Cell Division - Meiosis Flashcards
Gametes have half the usual number of what?
Chromosomes.
What happens during sexual reproduction?
To cells called gametes combine to form a new individual.
Gametes only have what?
One copy of each chromosome.
Why do gametes only have one copy of each chromosome?
So you can combine one sex cell from the ‘mother’ and one sex cell from the ‘father’.
End up with the right number of chromosomes in body cells.
What will the new individual have?
A mixture of 2 sets of chromosomes.
Inherit features from both parents.
Meiosis involves what?
Two divisions.
To make new cells which only have half the original number of chromosomes cells do what?
Divide by meiosis.
When does meiosis occur?
In humans, only in the reproductive organs.
What does the process meiosis produce?
Cells which have half the normal number of chromosomes.
In meiosis before the cell starts to divide what happens?
It duplicates its DNA.
One arm of each chromosome is what?
Exact copy of the other arm.
What happens in the first division in meiosis?
The chromosomes pairs line up in the centre of the cell.
The pairs pull apart…
Each new cell only has one copy of each chromosome.
Some of the father’s chromosomes and mother’s chromosomes…
Go into each new cell.
What happens in the second division?
Chromosomes line up again in the centre of the cell.
Arms of chromosomes are pulled apart.
