Now the plants are gradually evolved from the original single-cell plants. In the early single-cell plants, only one cell is performing the function of growth and can survive on its own. With the change of the external environment, single cells have been unable to adapt to the growth environment at that time, so they began to gradually evolve into multicellular plants, which basically show the appearance of plants now. In the process of continuous evolution and development, the structure and function of various cells in multicellular plants gradually become thinner, and they also have the functions of growth, flowering, and bearing, etc., but some plants still take the form of retaining the original single cell due to the small environmental changes.
At the beginning, it was very simple, just a single-cell fungus plant, without organs such as roots, stems and leaves, or chlorophyll synthesis nutrients. With the development, it has evolved into algal plants. At this time, there are already chlorophyll, which can absorb sunlight to synthesize nutrients. Later, there are lichens composed of algae and mycelium. After that, the environment changed a lot, and it needs to evolve to adapt to growth. Lichens gradually evolved into bryophytes, later into ferns, and then the seed plants.
