 Now, the fungi, second group, fungi are the heterotrophs, that is they need organic carbon source as their food material and they have to, they are not able to convert the sunlight into energy or food. Fungi are also very widely distributed, present almost in all types of habitats. Their sizes ranges from microscopic fungi to very large ones. Microscopic fungi for example yeast, we commonly use yeast in our baking products, whenever we bake we use yeast. Yeast is a microscopic single cellular fungus. There are very large fungi, for example there are very large and huge mushrooms, we know that they are sometimes and mushrooms you know that these are the edible materials, but not all mushrooms are edible, some mushrooms are very large. These are the heterotrophs, these are the symbionts and these are the parasites, heterotrophs that is they need their food material from producers, that is from the organic source. They are symbionts, usually they make symbiotic relationship that is a relationship of give and take with some other organisms. For example there are some fungi which lives on the roots of plants or some other parts of say large trees and they help those plants in absorbing materials from the surrounding soil and from the plants they get their some parts of the food. They make a symbiotic relationship with many other kinds of organisms, particularly trees that is and plants and the algae. Many fungi are parasites, they also live as parasites that is they live inside or they live outside of the body of animals and plants and they can sometimes produce disease in those animals and plants. Now we talk about some distinguishing features fungi, fungi are from unicellular to multicellular as we previously mentioned yeast is a unicellular fungus. We can see the bread molds, there are some sometimes if we place our bread for longer time in outside the refrigerator for example in a room temperature then we see that greenish or brownish material grows on it. These are the bread molds the fungi which grow on that bread, there some part is penetrated inside the bread and some other part is present outside that bread and we can see a greenish rust or mass on the bread. They can also grow on other materials like different types of fruits. So fungi may be microscopic unicellular and fungi may be microscopic multicellular larger organisms. The body of the fungi made up of filamentous material, their body consist except for some unicellular fungi like yeast, body of the most of the fungi consist of long tubular filament that is long tube like filaments which sometimes may be septate that is they have septa divisions in them, sometimes they are non septate that is they do not have any divisions in them, sometimes they are uninucleated, sometimes they are multinucleated that is some have a single nucleus some have more than one nuclei. So the fungi are categorized into a different kingdom, we know that the organisms are in on the planet earth are classified into five kingdoms, fungi makes a separate kingdom among the organisms which is called the kingdom fungi, fungi have a specific body if they are not unicellular, they are multicellular which makes a filamentous appearance that is their body consist of filaments. These filaments are typically called hyphae when there is a group of hyphae present together in an area maybe in the soil maybe in the say root of a plant the collection of hyphae is called mycelium which makes the body of the fungus, they reproduce the fungi they reproduce both by sexual and asexual means normally they produce by asexual means as we know that they are eukaryotes, they carry out photos they carry out mitosis to produce their young ones that is the next generation but sometimes they also actually reproduce and their life cycle consist of some in part asexual reproduction and in part the sexual reproduction we have a look on their life cycle in a diagram. If you look at the diagram there are two cycles which are running side by side here n means the haploid or the half number of chromosomes and 2n means diploid or the double number of chromosomes. If we look at the side of asexual reproduction as they are labeled then we can see that after germination of the spores they produces mycelium that is body of fungi as we previously described that consist of various hyphae this is this have n number of chromosomes that is half number of chromosomes and they live like this for a longer period of their life then these mycelium they produces spores and for production of the spores they produces some spore producing structures these spore producing structures also have n number of chromosomes that is half number of chromosomes these structures then produces spores those spores germinate to make the mycelia again. So this is sexual reproduction life cycle is a life cycle which in which all the organisms that is all the forms of that particular fungus are haploid that is they have a half number of chromosomes but they can enter into the sexual reproduction sometimes whenever it is required by the environmental conditions what happened that we call this process a plasmogamy that is the cytoplasm of two cells is fused the filaments they comes together in specific area and the filaments of opposite mating types they produces fusion tubes with the help of these fusion tubes their plasma that is the cellular plasma they fuses we call it plasmogamy when the plasmogamy occur then that particular cell have two nuclei one from one cell and one from the other cell we call it a dikaryotic stage that is there are two nuclei present inside the cell and both are haploid both have n number of chromosomes after some time karyogamy occur karyogamy means we know that karyo word means that something related to nucleus after sometimes karyogamy occur and the result is the karyogamy means that the both the nuclei which are haploid present in that cytoplasm they are fused when they are fused they make a diploid nucleus which have two n number of chromosomes that is a say otherwise normal number of chromosomes though we know that most of the part of their life fungi lays in a haploid form then whenever the favorable conditions come the these diploid stage consists which have two n number of chromosomes carry out meiosis and they again produce some spore producing structures and because in this diploid stage meiosis occur we know that the result of meiosis are the cells which have a half number of chromosomes in each nucleus so the spore producing structures because they are produced by the meiosis in the diploid stage so they have a half number of chromosomes and when they make spores these spores also have a half number of chromosomes these spores again germinate to form the mycelia that is body of the fungus so this is how fungus carry out its life cycle.