While gymnosperms do use spores in their life cycle, they are not the only plants to do so.

Here's why:

* Gymnosperms: They use spores for their male gametophytes (pollen grains). They also have female gametophytes which develop within the ovule.

* Ferns, mosses, and other non-flowering plants: These plants reproduce primarily by spores, which are haploid cells that can develop into a new plant without fertilization. They are part of the "lower plants" group.

Therefore, while gymnosperms use spores, they are not the only plants to do so. Spore reproduction is a characteristic of a wider group of plants.