The origin of plants is very long. There were unicellular plants on the earth a long time ago. According to the current classification, that is, fungi and algae. At this time, there is only one cell in the plant, which has a very simple structure and belongs to prokaryotic cell. It can't absorb sunlight to synthesize nutrients through photosynthesis. It only depends on the nutrients in the environment for growth and life, and can't produce nutrients by itself. Then it will gradually evolve into a self-sustaining plant, namely cyanobacteria. They are small, but they can release O2 like real plants.
The evolutionary process of plants can be divided into three stages: the era of bacteria and algae, the era of naked Jue, the era of fern, the era of gymnosperms and the era of angiosperms. First of all, it's just a small fungus and algae. With the change of environment, the surrounding nutrition is difficult to meet the growth, and it has gradually evolved to a complex one. There are lichen plants, which are composed of algae and mycelium, or belong to low plants. The later evolution gradually became bryophyte, later fern appeared, with the increase of function, seed plants appeared.
