 Say you find this stale piece of bread on your kitchen counter one night and it doesn't really look right this bread because it has all these dark colored green spots everywhere and as more days go by you notice that these spots kind of grow and spread all over this bread and soon your bread turns into a horror show like this. So what are these things, these green black patches all over your bread? Well these are fungi, heterotrophic non-photosynthetic eukaryotes with cell walls made up of chitin and these fungi they got on this bread through something called spores, spores that landed on this bread and grew up to become fungi and then these grown-up fungi will eventually produce more spores and they will go ahead and grow somewhere else but how does all of this really happen? Well that's exactly what we're going to find out in this video. The life cycle of a typical fungus is quite interesting, most fungi start off as asexual or sexual spores. Now we're going to be talking about these types in more details in some time but let's focus on the spores for now. So these spores they are tiny reproductive particles which are super resistant to harsh environmental conditions. When the conditions become favorable then these spores will start growing into new fungi. Now these growing fungi they will develop these tube-like filaments called hyphae, the singular form is called a hypha. Now these hyphae will eventually form a network like this, an entire network of hyphae and this network is called a mycelium and for this to happen properly these fungi will need a lot of nutrition. All this nutrition leads to the growth of the fungi and once this fungi is all grown up and mature they begin their reproductive stage which in many fungi usually occurs in two cycles an asexual cycle and a sexual cycle. During the asexual cycle the most common mode of reproduction is through the formation of asexual spores which are produced via mitosis. So let's take a closer look at some of the examples we have over here. A few examples of such asexual spores are conidia, conidia and sporangiospores. Conidia are produced in chains at the tip of the hyphae so this blue part you can see this is the tip of the hyphae and these are the chains of conidia so these dotted structures are the spores or the other conidia. Sporangiospores on the other hand are formed inside an enclosed structure called the sporangium. So this enclosed structure right over here this is called the sporangium. The plural form of this is called the sporangia. So these sporangiospores are formed inside these enclosed structures or these sac-like structures called sporangia and you can actually see this feature in certain fungi only. Now some fungi don't really need spores to reproduce asexually. Asexual reproduction in fungi can be accomplished in a variety of different methods too. For example unicellular fungi aka yeast they can reproduce asexually via binary fission as well as budding. In binary fission a yeast cell splits into two by simple cell division. Meanwhile in budding an outgrowth or a bud appears on the yeast cell which eventually detaches and grows into a new yeast cell. So this bud right here will give birth or give rise to a new yeast cell. Now there's another form of asexual reproduction which is seen in some fungi and it is called fragmentation. Now in fragmentation what happens the hyphae this is a real not that of a great picture but this is a hypha and what happens in fragmentation is that the hypha kind of breaks or fragments into separate pieces kind of like this. So this is a separate piece this is a separate piece and each of these fragments or pieces will give rise to new fungal colonies. So this is another form of asexual reproduction. Okay so now that we have covered the whole asexual cycle and the different methods involved in asexual reproduction in fungi let's move on to the sexual cycle now. Sexual reproduction in fungi takes place in three major steps plasmogamy, cariogamy and meiosis. Now other than meiosis these other two terms sound a little fancy so let's break them down. Generally sexual reproduction in an organism is characterized by the fusion of two haploid or n cells to form a diploid or two n cell. It basically means that we go from two cells with one set of chromosomes each to one cell with two sets of chromosomes. That's what n stands for n stands for the number of chromosomes so these cells they have only one set of chromosomes and this diploid cell over here it has two sets of chromosomes. Now in fungi this fusion takes place in the first two steps that is plasmogamy and cariogamy. Plasmogamy translates to union of cytoplasm and that is exactly what it is. During plasmogamy only the cytoplasms of the two cells fuse together while the haploid nuclei remain free so we end up with one cell which has two free haploid nuclei but mind you they are not fused yet. Now in many fungi like mushrooms this cell remains as it is for quite some time just this one cell with two free haploid nuclei inside because these nuclei they don't fuse immediately and since they're not fused we cannot really call this cell a diploid cell or denote it as two n so instead we call this condition as a dicharion and we denote this cell as n plus n so and this intermediate phase where we see this n plus n condition or this dicharion condition this phase or this stage is called the dichario phase and it's an intermediate between the plasmogamy stage and the karyogamy stage. After the fusion of cytoplasms naturally the next step is the fusion of nuclei that is karyogamy. Once this fusion is complete it's going to give us a diploid cell or a two n cell and this diploid or two n cell is called the zygote. Karyogamy is then followed by meiosis so this diploid zygote will now undergo meiosis and give haploid daughter cells. These haploid daughter cells then become the spores or they develop into spores inside spore producing structures like these fruiting bodies of mushrooms. Oh and these spores are sexual spores because they are produced through the sexual cycle. Now some examples of sexual spores include besidio spores and asco spores by the way besidio spores is the spores that you find in mushrooms. All of these fungal spores both the sexual and the asexual spores they are then dispersed into the air and they remain as it is till they find a suitable place and environment to grow just like our beloved bread over here. Our bread over here posed as the perfect place for the spores to grow so they did and that is what the life cycle of a fungus really looks like.