Flashcards in The cell cycle Deck (16):
What is the cell cycle?
-Highly ordered sequence of events that take place in a cell, resulting in cell division and formation of two identical daughter cells.
What are the two main phases of the cell cycle?
What is interphase?
-Long periods of growth and normal working separate divisions.
-E.g. produces enzymes or hormones, and actively prepares for cell division.
What happens during interphase?
-DNA is replicated and checked for errors in nucleus.
-Protein synthesis occurs.
-Mitochondria grow and divide.
-Chloroplasts grow and divide.
-Normal metabolic processes occur.
What are the three stages of interphase?
What happens in the G1 phase?
-First growth phase.
-Proteins from which organelles are synthesised are produced and organelles replicated.
-Cell increases in size.
What happens in the synthesis phase?
-DNA is replicated in nucleus.
What happens in the G2 phase?
-Second growth phase.
-Cell size continues to increase.
-Energy stores are increased and duplicated DNA checked for errors.
What is the mitotic phase?
-Period of cell division.
-Involves mitosis and cytokinesis.
What is mitosis?
-Nucleus is divided
What is cytokinesis?
-Cytoplasm divides and two cells are produced.
What is the Go phase?
-When the cell leaves the cycle either temporarily or permanently due to:
-Differentiation- a cell that becomes specialised is no longer to divide.
-DNA damaged- cell is no longer able to divide.
-Too many body cells- too many cells can causes diseases like cancer.
What are checkpoints?
-Control mechanisms of the cell cycle.
-Monitor and verify whether each process has been accurate.
What is the G1 checkpoint?
-At the end of G1 and before entry to S phase.
-If cell satisfies requirements then it triggers DNA replication if not then enters Go.
What is the G2 checkpoint?
-At the end of G2 and before start of mitotic phase.
-Has to check whether DNA has been replicated without error, if it has then signals beginning of mitosis.