Here's why:
* Spore Reproduction: Spore reproduction is a form of asexual reproduction common in plants, fungi, and some bacteria. Spores are single cells that can develop into a new organism without the need for fertilization.
* Sexual Reproduction in Animals: Most animals reproduce sexually through the fusion of male and female gametes (sperm and egg), leading to the formation of a zygote that develops into a new individual.
While there are some exceptions, like the sponges (which can reproduce both sexually and asexually through budding or fragmentation), the vast majority of animals reproduce sexually through the process of fertilization.