B2.1 - Cell Division (Finished) Flashcards
What is contained within the nucleus of a cell
Chromosones
What is contained within chromosomes?
Genes
What does DNA stand for?
Spelling does matter
deoxyribonucleic acid
What do genes contain?
DNA
How many chromosomes are contained within the nucleus of any cell in your body?
46 chromosomes, they are arranged in 23 pairs. In each pair of chromosomes one is inherited from your mother and the other is inherited from your father.
How many chromosomes will someone have if they have Down’s syndrome?
47
What is mitosis?
Mitosis is a process in the cell cycle which produces two identical cells.
What is the size of a chromosome?
Chromosomes are roughly 1 or 2 micrometers long.
What happens in stage 1 of the cell cycle?
- The cells grow bigger
- They carry out their normal functions
- They replicate DNA to form 2 copies of each chromosome
- They increase the number of sub-cellular structures
What happens in stage 2 (mitosis) of the cell cycle? (Roughly)
One set of chromosomes is pulled to each end of the dividing cell and membranes are formed around them becoming two nuclei
What happens in stage 3 of the cell cycle?
The cytoplasm and cell membranes divide to form two identical cells
What is the cell-cycle?
A series of stages in which cells divide
Describe in detail what happens in mitosis?
1) The chromosomes line up at the centre of the cell
2) Cell fibres pull them appart to opposite ends of the cell
3) Membranes form around each set of chromosomes
4) These become the two new nuclei
How is DNA arranged in a dividing and non dividing cell?
In a non-dividing cell DNA is spread out into long strings, in one that is going to divide (when DNA is copied) the DNA forms x-shaped chromosomes
What is each arm of a chromosome?
An exact copy of the other
