Studied by 1 personWhy are new cells created?
Growth and repair of body cells
Production of specialised sex cells
Give facts about chromosomes
Controls the functions of a cell
Has instructions from the DNA to build up an adult from a fertilised egg cell
carry DNA in a cell
Must copy the DNA accurately
what is Meiosis, Mitosis and gametes?
Mitosis - A single cell divides twice to make 4 daughter cells, which carry half of the genetic information.
Meiois - A single cell divides into 4 cells
Gametes - another name for Sex cells
What is Chromatid?
A chromosome which has two distinctive halves
How many chromosomes does a sperm and egg cell have
23 chromosomes
How many cells does a human cell contain
46 chromosomes
What happens if there is an extra chromosome
Cell dies
Why does some people have genetic disorders like down syndrome?
Because they have an extra chromosome
Explain the stages of cell mitosis
Stage 1 - the single cell grows and develops, carries normal activities
Stage 2 - Chromosomes doubles into pairs
Stage 3 - Cell divides into two daughter cells which carry each parent DNA
Define Gene and DNA
Gene - Contains information (section of DNA) that forms the characteristics, appearance etc
DNA - Unique Chemical which contains genetic material
Suggest why it is important for chromosomes to stay the same when a cell divides to make other cells (3 Marks)
Organism might die
Lacks vital genes
Cell wouldn’t work properly
Note
Flashcard