Table: Distinguishing Characteristics of Fungi and Lichens
Our natural ecosystem is made up of countless organisms. Some of them are also invisible to the naked eye. The flora and fauna of an ecosystem are so diverse that it incorporates billions of organisms that are part of an ecosystem and participate in it. A circular flow of nutrients takes place constantly in nature and all these organisms are critical for each other’s survival. An ecosystem comprises of autotrophs, which make their own food and heterotrophs, which are dependent on others to obtain food. However, sometimes, organisms also live together in a relationship with each other. This relationship can be parasitic, symbiotic or mutualistic in nature.
Fungi
Fungi are heterotrophic organisms that are eukaryotes. Fungi often exist in a symbiotic relationship with cyanobacteria such as green algae to form lichens. Fungi provide an anchor to the organism by providing protection and collecting nutrients, whereas, the algae prepares food for the fungi by the process of photosynthesis. Let us discuss the key points of difference between fungi and lichens.
Difference Between Fungi and Lichens
Fungi and lichens are organisms that are part of natural ecosystems. Fungi are heterotrophs and exist freely in nature but sometimes fungi and algae come together and get in a symbiotic relationship with each other. The algae part provides food and the fungi parts gives protection and collects nutrients from the environment. Before studying the points of difference between fungi and lichen, let us look at both of the organisms in detail.
Fungi
Fungi are multicellular organisms that are heterotrophic in nature. Heterotrophs are those organisms that cannot make their own food. Fungi are eukaryotic in nature, which means they have cell organelles like a nucleus. Fungi are essential to the smooth functioning of the natural ecosystem. Mycology is the term for the study of fungi. Fungi can reproduce by sexual and asexual modes of reproduction.
Yeast is single-celled fungi. Fungi also alternate between single and multicellular organisms depending upon the life cycle stage. Multicellular fungi have hyphae, which are tubular filament-like structures. The cell walls of fungi are made up of chitin, which is a hard substance commonly found in the exoskeletons of insects.
Fungi use the filament-like outgrowths to obtain food. Fungi can thrive in most environmental conditions and can obtain their food even from dead and decaying matter. This is the reason why fungi are essential to the natural ecosystem. Fungi clean up the dead and decaying matter by breaking it down. Also, fungi participate in symbiotic relationships with green algae to form lichens.
Lichens
Lichens are complex organisms arising out of a symbiotic relationship between algae and fungus. Fungus, being the dominant partner, gives lichens most of its characteristics. Anyone or both green algae and blue-green algae can be present in lichens. The fungus part provides protection and collects moisture and nutrients so that the algae can photosynthesize and makes food for the fungus needed for its growth.
Lichens can be found in a variety of habitats. Lichens are commonly found on tree barks, rocks, gravestones, walls, etc. Lichen is often confused with moss. Even though lichen and moss are non-vascular plants, only mosses are plants. According to estimates, around 6-8% or the landmass is covered with lichens.
Lichens are also of importance to human beings owing to the fact that they absorb pollutants from the atmosphere. Also, lichens make the study of pollutants in the air easier. Scientists can test the presence of pollutants in the air with the help of lichens. Lichens also have economic importance.
What is the Difference Between Fungi and Lichens?
Fungi and lichens are organisms that are abundant in our ecosystem. Both organisms have important functions in the ecosystem. Fungi clean up the ecosystem by breaking down dead and decaying matter whereas lichens absorb pollutants from the atmosphere. The point of difference between fungi and lichens are given below:
Difference Between Fungi and Lichens
The Relation between Lichen and Fungi
Students must have heard about fungi many times. Because they are the primary reason for the infections developed and also because of poisoning as a result of choosing harmful mushrooms. However, lichens might be a new term. They are a combination of fungi and algae. And are responsible for the indication of pollution in the environment. And that is the exact relation of lichen and fungi is having. The symbiotic relationship existing between the two helps us in so many ways.
The symbiotic relationship means that both the organisms involved will get the benefits. The other term for it is mutualism. And how they benefit from each other is by satisfying the needs of each other. For fungus, photosynthesis is obtained from algae. And with the help of fungus, algae can grow in drier environments.
So you might be wondering how it indicates the pollution, right? It is the sulphur dioxide in the atmosphere that destroys the lichen to exist and thus you will see only green algae. So lichens are seen in the area where there is no pollution.
Edible Fungi
From the time humans started exploring the land and marine, resources for food also went diverse. And one such was mushrooms. However, we end up choosing the harmful ones causing poisoning and allergies. And many went on to be seriously injured too. So it is high time, students must have the proper knowledge for identifying the good and bad fungi.
And just like dividing down any complex steps, there are also simpler ways for identifying them. Some of them are mentioned below:
Colour changes when they are cut.
Can identify from the smell.
Any kind of markings like spikes, bruises will also help.
Advantages and Disadvantages of Lichens
You have already learned how lichens help us identify pollution in the environment. So there are other advantages like
Food sources
For some birds and animals, they are natural habitats.
Provides nesting materials for the birds.
Helps to protect trees and rocks.
However, just like the flip side of a coin, there are disadvantages too for lichens. They are:
Some lichens are toxic.
They are poisonous at times.
In their raw form, they are indigestible.
Get to read more about lichens at the Vedantu website and the app.
FAQs on Fungi vs Lichens: What Sets Them Apart?
1. What is the fundamental difference between fungi and lichens?
The fundamental difference is that a fungus is a single, independent organism, while a lichen is a composite organism arising from a symbiotic relationship between a fungus (the mycobiont) and an alga or cyanobacterium (the phycobiont). Fungi are purely heterotrophic, whereas lichens function as a self-sufficient unit where the alga produces food through photosynthesis.
2. What is the symbiotic relationship between algae and fungi in lichens?
The relationship in lichens is one of mutualism. The fungal partner, called the mycobiont, provides structure, protection from UV radiation, and absorbs water and mineral nutrients from the environment. In return, the algal or cyanobacterial partner, the phycobiont, is photosynthetic and provides carbohydrates (food) for the fungus. This partnership allows lichens to colonise harsh environments where neither partner could survive alone.
3. What is the main structural difference between the cell walls of fungi and the algal component in lichens?
The primary structural difference lies in their composition. The cell wall of fungi is primarily made of chitin, a strong, complex polysaccharide. In contrast, the cell wall of the algal component (which belongs to Kingdom Plantae or Protista) is typically made of cellulose and other polysaccharides. This difference in cell wall material is a key distinguishing feature between the two kingdoms.
4. Are fungi typically unicellular or multicellular organisms?
Fungi exhibit both forms. The vast majority of fungi, such as mushrooms and moulds, are multicellular, composed of a network of thread-like structures called hyphae. However, some fungi are unicellular, with the most common example being yeasts (like Saccharomyces cerevisiae), which are crucial in baking and fermentation.
5. How are lichens used as bio-indicators in environmental studies?
Lichens are excellent bio-indicators of air quality because they are highly sensitive to atmospheric pollutants, particularly sulphur dioxide (SO₂). They absorb water and nutrients directly from the atmosphere, so any toxins present are quickly absorbed. The presence and diversity of lichens in an area indicate clean air, while their absence or decline signals high levels of pollution.
6. If a lichen is a combination of two different organisms, why is it often classified and named as a single entity?
Although composed of two partners, a lichen functions as a single, stable, and self-replicating physiological unit with a unique morphology and metabolism that is distinct from its constituent fungus or alga. The fungal partner determines the lichen's physical structure, and for classification purposes, the lichen is given the scientific name of the fungus. This is because the same fungus can sometimes form a lichen with different algal partners, but the overall form remains consistent.
7. What is the ecological importance of fungi, beyond their role in lichens?
Fungi are vital to ecosystems for several reasons. Their primary role is as principal decomposers, breaking down dead organic matter and recycling essential nutrients back into the soil. They also form crucial symbiotic relationships, such as:
Mycorrhizae: A mutualistic association between fungi and plant roots, which helps plants absorb water and nutrients.
Economic uses: Fungi are used in producing antibiotics (e.g., Penicillin), cheese, bread, and alcoholic beverages.
8. How does the mode of nutrition in fungi compare to that in animals?
Both fungi and animals are heterotrophic, meaning they cannot produce their own food. However, they differ in their method of obtaining nutrients. Animals ingest their food first and then digest it internally using enzymes within a digestive system (holozoic nutrition). In contrast, fungi perform external digestion. They secrete digestive enzymes into their surroundings to break down complex organic matter, and then absorb the resulting small nutrient molecules through their cell walls.
9. Can the fungal and algal partners of a lichen survive independently in nature?
While the algal or cyanobacterial partner can often be found living independently in nature, the fungal partner (mycobiont) is rarely found living on its own. The fungus is an obligate symbiont, meaning it is dependent on the phycobiont for its survival. This highlights the success of the lichen partnership, as it allows the fungus to thrive in environments it otherwise could not inhabit.
10. What are some examples of harmful fungi for plants and humans?
While many fungi are beneficial, some are pathogenic and cause diseases. For plants, fungi like Puccinia cause wheat rust, and smuts can damage cereal crops. For humans, harmful fungi can cause:
Infections: Such as athlete's foot and ringworm caused by dermatophytes, or more serious systemic infections like Aspergillosis.
Poisoning: Ingesting toxic mushrooms like the Death Cap (Amanita phalloides) can be fatal.
