Cell Division Flashcards
What does the nucleus of the cell contain?
Chromosomes.
What do chromosomes contain?
Linear arrangements of genes. They are found in PAIRS in all body cells.
How many pairs of chromosomes are in the body cells.
23 pairs
Human chromosomes
A single chromosome has lots of information on how to build your body. What is each bit of information called?
Gene
How are genes found in chromosomes?
In pairs. Pairs of genes are found opposite each other at the same position.
Different genes control -
different characteristics
Genes are arranged -
in a row along a chromosome.
How are new cells formed?
When old cells divide.
What are the two types of cell divisions?
- Mitosis
- Meiosis
Cell division by mitosis
enables organisms to grow, replace worn out cells and repair damaged tissues.
Cell division by meiosis
occurs during the formation of gametes.
When Mitosis?
- GROWTH
- Replace dead cells
- Repair damaged cells
When meiosis?
Production of gametes.
What are gametes?
Sex cells
Number of chromosomes during mitosis?
46 (same as original)
Number of chromosomes during meiosis?
23 (half of the number)
What is the genetic composition during mitosis?
Identical
What is the genetic composition during meiosis?
Variation
Number of daughter cells in mitosis?
2
Number of daughter cells in meiosis?
4
Mitosis vs Meiosis
Define cancer cells
Mitosis is closely controlled by the genes inside every cell. Sometimes this control can go wrong. If that happens in just a single cell, it can replicate itself to make new cells that are also out of control. These cells continue to replicate rapidly without the control of normal cells. Cancer cells will form lumps or tumours, that damage the surrounding tissues. Sometimes cancer cells break off from the original tumour and spread in the blood to other parts of the body.
Explain the chemotherapy treatment
Medicines that are used to treat cancer are sometimes aimed at killing cells that are rapidly dividing by mitosis. They inhibit the synthesis or function of DNA.
