Because, it is the process by which they make or produce their food with the help of sunlight, water and carbon dioxide.
If photsynthesis is not there then there would be no production of food and ultimatley plants will die.
<span>Water heats up, changes to water vapor and evaporates, rises into the sky. It cools, condenses, turns back into liquid water forming clouds. Then it falls back to earth as precipitation and runs down hills or mountains during runoff and returns to lakes and oceans.
I think i`m not sure :)</span>
First of all, sex is a type of sexual reproduction. It’s meiosis. In meiosis, it has different stages and one of those stages is called Prophase 1. In prophase 1, genetic variation occurs.