The first phase within interphase , from the end of the previous M phase until the beginning of DNA synthesis , is called G ( G indicating gap ) . It is also called the growth phase . During this phase , the biosynthetic activities of the cell , which are considerably slowed down during M phase , resume at a high rate . The duration of G is highly variable , even among different cells of the same species . In this phase , the cell increases its supply of proteins , increases the number of organelles ( such as mitochondria , ribosomes ) , and grows in size . In G phase , a cell has three options . ( 1 ) To continue cell cycle and enter S phase ( 2 ) Stop cell cycle and enter G phase for undergoing differentiation. ( 3 ) Get arrested in G phase hence it may enter G phase or re-enter cell cycle . The deciding factor is availability of nitrogens and storage of energy rich compunds at the deciding point called check point . This check point is called G cyclin or C. It causes transition of G to S phase . Once the check point of G phase is crossed , cell cycle will go uninterrupted till it is completed . S 

Answer: answer: In the growth phase, the cell increases its supply of proteins , increases the number of organelles ( such as mitochondria , ribosomes ) , and grows in size .