Chromosomes arrange themselves into pairs after replication
Meiosis
Produces cells with half the normal number of chromosomes
Gametes only have a single copy of each chromosome
Second division in meiosis
Chromosomes line up again in the centre of the cell and the arms of the chromosomes are pulled apart, resulting in four gametes, each with a single set of chromosomes
Embryo development
Cells start to differentiate into different types of specialized cells that make up a whole organism
Cell produced by gamete fusion
Replicates itself through mitosis to make a copy
To make gametes with half the original number of chromosomes
Cells divide by meiosis
Meiosis
Chromosomes duplicate before cell division, forming two-armed chromosomes where each arm is an exact copy of the other
Each gamete is genetically different from the others due to shuffling of chromosomes during meiosis
Gametes Are Produced by Meiosis
First division in meiosis
Chromosome pairs line up in the centre of the cell and are then pulled apart so each new cell only has one copy of each chromosome
Mitosis
Repeats many times to produce lots of new cells in an embryo
