Table of Contents
Introduction:
Lichen is not a single organism but a symbiosis among various organisms such as fungi and cyanobacteria or algae. Cyanobacteria are also called blue algae despite being different from algae. The non-mold part is known as the chlorophyll photobiont. Most lichen compounds combine one photobiont with one mycobiont that is not ubiquitous and there are lichens with more than one photobiont partner. The fungus partner is considered to be made up of filamentous cells and all the fibers are known as hyphae. These hyphae may have a branch but maintain a continuous distance and grow by extension. There are a few lichens with a filamentous structure between photobionts while others comprise chains of more or fewer cells.
Ascomycetes or Basidiomycetes species are the most common fungi in lichens. Common algal partners can be the green algae Chlorophyta or the Cyanophyceae family of blue bacteria. Normally, fungal partners cannot survive without their phycobiont, but algae can often live independently in water or on wet soil. The largest lichen can make the thallus up to 3ft tall, although most of them are smaller than a few inches. They are colorful, ranging from yellow to green and black.
In particular, sleep is growing slowly. Those where phycobiont is a blue bacterium have the ability to convert nitrogen gas into ammonia. Some can live for hundreds of years, especially those living in tropical areas such as the arctic tundra or alpine.
Types of Lichens
Licenses exist in one of the growth forms mentioned below.
- Crustose grows across the substrate.
- Foliose are sheets of flat, leaf-like tissue and are not tied together.
- Squamulose is closely spaced and illuminated by flat stone units.
- Fruticose is found naturally in standing branch tubes.
Like the basic growth variants, lichens have the same internal morphology. The fungi of the fungus partner form a mass of the lichen body, and the lichen layers are defined by the relative proportions of these fibers.
Fibers are packed close to the outside to form a vortex that helps to communicate with the environment.
Partner algal cells are not distributed under the cortex as the fungal fibers disperse. The medulla is below the algal layer which is a loose woven layer of fungal fibers. There is another layer beneath the medulla in foliose lichens and it comes in direct contact with the substrate below the squamulose and crustose lichens.
Mosses and Lichens
Mosses are multicellular organism that contains tracts made of photosynthetic cells, such as trees, ferns, and wildflowers.
But unlike these artificial plants, algae do not have special tissues that actively carry water and nutrients, such as water, from the bottom to the edges of the leaves, and vice versa.
Instead, like a leafy and green sponge, mosses simply absorb water and nutrients. This means they cannot grow very tall or be in danger of drying up.
Algae, in contrast, is a mixture of at least two different organisms, fungi, and algae, which live together as one.
In the simplest case, the fungus surrounds the algae colony. Algal cells provide fungi for food through photosynthesis, while the fungus partner protects the algae from dryness and sun damage.
When wet, the algae can be seen on the top layer of the mold, giving it a green, silky layer. But when dry, lichens are rarely green, and instead, come in many bright colors. Lichens also have a variety of growths, but they do not have leaves of any kind, which helps to separate them from mosses.
Lichens are sensitive to nitrogen (N) pollutants because they absorb all their nutrients and water in a wet and dry atmosphere (falls). Nitrogen supplementation can increase the nutrient load.
Lichen is an association between one or two species of fungi and algae or cyanobacterium (blue algae) that lead to a different form in the symbionts. Although dung appears to be a single plant organism, under a microscope the organisms appear to contain millions of algae cells (called phycobiont) woven into a matrix made of fungal fibers (called mycobiont). Many mycobionts belong to the same Ascomycota group called Lecanoromycetes, which is characterized by an open, button-shaped fruit called apothecium. Although sleep has long been thought to combine one fungus with one phycobiont, studies show that many macrolichens also incorporate a specific basidiomycete yeast into the cortex of an organism. There are several types of mycobionts, although part of the lichen system contains Trebouxia, single-celled green algae. There are about 15 species of cyanobacteria that act as photobionts in lichen organisms, including members of the Calothrix, Gloeocapsa, and Nostoc.
Also read: Important Topic OF Biology: Taxonomy & Systematics
FAQs
What are lichens?
Lichen is a symbiosis of various organisms such as fungus and cyanobacteria or algae. Cyanobacteria are also known as blue algae without separation from algae. The non-mold part is called a photobiont that contains chlorophyll. Many lichen partners including one photobiont and one mycobiont are not all and lichen with more than one photobiont partner is also present in some cases. The fungus partner is made up of filamentous cells, where all the fibers are called hyphae.
Q. What are the characteristics of lichens?
Ans: The most common fungus in lichens is the genus Ascomycetes or Basidiomycetes. The green algae Chlorophyta or the Cyanophyceae family of blue bacteria are the most common algae partners. Fungal partners cannot survive without their phycobiont, while algae can survive on their own in water or in wet soil. The color of lichens varies from yellow to green and dark hues.
Most lichens grow at a slower rate. Phycobiont is a blue bacterium that converts nitrogen gas into ammonia. Lichens living in tropical areas such as the arctic tundra or alpine are said to date back hundreds of years.
Q. What are the types of lichens?
Ans: Lichens are divided into three types:
- Crustose: Crustose is a lichen that attaches to what it grows. As the name suggests, it has a crust and forms a crust on the growing substrate (such as rocks, trees, or dirt). It is difficult to remove this crust.
- Fruticose: Fruticose looks like a small branched tree like a small leafy tree. It looks like green coral. It grows on rocks, trees, and in the ground. The word fruticose has a Latin origin which means tree or shrub
- Foliose: Foliose contains a leafy structure. It can be easily removed from the growing area. Foliose gets its name as it looks like the leaves of a plant leaf.
