Do we use fusion in real life? why or why not?

Yes..? Kind of.

Explanation:

Fusion is the combination of lighter nuclei into heavier nuclei. Yes, this is seen in nature; the sun. The sun is an example of fusion. However, on earth, no. To fuse 2 nuclei, you need extreme temperature and extreme pressure to fuse them together because the nuclei are the same charges. So, yes, but not really?

i think its the first one

both male and female gametes are produced by meiosis of the germ cells. therefore, both male and female gametes are haploid. one male and one female gamete unite during the fertilization to form the diploid zygote. in seed bearing plants, pollen grain is the male gametophyte, which produces sperm cells.