Hi. It’s Mr. Andersen and in
this podcast I’m going to talk about fungi. Fungi is a pretty diverse group. It’s things
that you’re familiar with like a mushroom. But it’s also things that are much smaller
than that like a yeast which are going to be single cell fungi. And they’re also going
to form sometimes symbiotic relationships. So lichen for example is a symbiotic relationship
between a fungi and then an algae. And so not only do they breakdown and decompose material,
but they’re also going to serve another role. Working symbiotically with both algae and
then plants to allow them to function better. And so basically if we look at their phylogeny.
So this is the eukaryotes. So were going to talk about things now that have a nucleus
and have organelles. And you can find here that here’s our fungi. In other words when
we try to classify all eukaryotes, we’re going to put them right here. If you look at animals,
animals are going to be right here. And so what does this mean? Well we’re going to share
more recent common ancestry with fungi than we are with plants which are going to be way
back here. Because we put green plants way over on this side. And so we probably have
more in common with a fungi, especially the way we live our life than we do with green
plants. But we’re not directly related to them. This is more in to the phylogeny of
the actual fungi. And again we get this from the tree of life project. And so you can see
that we have this break off like this. And there are monophyletic groups. In other words
there’s going to be some groups that you should know because we know that these things all
share common ancestry and they’re one group. And so there are going to be five of those.
Chytridiomycota, zygomycota, glomeromycota, ascomycota and then basidiomycota. And so
these are ones that you do need to know because they’re monophyletic. And they’re important
when we’re studying biology. But before we get there let’s get to the characteristics
of fungi. Well they’re eukaryotic. So they’ve got a nuclei and organelles. They’re heterotrophs.
They originally were classified as plants and you can see why. It almost looks like
a plant. And they don’t move. They don’t run around like animals. And they also have these
root like structures that look like plant roots. And so we used to classify them as
plants, but they’re not. They eat material. And they’re going to digest material. I’ll
show you some cool examples of that in just a second. They have cell walls. So that separates
them from us. Also the fact that they don’t move. And the cell walls are made of a polysaccharide
called chitin. The exoskeleton of insects are made from that similar structure. Most
of the inside of the structure is actually going to be filamentous. In other words it’s
made of filaments. And so this would be the filaments in a mushroom. You can see these
thin little filaments. You can see the cell wall going around the outside of it. But they’re
not going to have any true tissues. In other words they’re not going to have, for example,
a muscle tissue or nervous tissue. It’s just going to be a group of these hyphae they call
these. That’s what these filaments are called, over and over and over again. And so even
if we were to look in here to these fruiting bodies of these mushrooms, we’d find that
they’re hyphae just packed together really, really tightly. Or if we were to look at the
roots of them, those are going to hyphae absorbing nutrients. And so those are some of the characteristics
shared by all fungi. They’re all heterotrophic. And so if you see one growing out of this
tree or this rotting tree, they’re digesting the material inside there and they’re eating.
And you can see here that this mold, which mold is kind of a term that just means fast
growing fungi, you can see this mold is breaking down this fruit. And if you’ve ever had athletes
foot you’ve been infected by a fungus as well. And so this right here is a fungus growing
in between the toes. And it’s hyphae will actually grow into the tissues of the person’s
foot. It secretes an enzyme. Then it digests that material inside. And it’s really painful
because it’s starting to digest the nerves on the outside of the foot. And one of my
favorite fungi of all is this anthrobotrys. Basically what they do is you can see the
hyphae that they’re growing here. But they’ll make these tiny little rings. And then when
you have a worm like this. This is called a nematode worm. Basically if the nematode
worm starts to swim through this ring, it will cinch tight on the nematode worm. It
will grab a hold of it. And then it’s going to digest it from the outside in. And so this
is an animal eating fungi. And so what could be much cooler than that. How do they reproduce?
Well they do reproduce a lot of the time asexually. And so when you have mushrooms just continuing
to grow out and out and out and out. And they can grow relatively quick, that’s going to
be asexual. But then they can also have a sexual phase as well. And so the spores that
come out of a puff ball like this are usually going to be asexual spores that can spread
to an area where there’s a little bit of water, some food and they can start growing. But
there’s also sexual portions. So these were formed through a sexual process. If we look
at this mushroom right here, basically what you get are, this would be a basidiomycetes.
Basically you’re going to have spores that fall down. You get the growth of a new mushroom,
but then we can have sexual reproduction producing more spores. And so there’s a variety of ways
they reproduce. Like I mentioned at the beginning, there are five important phyla that you have
to know when it comes to studying fungi. And I classified them from A to Z. This is just
a quick way that I remember it. So we’ve got A, B, C and we’ve got Z over here. So we go
from A to Z. A, B, C and then we’ve got G in the middle and the G can stand for um,
Golly, aren’t those fungi cool? Because these ones are going to be really cool in just a
second. And so let’s go from A to Z. So the first ones are the ascomycota. Ascomycota,
the asco or the ascus, that’s what ascus means. It means cups. So ascus means cup fungi. Or
sac fungi. And you can see right here this is that sac. And then the spores are going
to form on the inside of that. And that’s why we call it the ascomycota. Why are these
important? Well this is my favorite fungi of all. This is the morel. We like to go hunting
them in the spring. They taste delicious but they’re really hard to find. You’re looking
right here at the sexual portion of that. But you can see these sacs on the inside.
Or the sac right here. But ascomycota are also important. So penicillin is a fungus
or an ascomycota that is going to make a lot of the antibiotics that we have. And so they’re
important for that. If we look at basidiomycota is the next one. And so that’s the B. Basidio
comes from the word basidium, which means club. And you can see that on the underside
of a mushroom they’re going to have these little gills. But if we zoom in closer we’re
going to find these club like structures. And each of those club like structures is
going to form spores. We’ll have four spores that are found on this basidium. And that’s
where the name basidiomycota comes from. It’s club fungi. And so what are the big ones?
These are going to be the mushrooms that we think of when we think of fungi. Those are
going to be basidiomycota. If we look at these two together sometimes we would say these
two share common ancestry, ascomycota and basidiomycota. And we sometimes call these
the higher fungi. What’s next? Next is the C. So that’s going to be chytridiomycota.
And these are going to be sometimes referred to as the chytrids. These used to classified
as protists. And the reason why is that they have a flagellated stage where they’ll actually
swim around. We now know that they’re true fungi. You’ve read about these in the news
because we’ve seen on the planet huge increases in deaths of frogs. And a lot of those are
related to chytrid fungi that are infecting the frogs. Alright, let’s go to the G then.
So the G stands for the glomeromycota. Glomeromycota are very important because what they’ll do
is they form a symbiotic relationship with plants or a plant symbiosis. So what we have
are these mycorrhizal relationships. And so this right here is the root of a plant. But
you can see the fungi growing inside it. And almost all plants, in other words every plant
that we look for has these relationships between the glomeromycota and their roots. What does
that give them? Well that gives them increased surface area and it allows them to take in
more water. And then they give these fungi a place to live. And so it’s a great relationship
for both the fungi and for the plant. And then the last one is going to be the zygomycota.
Zygomycota, its name comes from the zygosporangia which is going to be this resistant structure
where the spores are actually formed. It will rupture and then we get this hiss as the spores
are spread out. If you look at that, a bunch of them together look like that. And a whole
bunch of them together are going to look like this. So this is a bread mold, zygosporangia
that you’re familiar with. And so basically what happens if you leave some bread out,
one of these spores is going to land on it and were going to get the growth of this fungus.
What’s the fungus eating? It’s eating the bread because that’s what they do. They’re
heterotrophs. And so can you remember those five important phyla of fungi? Ascomycota.
Basidiomycota. Chytridiomycota. Glomeromycota. And zygomycota. And they’re all just different
types of fungi. And fungi serve a huge roll on our planet. They breakdown material when
it’s dead and dying. They recycle those nutrients, but they also form these symbiotic relationships
with plants and algae. And I hope that all is helpful.