Quizlet Vocabulary Game, M4
M4 Recap Blog Post at Sahm-I-Am
Mold! (blog post at SAI cont.)
• Great drawings and explanation of the Life Cycle of a Mushroom
This post covers only the first few pages of Module 4, but it is looong since I wanted to cover it well.
So this will be Part A, the introduction, and Part B will cover 3 of the 6 phyla in more detail. Part C will cover the last 3 phyla in this module.
There's a fungus among us! =)
(1) p. 97-101a, General Characteristics of Fungi
Although mushrooms are the most common fungi, there are many other kinds as well. Some fungi are pathogenic (disease-causing), but there are also helpful fungi: some fungi are used in making cheese, others are used in baking, and even some in medicine.
Most fungi are multicellular; a few are single-celled. But whether multicellular or unicellular, their cells are all eukaryotes (each cell having membrane-bound organelles, each organelle performing a particular job). Their cells usually have many nuclei.
Most of the organisms in this kingdom are heterotrophs (can't make their own food).
Some of these heterotrophic fungi are parasitic (feed on living matter), but most are saprophytic (feed on dead matter). The saprophytic fungi are decomposers that promote the decay of once-living matter. Otherwise, leaves would pile up each fall year after year, not to mention dead animals, and other things that decompose.
►(Listen or Read this 2-minute Creation Moment with Ian Taylor)
Saprophytic or parasitic, they both digest their food outside of their bodies. They secrete a chemical onto the food that digests the food before it is ingested (eaten). The digested food is then absorbed into the cell of the fungus.
Extracellular (outside the cell) digestion can be beneficial to other organisms that can often absorb some of the nutrients before the fungus has a chance to absorb them.
♦Read How Fungi Get their Food
In addition to other various means of reproduction, the one means of reproduction all fungi have in common is by making spores.
Most fungi are multicellular, and will grow a specialized structure for that particular type of fungus for the purpose of producing spores.
For example, a mushroom has basidia on which their basidiospores form. (see image)
A spore print (see image) can be made by laying a mushroom cap on paper for several hours or overnight, covered by a bowl or jar to prevent air currents from disturbing the spores.
Here is a video of a puffball mushroom's spores. Its spores can be harmful if breathed in. They have a hole in the top and the spores puff out like smoke from a chimney. =)
The general structure of a mushroom is easy to see. There is the cap, which has the gills underneath (where the spores grow), and the stalk which is called the stipe.
This is all called the fruiting body. (see image)
What is not seen is actually the most amazing. Some may not realize a mushroom's main structure is underground.
It kind of looks like a whole bunch of tangled roots.
It typically is ten to twenty times larger than its stalk, but I've read that it can be as large as a soccer field!
The mycelium are not roots.
It does not pull nutrients and water from the soil (like roots do) to be transported to the rest of the plant because the mycelium is the main part of the plant. The mushroom's stalk and cap exist only at a certain stage, and are just an extension of the fungus's main body - the mycelium.
If you think about the fruit on a vine or tree, you can easily understand that the fruiting body is just something that grows periodically from the mycelium.
►See image of septate and non-septate hyphae. (source)
Nonseptate hypha looks like one long cell. There are no walls.
Both types of hyphae (hi' fee) have nuclei which are represented by the dark spots in the hyphae.
Remember that protists and monerans have cells that group together in colonies, but the cells do not exchange cytoplasm. Plants and animals are multicellular, but their individual cells are completely separate and do not exchange cytoplasm.
But in kingdom Fungi, the cells are not completely separate.
In the video, she says coenocytic threads. This is the same as nonseptate.
There are many different hyphae that perform different tasks. If a hypha is part of the mycelium (the part that grows below the soil), it is called a rhizoid hypha.
The job of rhizoid hyphae is to support the fungus and digest the food. These hyphae are considered the main body of the fungus.
An aerial hypha is not embedded in the main body of the fungus, and as its name implies, it sticks up in the air. It looks like a stem.
Aerial hyphae can do one of three things:
(1) absorb oxygen from the air
(2) produce spores
(3) asexually reproduce to form new filaments (hyphae)
♦If an aerial hypha asexually reproduces more hyphae, it is called a stolon (see image) -- a runner that grows along the ground, producing more offspring.
♦If an aerial hypha produces spores, it is specified as a sporophore.
Sporophores can be:
(A) a sporangiophore (see image) if its spores are formed within an enclosusre,
(B) a conidiophore (see image) if the sporophore's spores are not formed within an enclosure.
►(Source of images - scroll up)
►(Something silly to help you remember:
"Angie" will form spores in an enclosure. A con who is an idiot will not form spores in an enclosure.) I did warn you it was silly! lol.
Not all fungi have all these structures, however.
►Awesome diagram of what bread mold looks like up close.
If a fungus feeds on a living organism, a hypha can actually enter the cells of the living organism and draw nutrients directly from the cytoplasm of the living organism's cells. This kind of hypha is an extension of the mycelium and is called a haustorium (haw stor' ee uhm) (see image, source)
Since it feeds on a living host, this kind of fungus is parasitic.
Now that you are more familiar with the terminology, watch this video of how fungi obtain food. Listen for the different kinds of symbiosis that you learned in Module 3.
(2) p. 101, Reproduction in Kingdom Fungi
►All fungi reproduce by making spores. Some fungi also reproduce in other ways, as well.
♦The sexual reproduction involves structures called fruiting bodies, as a result of compatible hyphae.
Once the fruiting body is formed, it grows out of the mycelium and releases its spores. The mushroom is just part of the fruiting body of the mycelium of a type of fungus.
♦Some sexual reproduction does not lead to a fruiting body; it just produces a new hypha.
Time lapse of a fruiting body:
♦Asexual spore formation is accomplished by a hypha that becomes either a sporangiophore or a conidiophore.
♦There are other means of asexual reproduction that does not involve spores. These involve hyphae cells in the mycelium that cause the mycelium to grow. Also the cells within a stolon will reproduce asexually, causing the stolon to grow. The stolon will reproduce into hyphae that will form a new mycelium of a new fungus. This is repeated, often causing long chains of fungi, all linked together by stolons.
(3) p. 102, Classification in Kingdom Fungi
There are six phyla in kingdom Fungi, and as I read these and sounded out the pronunciations, I kept seeing "mycota" on the end. My coat... And then more words came into my mind.
►Here are some silly phrases to help you remember the phyla in the kingdom Fungi:
Basidiomycota (buh sid' ee oh my koh' tuh) Like a bus city o(n) my coat.
Ascomycota (ask' uh my koh' tuh) Ask-a my coat!
Zygomycota (zye' goh my koh' tuh) Zygo, my coat. (Who names their coat?)
Chytridiomycota (kye trid' ee oh my koh' tuh) Kye tridd-y o(n) my coat.
Deuteromycota (doo' ter oh my koh' tuh) Dude, yer o(n) my coat! (my favorite one)
Myxomycota (myk' so my koh' tuh) Mike, sew my coat. (He'd have to after all the people who have been on it, even a city of buses!)
I added the pronunciation marks the way the man pronounces it on the multimedia CD, which is different than the way it is written in your text book. However, just practicing and getting familiar with one way of pronouncing these is more important than which pronunciation you choose.
After practicing the pronunciations so you will recognize them, sometimes pronounced a little differently in this video, watch this overview of kingdom Fungi.
Part 1 Skip up to 0:50.
Part 2 Ignore the part near the end about evolution. =(
More at Module 4, Part B.