The cell cycle Flashcards
Why do some cells undergo the cell cycle?
They are unable to divide continuously.
What are the three stages of the cell cycle?
Interphase, nuclear division, cytokinesis.
What happens during interphase?
Interphase occupies 90% of the cell cycle and is the period of time that involves no cell division. It is sometimes known as the resting phase.
What happens during nuclear division?
The nucleus divides into two (mitosis) or four (meiosis).
What happens during cytokinesis?
The cytoplasm divides to produce two or four new cells.
Typically, how long is the cell cycle of a mammalian cell?
24 hours.
What is cancer?
A group of diseases caused by a growth disorder of cells. It is the result of damage to the genes that regulate mitosis and the cell cycle. It leads to uncontrollable growth and division of cells.
What does cancer cause?
A group of abnormal cells called a tumour develops and constantly expands in size. A tumour becomes cancerous if it changes from benign to malignant.
What can the rate of mitosis be affected by?
The environment and by growth factors- it is controlled by two types of gene, a mutation to one of these results in uncontrolled mitosis.
What does the treatment of cancer involve?
Killing cells by blocking part of the cell cycle. As a result, the division and cancer growth ceases.
How do drugs used to treat cancer disrupt the cell cycle?
1) Preventing DNA from replicating
2) Inhibiting the metaphase stage of mitosis by interfering with spindle formation.
Why do cancer patients often loose their hair?
The drugs used to treat cancer also disrupt the cell cycle of normal cells. Hair-producing cells rapidly divide and are also vulnerable to damage.
