Q. Concerning their biological function what is the difference between meiosis and mitosis?

The main biological function of mitosis is cellular multiplication a fundamental process for the development and growth of tissue renewing, multicellular organisms, asexual reproduction, and so on.

The biological function of meiosis is gamete formation in gametic meiosis or spore formation in sporic meiosis that is the production of cells qualified for sexual reproduction with half the quantity of chromosomes compared to the original cell.

There is a special type of meiosis that happens in zygotes of some algae, fungi and protozoans this meiosis, called zygotic meiosis, has the function of reducing to a half the number of chromosomes of adult individuals that will be formed from the zygote. In species along with zygotic meiosis the adult individuals are haploid and they form gametes by mitosis. These gametes fuse in pairs with the others and generate a diploid zygote that then undergoes meiosis to restitute the normal ploidy of adult individuals.