Cell Division - Mitosis Flashcards
What do our cells have to do in order for us to survive and grow?
Cells have to divide.
Why does mitosis make new cells?
For growth and repair.
Body cells normally have 2 copies of what?
Of each chromosome
Where does each chromosome come from?
One from organism’s mother and one from organism’s father.
Humans have 2 copies of chromosome __ and 2 copies of chromosome __?
1.
2.
How many pair of chromosomes do humans have?
23 pairs
46 altogether.
What happens when a body cell divides?
It needs to make new cells identical to the original cell.
With the same number of chromosomes.
Mitosis is used in what 2 things?
Plants and animals.
Define mitosis
Mitosis is when a cell reproduces itself by splitting to from two identical offspring.
In a cell which isn’t dividing what is the DNA doing?
DNA is all spread out in long strings.
What happens when the cell gets signalled to divide?
It needs to duplicate the DNA.
1 copy for each new cell.
What happens when the DNA has been copied?
It forms x-shaped chromosomes.
Each ‘arm’ of the chromosome is what?
Exact duplicate of the other.
The left arm has the same amount of DNA as the…
Right arm in the chromosome.
Where do the chromosomes line up?
At the centre of the cell.
What pulls the cell apart?
Cell fibres.
What happens to the 2 arms of each chromosome?
They go to opposite ends of the cell.
What forms around each sets of the chromosomes?
Membranes.
The membranes become what?
The nuclei of the 2 cells.
Lastly, what divides?
Cytoplasm.
At the end of the process what do you have?
2 new cells containing exactly the same DNA.
They are identical.
What also uses Mitosis?
Asexual reproduction.
Some organisms also reproduce by what?
Mitosis.
Give an example of other organisms reproducing by mitosis?
Strawberry plants form runners in this way, which become new plants.
Offspring have the exact same what as their parents?
Same genes.
No variation.
