Why are fungi not classified as plants?
Initially, Fungi were classified as plants but that was long ago, the invention of the microscope saw it classified separately under the Eukaryotic Organisms. Unlike plant fungi are multicellular (except Saccharomyces cerviseae), multinucleate (some of it cells have two nuclei), their cell walls are made of chitin and are also heterotrophic (they do not contain chlorophyll thus are incapable of photosynthesis but derive their energy from living or dead organisms). All these characteristics are what make the Fungi completely different from plants.
How are Fungi different from plants?
Below is a detailed explanation of different characteristics that make the Fungi different from plants. We will compare some of the components that are in plants and are not in the fungi.
Cell walls
The Fungi cell walls are made of Chitin while the plant’s cell walls are cellulose.
Plants are Autotrophs while Fungi are Heterotrophs
Fungi do not synthesis chlorophyll thus does not go through the process of photosynthesis in order to manufacture food. They are Heterotrophs and rely on living or dead organisms for their nutrients. Plants leaves contain Chlorophyll which aids in the process of photosynthesis.
Lack of Roots
Fungi do not have roots, instead, they grow from the tips of filament known as Hyphae which is part of their bodies (Mycelia), they then digest the organic matter which they are attached to externally before absorbing them into the Mycelia. Plants on the other hand have roots that support them on the soil and are also used to obtain nutrients and water from the soil.
Reproduction
Fungi can reproduce both sexually or asexually. Both processes of reproduction in Fungi can generate spores. Spores are special cells which when generated and let into an environment that is suitable for their growth give rise to new fungal bodies. The spores are spread to new habitations by either air or water. Plants, on the other hand, contain seeds, pollen, and fruits that are used for reproduction.
Storage of food
Fungi store their food in form of glycogen while Plants store their food in form of starch.
Trophic Level
Fungi are decomposers of expired biological material Plants are the producers of food. Fungi can either be unicellular (Yeast) or Multicellular (Mushrooms) while all true plants have multiple cells. Fungi have filaments while plants are made up of stems and leaves.
All of the above are some of the ways in which Fungi are different from plants. One might wonder then why they were initially classified as plants and then later on separated. The differences are clear but there is the main difference between Fungi and Plants that stands out. The major features are very distinctive between these two are in the way they obtain their nutrients and their cell walls:
The Fungi cell wall is made of Chitin while the plant’s cell walls are made of cellulose. Fungi contain N-acetylglucosamine which is the material component that polymerizes into chitin while plants contain glucose which polymerizes into glucose.
The difference in how they get their nutrients.
The difference in their cell walls
Fungi are heterotrophic which means that they get their nutrients from both living and dead organisms while plants are Autotrophic which means they manufacture their own food using light carbon dioxide and water. Plants have chlorophyll which aids in the process of absorption of light water and carbon dioxide during photosynthesis which is not present in Fungi.
What separates Fungi from Plants?
Fungi have very different components that separate them completely from plants. Here are some Fungi components that separate them from Plants:
Fungi are classified under their own kingdom just like plants. The Kingdom Fungi is said to have 144,000 species that are known. So on it is own is a very huge kingdom. Examples of organisms under Kingdom Fungi include mushrooms, yeasts, smuts, molds, and mildews among others.
Fungi have different structures from plants.
The Two belong to two different Kingdoms.
Even though initially Fungi was classified under plants due to some similarities fungi have a very different structure that is unique. Here are some of the components of its structure:
The cell wall of Fungi also has a protoplast. The protoplast is differentiated into the other parts of the cells like cytoplasm, nuclei, cell organelles, and cell membranes. The nuclei of the Fungi are surrounded by a nuclear membrane. The nucleus is clear, dense, and has chromatin threads. Fungi are made up of thread-like structure which is known as hyphae, the hyphae come together to form a mesh-like structure which is known as mycelium. The Fungi cell walls are made of Chitin. Most of the Fungi are multicellular but there are those that are unicellular like the Yeast. Most of the Fungi species structures are made up of filaments except for the yeast.
Classification of Fungi
Species in the Kingdom Fungi are classified based on modes. They are modes of nutrition and mode of spore formation. By Mode of spore formation Based on the mode of spore formation, Fungi are classified into the following groups.
Basidiomycetes: Their sexual spores are called basidiospores. Asexual reproduction in this species occurs through budding, fragmentation, or candida.
Deuteromycetes: They reproduce asexually.
Zygomycetes: Their sexual spores in these groups are called zygospores while the asexual spores are called sporangiospores. Reproduction takes place through the fusion of two different cells.
Ascomocytes: The spores of these Fungi are called ascospores. They are sexual spores. By mode of nutrition. Basing on the mode of nutrition, Kingdom Fungi is classified into three groups.
They include:
Symbiotic: This is where the fungi form an interdependent relationship with other species in which both of the two organisms mutually benefit from each other. Examples of these Fungi include mycorrhiza, Lichens.
Saprophytic: This where Fungi obtain their nutrition by feeding on the body of dead organic substances. Examples are Penicillium and Rhizopus.
Parasitic: This is where Fungi obtain nutrients by living on other living organisms. The organisms can either be plants or animals. Examples include Puccinia and Taphrina.
The difference in Reproduction
Reproductions in Fungi are both asexual and sexual. The sexual mode of reproduction is known as teleomorph while the asexual one is called anamorph.
These major components of the Kingdom Fungi are what majorly separate this kingdom from the Plant Kingdom. The two are totally different like we have discussed based on the most basic components that are most important in living organisms. These are things like nutrition, reproduction, and their modes of classification.
Which came first Fungi or Plants?
Over the years there have and been a lot of controversy and debate about Plants and Fungi in relation to which one of two came first into the land. Still, this debate has not been put to rest due to the lack of supportive evidence. Even though it is not clear there has been a development according to research that has made researchers believe that Fungi first on land before Plants.
Recently, a group of researchers found a fossil that is believed to belong to Fungi which dated 800 million years ago. After Rigorous research, it was found out that indeed this Fossil belonged to the Fungi Kingdom. The fossils had distinctive features that are similar to those of Fungi like its filaments extend in a mesh woven manner, it contains chitin on its exterior and this shows clearly it was a fungus.
It is also believed that Fungi are the ones that paved the way for plants on land. This is because research shows that without the availability of Fungi to break down waste to release nutrients, plants wouldn’t have found nutrients in the ground, and would have been difficult for them to survive. So fungi are believed to have emerged first then created a symbiotic relationship with plants and thus aided in their spread.
Basing on this research, we can say that the fungi were the first one though it is still a large topic under discussion due to various controversies that surround it.
Do Fungi need sunlight?
A fungus depends on other organisms both living and dead in order to gain their nutrients. Most of the Fungi are not food producers but are rather decomposers. Fungi do not need Sunlight because they do not manufacture food like plants through the process of photosynthesis.
The fungus also doesn’t need sunlight in any aspect of their life cycles for their survival. The fungus needs moisture, a food source, and oxygen in order to grow so sunlight is not that important for them.
How do the Fungi reproduce?
Fungi can reproduce both sexually and asexually. Both of these modes of reproduction in Fungi are made possible because Fungi can generate special cells known as spores that are used for reproduction. When released into an environment that is conducive for Fungi growth, the spores can give rise to brand new fungal bodies. These special cells are spread into new environments through either water or air.
Now let’s look into the two modes in which Fungi can reproduce in detail.
Asexual Reproduction
Asexual reproduction in Fungi occurs through a process that is known as Mitosis. This is where fungal cells produce genetic copies that are identical to it through the division of its cells. In Fungi that are Single-Celled like the Yeast, they go through a process known as budding during reproduction. This is where a bud will emerge from the parent cell and gradually grows to the parent size.
Fungi that are multi-cellular on the other hand, reproduce by forming asexual spores. The examples of this type of Fungi are Molds. The asexual reproduction of multi-cellular Fungi varies in different species of Fungi, so the processes and timing of the asexual reproduction are very different in each of the different species of multi-cellular Fungi.
Sexual Reproduction
The sexual reproduction in Fungi takes place through the process of Meiosis. The Fungi produces spores through meiosis, these spores are made up of half of their parent chromosomes. When the spores are released they grow into Mycelia that are tree-like and at this stage, they are ready to mate. In some Fungi like mushrooms, toadstools, and puffballs the branched mycelium also known as primary mycelium is further divided into various segments that contain one nucleus. The process of mating takes place where two different primary mycelia, come into contact to form a secondary mycelium. Each of the segments that form the secondary mycelium is made up of two nuclei; the nuclei are from the original segment and contain half the number of the chromosomes that were from the parent cell. This is how Fungi reproduce sexually.
If Fungi are not plants then are they animals?
Fungi in the past were considered as plants which are not the case now; even though they aren’t plants they are definitely not animals. Fungi are classified independently in their own kingdom just like plants and animals. So, though Fungi aren’t animals scientific research has proofed Fungi to be closely related to the animals. This is because Fungi have some similar characteristics to the animals. They include:
Both are multicellular (except yeast which is in the only unicellular Fungi). Both animals and Fungi are heterotrophic they both depend on other organisms to feed and do not synthesize their own food like plants. Like some animals, their cell walls are made of Chitin. Chitin in some animals is the polysaccharides that are responsible for the hardness in their skeletons as insects, Lobsters, and others. Just like animals, they store reserve food in form of glycogen.
Even though Fungi shares some similarities with animals, like we have said they are not Animals. They have various distinctive features that make them totally different and not to be classified in the same kingdom. They include:
Mobility: Fungi do not have the ability to move around like animals
Reproduction: Fungi reproduce both sexually and asexually while the animals reproduce sexually only.
Mode of nutrition: Even though Fungi and animals are heterotrophic, they also have other modes of feeding. For instance, Fungi also feed through absorption while animals are also holozoic.
Life cycle: Fungi have a complex life cycle where during the reproductive stage the fungus alternates through the haploid phase and a diploid phase where the Fungi reproduce sexually. Animals have a simple life cycle, where the animals mate sexually to produce sperms and eggs which fertilize and become a zygote that grows into adulthood.
Response: Fungi are very slow in the way they react and respond to environmental changes while Animals respond quickly to external changes this is because they contain nerve cells that are responsible for the response.
Response: Fungi are very slow in the way they react and respond to environmental changes while Animals respond quickly to external changes this is because they contain nerve cells that are responsible for the response. All fungi have a rigid cell wall which is made of Chitin where not all animals have Chitin, and also animals do not have a cell wall.
Body structure: The Fungal body is known as the Thallus, it is made up of multiple cells with filaments called hyphae. The filaments combined to form a network which is known as Mycelium. This is completely different from the human body which is also multi-cellular though these cells are differentiated into organs, tissues, and organ systems. Fungi mostly have the haploid stage which is dominant in its life cycle while Animals have a diploid life cycle which is dominant. In Animals, the haploid phase is only in gametes. Fungi also have the Dikaryotic phase which is absent in animal. From the above analysis, it is clear that though animals and Fungi have some similarities they cannot qualify to be classified under the same Kingdom. They both also have very distinctive features that are unique in their own way but compared to plants they are closely related to Animals.
Fungi are an underrated kingdom though is they are among the most important organisms to exist on the planet. Fungi have a lot of importance in the day to day lives of all organisms.
Some of these importance’s include:
Fungi are also very important in human life and can be used in manufacturing a lot of things used by human-like insect sides and many other things. Some Fungi are edible like mushrooms, morels, and truffles. Fungi are responsible for breaking down organic matter.
In conclusion, we have clearly analyzed the unique components and characteristics that separate Fungi from other organisms that they have been linked to like plants and animals. We have found out that Fungi are closely related to animals than they are to plants though that doesn’t mean they are animals. Fungi are classified solely under their own kingdom and rank the same as the two.
