When we think of plants, practically everyone immediately imagines large trees, shrubs, or their favorite flowers. They are all complex organisms with macroscopic structures. However, when you enter the microscopic world, where life began, the possibilities multiply. Are there unicellular plants, in addition to the well-known multicellular ones? The answer is not simple, because it depends a lot on what we stick to when we talk about “plants”. Should we only take into account the kingdom Plantae, formed entirely by multicellular organisms, or can we also count on algae and fungi, commonly grouped, in certain areas, within the scope of the definition? Single-celled organisms continue to have a huge impact on the world. Did you know that it is estimated that more than 50% of the breathable oxygen produced on the planet comes from single-celled algae?
If you want to learn more about whether plants are unicellular or multicellular, and what are the characteristics of each of these, join us in this article.
Differences between unicellular and multicellular organisms
As a summary, we can indicate that the differences between unicellular and multicellular organisms are:
- The main difference is the number of cells that compose them. Therefore, it is as simple as knowing that unicellular are living beings that have only one cell and that, therefore, multicellular are made up of more than one cell.
- In the same way, they also differ from each other by belonging to different groups of living beings . In the case of unicellular beings, they are divided into the two main groups: prokaryotes and eukaryotes . However, multicellular beings only belong to the group of prokaryotes.
- Another differentiating factor between unicellular and multicellular organisms is their size . Obviously, in the case of unicellular beings we speak of beings of much smaller size than in the case of multicellular beings. In this way, thanks to their complexity, multicellular beings are those that we can see without using external tools, such as the microscope.
- However, despite the fact that unicellular or simple beings do not have complex structures, they are much more resistant to the incidence of environmental factors, being able to survive in extreme conditions where multicellular beings would be unable to stay alive. Hence, unicellular beings are of vital importance for the subsistence of the planet, as is the case of phytoplankton, formed by cyanobacteria and microscopic algae, most of them unicellular algae . The most representative of the latter are diatoms , capable of reproducing up to a million times a day.
- Finally, as we have just mentioned, in the case of unicellular beings, since they do not have complex structures, such as organs and tissues, they are capable not only of surviving longer, but of multiplying more quickly and efficiently. On the contrary, it happens with multicellular organisms, which do have unique and complex systems, organs and other structures that clearly differentiate them from each other before the human eye.
Are plants unicellular or multicellular organisms?
In general we can say that plants are multicellular organisms . However, there are cases of unicellular organisms that, although they do not belong to the kingdom of plants, are related to them in a certain way, which is why they are sometimes grouped with plants. For example, some do functions like photosynthesis. This is the case of some types of unicellular algae , such as microalgae, among which are diatoms, and mold and yeast belonging to the kingdom of fungi .
Examples of unicellular and multicellular plants
Here are some examples of unicellular and multicellular plants to increase your knowledge of ecology and more clearly appreciate the richness of life that surrounds us.
“Single-celled plants”
As we have already mentioned, within the kingdom of plants we will not find unicellular beings . But, in the case of algae, we do find a truthful classification of the types of unicellular algae based on their genetic and morphological differences. They are divided into four main groups: diatoms, brown algae, blue-green algae, and dinoflagellates. Here are some examples:
- Amphipleura kutzing (diatoms)
- Anabaena spp. (blue-green algae)
- Anphora ovalis (diatoms)
- Chroococcus turgidus (blue-green algae)
- Noctiluca scintillans (dinoflagellates)
- Peridinium depresum (dinoflagellates)
- Rivularia bullata (blue-green algae)
- Synura spp. (Brown algae)
- Stephanophyxis palmeriana (brown algae)
Multicellular plants
As for multicellular plants, we can say that they are much larger and that these, in turn, also have other types of algae, such as green and red. Within this group are also mosses , liverworts , angiosperms or gymnosperms .
- Andreaeopsida (mosses)
- Bryopsida (mosses)
- Cedrus atlantica (gymnosperms)
- Charophyceae (green algae)
- Chlorokybophyceae (green algae)
- Cupressus sempervirens (gymnosperms)
- Citrus × sinensis (angiosperms)
- Ginkgo biloba (gymnosperms)
- Lunularia (liverworts)
- Marchantia (liverworts)
- Papaver rhoeas (angiosperms)
- Pelargonium peltatum (angiosperms)
- Pinus pinea (gymnosperms)
- Klebsormidiophyceae (green algae)
- Sequoia sempervirens (gymnosperms)
- Sphagnopsida (mosses)
- Triticum durum (angiosperms)
