The Cell Cycle Flashcards
What is the first of 3 stages of cell division?
Interphase which occupies most of the cell cycle, no division takes place.
What is the second of 3 stages of cell division?
Nuclear division, when the nucleus divides either into two (mitosis) or four (meiosis).
What is the third of 3 stages of cell division?
Division of the cytoplasm, known as cytokinesis. This follows nuclear division.
What is cancer and how is it caused?
Cancer is a group of diseases, caused by a growth disorder of cells. It is the result of damage to genes that regulate mitosis and the cell cycle, leading to uncontrolled growth and division of cells.
What can develop as a consequence of the uncontrolled growth of cancer?
A group of abnormal cells, called a tumour develops and rapidly expands in size. They can develop in any organ of the body, but most commonly in the lungs, prostate gland (m), breast and ovaries (f), large intestine, stomach, oesophagus and pancreas.
When does a tumour become cancerous?
If it changes from benign to malignant.
How can the rate of mitosis be affected?
By the environment of the cell and growth factors, and two types of genes.
What does a mutation in one of the genes controlling mitosis result in?
Uncontrolled mitosis, where the mutant cells formed are usually structurally and functionally different from normal cells.
What happens to the formed mutant cells?
Most dies, the survivors are able to divide into clones and form tumours.
What is the difference between malignant and benign tumours?
Malignant grow rapidly, are less compact and are more likely to be threatening. Benign grow more slowly, are more compact, and are less likely to be life threatening.
How is cancer usually treated?
Involves killing dividing cells by blocking a part of the cell cycle, and hence, cancer growth is ceased.
How does chemotherapy disrupt the cell cycle?
Prevents DNA from replicating.
Inhibits metaphase stage of mitosis by interfering with spindle formation.
What is the problem with such cancer drugs?
They disrupt the cycle of cells with a fast rate of division, meaning normal body cells, such as hair producing cells, are also vulnerable to damage.
