Biology Fungi

Hi, welcome back to www.educator.com, this is the lesson on fungi.0000

The basics of fungi as a kingdom, these are the characteristics of kingdom fungi.0005

Multicellular eukaryotes, they have that in common with plants and they have that in common with animals.0011

But what makes them more unique, cell walls made of chitin.0017

If we looked at other cell walls, like cell walls in plants, those are typically cellulose.0023

Then, if we talk about cell walls in bacteria, that is typically a type of glycan.0038

This is definitely unique to the fungi kingdom, chitin.0055

Chitin is one of the many polysaccharides that you can find naturally on earth.0059

You know obviously, cellulose is another polysaccharide, chitin a bit different.0065

Feed off of dead, decaying matter, or they are parasitic.0071

There are animals out there that feed off of dead, decaying matter.0074

They are those parasitic, the fungi classically are doing that.0076

Fungi in a forest, fungi in any environment, are helping to decompose what is in the ground, get it back into an organism,0081

and then it is a part of the food chain again, because there are animals that would eat the fungus.0091

And then, there are other fungus that eat fungus as well.0096

They typically digest first and then they ingest.0099

Let me explain, the average animal will ingest meaning put it into its body through the mouth.0103

Then, it will digest and afterwards break it down while it is in the body.0109

But the average fungi, this will secrete a substance outside of its body,0113

to break down the pieces of the organism into little tiny bits.0117

That they then can take in, because a fungus does not have the mouth,0122

it just wants to absorb those sentences through its cells.0126

Digest then ingest, and then fungi they reproduced asexually or sexually, a lot of fungi can do either.0130

With animals, you will see a lot more like they are doing one or the other.0138

Sexual reproduction is the typical way that animals do it.0143

But you will see a lot of asexual with fungi, even more advanced fungi.0147

The are more close related to kingdom animalia than plantae.0152

Not just in the sense that they are heterotrophic, meaning eating and in getting a food source0155

from outside and not making their own food.0160

But genetically, the genetics of you and a mushroom, sounds funny,0162

but you have more in common with a mushroom than you do with a tree.0167

Here is a variety of a fungi, a lot of these in this picture are club fungi, mushrooms, and their relatives.0170

Fungal structure, hyphae is the real common body part for a fungus.0179

Here is a fungal hyphae below the surface, this is the ground, this is soil.0189

And I know that you do not want to call these roots, but all of this,0194

these strands of cells that then can emerge through mitosis from under ground inside of a mushroom, all of these are hyphae.0199

One of them is a hypha but plural for a lot of them is hyphae.0219

These are strands of cells, if we zoom into them, here we are zooming into one little hypha strand.0225

Some of them, in certain species, have little walls between each cell which is kind of normal for multicellular organisms,0233

this is called septate because each of these is a septa.0242

The septa, they separate individual cells just like you would see in multicellular animal or plant.0251

But you have other ones like molds, are aseptae which is weird to think about0259

but it is just like one continuous long cell, with free floating nuclei.0269

They are not separated by cell walls made of chitin.0274

The other term for this is cinocidic, let me spell that nicer for you.0277

Depending on what source you are looking at, you will see either term aseptae lacking the septa or sinocitic.0289

Mycelium is the specific part of the fungus that is feeding off with the food.0298

With the mushroom, the mycelium would be the part that is actually in the ground, that is actually growing in the soil.0304

Whatever part of the fungus is imbedded in its nutrients source, that is the mycelium.0316

Spores are what are dropped out of the fruiting body.0324

Spores will land in the ground and they will make new hyphae strands.0332

They can grow into another fruiting body, speaking of fruiting body that is what this is.0340

Regardless of what fungus it is, if there is a section devoted towards making spores, it is known as a fruiting body.0350

These come from the fruiting body.0360

Depending on the type of fungus, it will be called a basidiocarp or an ascocarp, etc.0367

Reproductive strategies, as mentioned before, you got asexual and or sexual, in these kinds of organisms.0377

Fragmentation would be, if you cut apart the hyphae, you fragment it.0383

If you think it is broken off, it just will grow into two independent fungal organisms, that is the duty of a fungus.0389

Budding is something like this, here is a yeast, it is this tiny little fungus in a coat.0395

It can actually just bud, like a little baby will just come off of it, as if it is like bacteria dividing.0404

This would become a separate yeast individual, and then a lot of yeast do this.0411

Just a strict asexual development, just budding to make more yeast.0417

Spore production that is typically associated with sexual.0422

Keep in mind that spores can originate for asexual reproduction, but when you are talking about hypae fusing,0428

I will demonstrate that for you in a little bit’0436

Hyphae from two different fungi of the same species, two individuals, and then combining their cells to make a fruiting body.0437

You are then going to call the resulting gametes, if want you to call them that,0446

spores to make a new hyphae of the new organism.0452

I just wanted to show you this, that hidden inside of this leaf is a bunch of spores of a fungus.0455

You actually got a fungus using a plant body to continue its offspring.0461

The first group of fungi is zygomycota, this is a phylum of zygomysis, you can call them there molds.0471

Asexual production is common in molds, but they also can be produced sexually.0480

When sexual does happen, they form what are called zygospores.0485

Notice that the word zygo, the prefix to this particular group, they put that with spores.0489

Zygospores are result of sexual reproduction, when gametangia join.0496

Here is what they mean, you got little hyphae units,0501

here and here is the fruiting body growing out of these different kinds of molds.0504

Let us say that under ground, here is the ground, or it could be in fruit or in bread, you got hyphae of this one, we are going to call it the positive version.0509

Then you got hyphae from this other mold individual, that we are going to call the negative.0526

It is like saying male and female, they are opposite mating types and they are attracted to one another,0531

they will grow towards one another.0537

When they fuse, you then will have units with two haploid nuclei.0539

Because actually this is haploid and so is this.0557

When they come together, they will grow a fruiting body which will have a diploid section up at the top when those nuclei fuse,0562

and then meiosis will happen to make the spores that fall from out of here.0570

Once this spores land, guess what? New hyphae will grow and then they can make another fruiting body and just continues from there.0576

There is a term for this when you have fusion of hyphae but the nuclei do not quite fuse yet, it is called dikaryotic.0586

A lot of fungi will have dikaryotic units that will multiply, everytime that this goes to mitosis to form the fruiting body, there will be two nuclei in each cell.0595

Finally, up near the top, they will fuse, make a unit that is actually diploid and then they will do meiosis to make the spores.0607

Each of these sections here, they are called gametangia.0617

When this gametangia join, they will make what is going to be known as the zygospores.0622

The zygospore forms there and you get your fruiting body from that.0627

Stolons, we actually saw this word with plants.0632

It is horizontal growth that extends mycelium.0636

If this grows out like this, new fruiting bodies over here.0638

Mold can easily extend itself via the food source, getting its mycelium extended.0644

Rhizoids, they are like little roots for mycelium.0652

Depending on the fungus, little units that are helping to anchor it and get nutrients from its food source.0655

This is how this word with the ferns, the gametophyte generation of ferns actually has rhizoids on it.0664

Risopous is a common genus of zygomisis.0672

A lot of bread molds, fruit molds, they rise up to something.0676

Here is a classic example of mold on an orange.0681

Clearly, this orange has been sit around for a while, fungus spores got in it.0685

At first, when they first get in the orange, you cannot see them.0689

But once the mycelium has extended enough, you got enough fruiting bodies, this little grayish green fluffs on the top like that.0692

It is quite spread at that point.0700

Next up, ascomycota, also known as the sac fungi.0705

This is the largest phylum of fungi on earth, in individual source I looked in, it is about 30,000.0708

I have actually heard it is closer to 60,000.0715

Depending on the source, it is tens of thousands, lots and lots of ascomycetes.0719

I like to see a source with the list of all 60,000, that is a lot of species.0727

The majority of animal phyla do not have that many species.0733

These are very successful and extensive around the earth.0737

They make a structure called an ascus, the ascus contains sexual spores.0740

You can call them asco spores, you are just taking that prefix.0745

Conidiaphores produce conidia, and that is the term for the asexual units.0749

If you have a sac fungi making sac fungi from one parent, it is via these conidia that came from the conidiaphores.0754

Here is the sac, you are actually looking at the truffles.0765

I do not mean chocolate truffles, these are fungal truffles.0769

Grow underground, typically near trees on certain areas, and they are very valuable in terms of culinary pursuits.0776

Chefs will pay, sometimes, no joke, hundreds of dollars or pound for truffles.0785

The shavings and oils from them have a very rich earthy flavor to them, and it is used in these high end dishes.0791

I once had mac and cheese with truffle oil, it was definitely expensive but I got to do it, it was pretty good.0798

Within these ascospores, sorry this whole thing is an ascus, it produces ascospores.0804

If you were to take a cross section, you would see these units that have undergone meiosis.0815

You would see little spores, specifically they are called ascospores.0826

Within these little units, within the asci, little packages.0836

So an ascus has these little ascospores inside of it.0843

The whole thing, if we are talking about the whole entirety, it is called an ascocarp.0848

This specific unit within the ascocarp is called an ascus, and then the ascospores develop in the ascus.0859

From top down, ascocarp contains asci, plural for this asci.0869

In the asci have meiosis occurring to produce the ascospores.0878

When they get released, they can grow into more hyphae that is going to result in new ascocarps, etc, extending the sac fungi.0882

Acetymycota, the club fungi, they look like a club when you hold it and there is a fake top to it.0893

They are mushrooms, typically, they have club shaped reproductive structures.0900

Now, it is going out of the ground, you can actually get some of these things0906

growing out of just destroyed organisms, growing out of trees even.0910

They make a structure called a basidium.0914

You can actually call this a basidiocarp.0917

The fruiting body is another name for it.0929

Within it, you have basidiospores, specifically in the gills of the fungus.0931

Caps, you are looking at a cap right here.0936

There is a cap, underneath it, if you have ever eaten a mushroom cap, you have seen them,0945

they look little lines, like almost like little folders in a filing cabinet.0952

There are the gills, within the gills you have the spores that will exit out of it and land somewhere where there is enough nutrients.0959

The stype also called a stalk is what lifts the fruiting body up out the ground from the mycelium.0967

Mushrooms like this one and puffballs are common examples.0977

Puffballs look typically like just a little round ball that, if enough of wind hits it or something brushes against it, it will explode spores.0980

We are talking billions of spores and it would look like dust.0992

It is a really cool adaptation that allows it to send its stuff into the wind.0996

You got some pretty expansion, in terms where little babies will land.1000

This is called shell fungi growing out of this tree.1004

Sometimes, they benefit the tree.1013

In this case, the tree is doing all right, the mushroom is actually taking1014

probably carbohydrates and amino acids from the tree, as well as some moisture.1020

It can provide the tree with some nutrients like certain compounds of the tree would not naturally produce.1025

It is giving the tree back some stuff, if it was robbing it completely, it would not be beneficial to both.1034

The source or the fungus, if it dies off, the fungus is going to die off.1041

Deuteromycota, these are also known as imperfect fungi.1048

These are known as imperfect because there is no known sexual lifestyle,1051

unlike all the other phyla that I taught you about, those had at least some sexual version.1055

When hyphae from two nearby fungi combine, make that dikaryotic structure,1067

and having them fuse and making spores, this only does asexual.1071

A lot of yeasts are actually in this group.1076

Penicillin, the drug that was classically used to beat bacterial infections, not in use as much anymore,1080

because a lot of bacterial infections, do not die from penicillin these days.1086

They come from a genus of molds, actually a kind of deuteromycite called penicillium.1092

That is what you are looking at here.1100

So penicillin was the genus, here it is under the microscope.1102

By the way, there is a theory that perhaps deuteromycites do undergo sexual reproduction.1108

We just have not observed it yet.1116

It is hard to believe because you would think that somewhere, some of the scientist in some lab,1119

would have given enough time to say that there is the sexual life cycle, has not been observe yet.1123

Maybe it does not exist.1129

Benefits of fungi, neutralism is when you have a relation between two organisms where they both benefit.1133

Mutual benefit is what is going on there.1141

Mycorrhizae, that is a case where it is a fungal connection with plant roots.1144

Actually, there are theories that the majority of plants out there have these.1151

If you were to zoom in to a plant roots, here is the plant, you would see this extensive,1156

like looking in little fibers all around it, inserting themselves in part of the plant root.1165

What is happening with the mycorrizae is taking little water, taking little amino acids,1173

but it is actually giving the plant certain compounds that will help it do its thing.1183

They need to get something out of the situation, they can actually help the root do what it does better,1190

in terms of getting nutrients to the plant.1198

That is a mutualism going on under the soil.1201

Lichens is a kind of sac fungim like kind of ascomycete that has algae on it.1206

You got the fungus supporting the algae, the algae gets benefit out of that.1213

It gets a terrestrial spot where it can exist and it has a home there, cradled in that sac fungus.1219

But also the fungus is getting some carbohydrates out of the scenario, because the algaes do in photosynthesis.1226

There are at least 20,000 unique lichens that are out there.1231

The amazing thing is, here you got it on some granite counter, here it is actually growing in spores.1238

The amazing thing is that, you have so many different versions, some are called folios lichens1245

because they look like foliage, almost like leaves, like this one.1256

They come in such a variety of colors, I have seen ones that are even like purplish, orange, red, green even like blues.1258

There is amazing varieties of lichens, they are known as a bio indicator.1263

The reason why is, they are really susceptible to pollution.1275

They absorb a lot of compounds up there, there is excess pollution in the area, it will kill the lichens.1279

If you have any lichens that are incapable of growing, it is a sign that it is too polluted.1284

Actually a lot of lichens cannot grow in cities, the farther that you go into rural areas,1289

you are going to see them more common in the foliage, etc.1294

Food, we definitely have a fungi assisting us in producing certain foods, not just mushrooms.1300

I always see people eat mushroom, and people eat truffles.1308

But beyond that, certain cheeses like blue cheese, there are little bits of mold that lead to the blue part of the blue cheese.1311

It would not have its unique flavor without that.1319

Soy sauce is actually produced because of a fungus, there is yeast used to do that.1321

The production of citric acid, if you want a lot of citric acid fast to use in jams, jellies or certain candies,1328

like hard candies, there are fungi that will crank out citric acid with this chemical process.1334

You can get it into the food and it gives it that nice acidic balance with the sugar content.1342

Medicines, antibiotics -- of course, there is penicillin --1350

but beyond that, the majority of antibiotics we can get from different fungal strands1354

because they produce these compounds, so that bacteria does not kill them.1357

It is great that we can use that.1362

There is also medicines derived from fungus that actually will help initiate contractions in women.1363

If the baby is passed term and they want to get the baby out, it has been 42 weeks, which is way over 9 months.1371

They will inject a chemical into the womb that initiates the uterine contractions and gets labor going, that is from a fungus.1379

Also decomposition of organic matter in ecosystems, I hinted this earlier that is an important ecological purpose of fungi.1387

All those dead organisms that are in the soil, whether it is plant, animal, or whatever,1394

another fungi bodies, fungus that is alive will break that down.1401

It is a sacrophytic process or sacrocytic, I also heard, that means they are responsible for consuming dead, decaying matter.1405

That is what is a sacrophyte is.1416

Now fungal infections, this is the negative aspect of fungi for us.1419

Athlete's foot, you are looking at the fungus that causes athlete’s foot.1424

It looks unattractive, it burns, the more that you sweat in your socks,1429

the more that your socks gets moist and you do not change them, the more likely it is that athlete’s foot will develop.1435

Wash your socks, wash your feet, change your clothes, because fungi likes moisture.1442

Ringworm, this is not actually a worm, it kind of looks like a red circle that will grow on the body,1448

specifically in the skin, and it is a skin to skin contact that will get the fungus from one person to another.1457

Actually it is not a worm, it just looks like kind of like a worm in a ring shape.1462

Yeast infections, most commonly found within the vagina.1467

If you think about the vagina, in terms of an environment, it is moist, it is warm, it is dark in there,1471

and fungi like that environment, they will grow there.1476

It is not just in women, I mean the majority of people who get yeast infections are women,1480

but sexual contact of a male to a woman who has yeast infection can give him a yeast infection as well.1485

There are medications that will help get rid of that yeast infection.1490

Candidemia actually comes from a related species, candida is the genus of what causes most yeast infections.1496

But candidemia is a blood borne illness, that if it is not treated, this fungal blood problem can kill a person.1504

Aspergillus is typically inhaled, that particular fungus aspergillus can be in various foods.1515

It is possible they can exposed to it from contaminated crops, contaminated nuts, and it can cause aspergillusis.1527

It is actually a terrible infection from these aspergillus fungi.1537

Fungal meningitis, you can also get bacterial meningitis and viral meningitis.1544

This is when a certain fungus has infected the meninges.1549

The meninges are that wrapping around the brain and spinal cord, around your central nervous system,1556

helps insulate it, helps with blood flow in and out of there.1563

If that tissue gets infected and get swollen, because of this fungus, it can be deadly if untreated.1566

There are many more fungal infections, these are just some common examples.1574

Thank you for watching www.educator.com.1578