Fungi are included in a kingdom that comprises multicellular eukaryotic organisms that are heterotrophs such as those who cannot make their food themselves.
There are almost 44,000 known species of organisms of the fungi, some of which are the yeasts, rusts, smuts, mildews, moulds, and mushrooms.
- Fungi are invisible to the naked eye. Occasionally, few fungi will give rise to large ‘fruiting bodies’ known as mushrooms that bring about significant numbers of spores for reproduction.
- They are unicellular as well as multi-cellular organism.
- The cell wall contains protoplast which is further characterized into other cell parts e.g. plasma membrane, cytoplasm and nuclei.
- The nucleus is rigid and translucent with numerous fine chromatin threads. It is encased by a nuclear membrane.
- Mycology, the study of fungi is a very important field of biology because fungi are essential for many ecological and economic causes.
Some fungi possess structures similar to the plasmids (Strands of DNA). Mitochondria and a complex network of internal membranes, comprising the ER and Golgi apparatus are present in fungal cells. The major portion of the body of fungi is built from a framework of long, slender filaments known as ‘hyphae’. Hyphae filaments are composed of tubular cells that join end on end. Fungal cell walls are dense and comprise of complex polysaccharides known as chitin and glucans.
They can survive in every habitat, in almost every part of the earth but most abundant on land, in the water, air, and mostly in plants material and animals.
Fungi are mostly classified into four types:
- Chytridiomycota (chytrids)
- Zygomycota (bread moulds)
- Ascomycota (yeasts)
- Basidiomycota (club fungi).
Fungi reproduce sexually as well as asexually. Perfect fungi usually reproduce in both ways, but imperfect fungi are only capable to reproduce by asexual reproduction (mitosis). In both types of reproduction, fungi give rise to spores that separate from the parent in two ways; by wind or by riding on an animal. Fungal spores are small in size and light in weight than plant seeds, but they still are not easily released as high in the air. The huge puffball mushroom rupture and discharge millions of spores.
- Asexual reproduction takes place by fragmentation, budding, or spore formation.
- Sexual reproduction initiates genetic variation into a population of fungi. In fungi, unfavourable environmental conditions lead to sexual reproduction. Two mating types are produced.
- If both mating types are present in a single mycelium, it is known as homothallic mycelium, or self-fertile.
- In Heterothallic mycelia two non-identical, but harmonious mycelia are needed to reproduce sexually.
Fungi obtain their food by consuming diverse organic compounds from the environment. Just like animals, they cannot prepare their own food instead they utilize complex organic compounds as a reservoir of carbon.
Fungi get nutrients in two ways:
Few fungi are saprobes, organisms that gain nutrients from dead and decomposing organic matter.
Some fungi live in or on many organisms and acquire their required nutrients from their host
Comparison chart between fungus and mold
|Sr. No||Basis of comparison||Fungus||Mold|
|1||Description||The fungus is a unicellular or multicellular organism which produces spores and has a chitinous cell wall.||Mold is a huge group of multi- cellular thread-like fungi that are usually present in moist areas.|
|2||Colour variety||There is a wide variety of colours in fungi. They are smooth and colourful i.e. pink, green, brown, white etc||Mold is also colourful and usually observed to be purple, orange, black in colour.|
|3||Spore production||Fungi bring about numerous types of asexual spores.||They produce asexual spores called conidia.|
|4||Usage||Fungi are utilized in ethanol production and baking.||Mold plays a vital role in production of antibiotics.|
|5||Development stages||The fungus usually live as three different organisms: giant mushroom along with a fruiting body, unicellular organisms and multicellular molds with a complex organization of hyphae.||Mold begins its development as a single spore, which is known as a ‘mold spore.’|
|6||Growth||The fungus can grow in aerobic as well as anaerobic environment. It can easily grow anywhere on earth.||Mold requires damp or dark areas and aerobic condition for their growth.|
|7||Dangers to health||It can also put harmful effects on human health in form of lung disease, defected immune system and candidiasis.||It can also impose bad effects on human life i.e. it results into allergies and serious respiratory problems.|
Mold is a familiar type of fungus which contain many nuclei. It is thread-like fungi made up of hyphae, that grow in a moist, hot environment.
- The body of mold is known as thallus composed of hyphae which are columnar, branching tubular structure that lengthens by growth at the upper end.
- Their diameter is approximately 2-10 µm which is sub-divided into units by cross-walls referred to as septa.
- A pile of hyphae called mycelium is responsible for thready nature of mold.
- Photosynthesis is not the primary source to receive energy in molds.
These tiny organisms are found almost anywhere around us. Molds flourish in a damp environment.
The part of the mycelium that fixes the mold and obtains nutrients is known as the vegetative mycelium. Mold must acquire their food from other organic sources. Mold can not ‘eat’ its food. It must take in nutrients from many organisms. For this purpose, mold divide the large food substance into tiny organic molecules with the help of enzymes released by mycelia. By dead and decaying organic matter, molds play a vital role in material biodegradation.
Molds can reproduce by sexual as well as asexual reproduction. They give rise to significant numbers of little spores, which may be uninucleate (having one nucleus) or multinucleate. Spores of mold can be asexual (the output of mitosis) or sexual (the products of meiosis); the majority of the species have the ability to produce both types.
The part of mold that is capable of producing asexual reproductive spores is termed the aerial mycelium
Following are some sexual spores:
The asexual spores are:
The spores are nanosized cells which are discharged in the air. They act just like seeds and develop the mold community.
Examples of some mold
Here are a few species of mold: