Risk-on risk-off is an investment setting in which price behavior responds to and is driven by changes in investor risk tolerance. Risk-on risk-off refers to changes in investment activity in response to global economic patterns.
Meiosis is necessary in order for sexual reproduction to occur. It ensures that when the gametes (eg. sperm and egg) combine, the new organism has the correct number of chromosomes.
This is important in sexually reproducing organisms because meiosis is the cell division used in gamete formation. When two gametes come together in sexual reproduction, they combine to create one cell (or zygote).