Seed plants do not require water for their reproduction process. They transfer gametes by pollination and protect the embryo in enclosed seeds.

Different groups of gymnosperms are gnetophytes, cycads, gink-goes, and conifers.

see explanation.

400 million years ago, the Earth’s surface contained more water than the environment we have in the present. This allowed the seedless plants such as mosses and ferns to flourish because they favored a damp to wet surface. After a major change in the Earth’s atmosphere, the climate became hotter and drier. The plants adapted to the new environment by evolving into seed plants since the seed itself can survive extreme conditions.

**Bryophytes** only have one way to move water in their system, and this is through osmosis. However, 420 million years ago, the development of **vascular tissue** came and the small moss-like plants now suddenly evolved and were joined by other plant species that are now a meter tall, and others are the size of tall trees.

The presence of vascular tissue creates a great impact on the size of the plant because through this bundle of tissue the formation of the stem, and specialized organs in conducting water and nutrients throughout the plant are now possible.