What is the difference between the structure of cells of unicellular algae and the structure of cells of multicellular plants?

1) One of the most important organelles, the chloroplast, is different. In algae, chloroplasts can vary in number, size, and shape over a wide range, while in the overwhelming majority of multicellular plants in the cell there are relatively many not very large chloroplasts. It is very important – multicellular plants never have a pyrenoid in chloroplasts, while algae usually do.
2) There are different substances in the composition of the cell walls of algae and higher plants.
3) The list of reserve carbohydrates of unicellular algae is simply huge: chrysolaminarin, mannan, purple starch, etc. Most multicellular plants are limited to starch or substances significantly similar to it.