Both Meiosis and Fertilization are essential to maintain chromosome number, constant. Why?

Explanation

(i) The germ cells which produce gametes are diploid (meiocytes). They undergo meiosis to produce haploid gametes.
(ii) These haploid male and female gametes fuse (fertilisation) to produce diploid zygote. This helps in restoring and maintenance of chromosome number constant in a species generation after generation. So both meiosis and fertilisation are essential.