Origin of sex and Multicellular organisms

Question 1

Origin of sex

Answer 1

Eukaryotes initially divided by mitosis, asexually, then by meiosis, sexually

In asexually reproducing organisms, the only variation is due to mutation

In sexually reproducing organisms, variation due to mutation, independent assortment and crossing over

Four theories why sex evolved
-A method of adapting to change by evolving faster
-A method of fending off disease/parasites
-A method of repairing genes
-Historical accident

Sex evolved ~1,200 MA

Sexual reproduction speeds up evolution, good at keeping good mutations, getting rid of mistakes

Question 2

Origin of multicellular life

Answer 2

Multicellular life evolved multiple times independently

It evolved in colonies, each cell allows the division of labour