Why must gametes be haploid?

Gametes must be haploid because they combine during fertilization to form a diploid zygote. In sexual reproduction, organisms produce gametes, which are reproductive cells (sperm in males and eggs in females). These gametes carry half the genetic information of the organism, meaning they are haploid with only one set of chromosomes.

When two haploid gametes fuse during fertilization, they create a diploid zygote, restoring the full set of chromosomes that the organism will have. This ensures genetic diversity and continuity of the species, as the offspring receive half of their genes from each parent. Thus, the haploid nature of gametes is crucial for maintaining the correct chromosome number across generations and facilitating sexual reproduction.