OK, here’s a new place. What is the difference between fungi and animals? How they process their food source?
Actually, the difference (in terms of definitions) isn’t as obvious as you’d think.
Fungi are:
*mostly multicellular (notable exceptions are yeasts)-so are animals (exclusively)
*heterotrophic (they don’t generate their own nutrition like plants) - so are animals
*eukaryotic (their cells contain membrane bound sub-structures) - so are animals
The main differences are:
- cell walls - fungi have them, animals don’t
- sense organs (or tissues) - animals have them, fungi don’t
- method of nutrient intake - fungi: absorption; animal: ingestion
- movement - animals move by cilia, flagella, or muscular structures/organs; fungi
don’t move under their own power.
Slime molds do (if slime molds are still considered fungi. I think there’s some debate over that.)
Crap. A slime mold fan has foiled my nice, orderly classification. Hopefully the sponge freaks won’t show up anytime soon.
I believe that the slime molds are now classified in Protista. They may have been moved lately though, I haven’t been a working biologist in ~10 years.
You’re right though, in that they do seem to overlap a couple of kingdoms.
A fungi has lots of amusing stories, always brings a couple six packs of good beer, and offers to help clean up.
An animal brings a case of Natty Bo, drinks it all himself, and throws up on your carpet after making a toga out of your spare linens.
In addition too what has already been posted, the three kingdoms* can be distinguished by their structural proteins. Plants use cellulose, animals use keratin and collagen, and fungi use chitin. In almost all organisms, the structural proteins are the most common proteins (usually about 30% by mass if I remember right)
There are five kingdoms total, but I decided to only mention these three as discussing the bacterial and archae kingdoms would probably lead to a major highjack
My understanding is that, while the creatures in the middle of each kingdom are pretty different from one another, the exact place to draw the boundaries between the kingdoms is somewhat arbitrary. Given that evolution has occurred from one kingdom to another, there are bound to be in-between critters like slime molds.
Daniel
Psst. Don’t you mean protista instead of archae, the latter being the nominal sixth kingdom?
Animals use chitin. Perhaps vertebrates use only keratin and collagen, but arthropods certainly use chitin.
As with many classifications, this all depends on who you ask. The current thinking is more along the lines of three Domains and umpteen Kingdoms (assuming one bothers with Kingdoms at all).
As for the OP, here is what the Tree of Life page on fungi has to say:
So a mushroom walks into a bar…
The “Five Kingdom” system was originally devised in response to the fact that organisms don’t fit neatly into the traditional “Two Kingdom” system of Plants (which included Fungi) and Animals. The problem is, slime molds don’t fit all that well into a Five Kingdom System either.
As Darwin’s Finch says, the most recent view is that there are Three Domains (a level higher than Kingdom), and, for those who still cling to the concept, dozens of Kingdoms just among the Eucaryotes.
The usual “Five Kingdoms” are Monera, including the procaryotic bacteria and blue-green “algae,” the Protista (or Protoctista) including unicellular eucaryotes; and the multicellular eucaryotes Fungi, Plants, and Animals.
A couple of recent findings have led to revisions to this system. For one thing, certain procaryotes called Archaea that were formerly considered bacteria turn out to be vastly different from them genetically, in fact at least as different as the eucaryotes are. This led to the proposal to recognize three Domains of Archaea, Bacteria, and Eucaryota.
Secondly, the Protista is a highly artificial category that includes some members that are closer to the Plants, some to the Fungi, and some to the Animals. Also, many of the groups among the Protista are at least as different from each other genetically as Plants and Animals are. Therefore, if you consider Plants and Animals to be separate Kingdoms, to be consistent you have to set up Kingdoms for each of the separate lineages of Protists, which leads to maybe 20 or so Kingdoms in all.
With regard to slime molds, there are actually two rather different kinds that are not closely related. Although they traditionally have been considered Fungi, they have also been considered Protists, but they should probably be in separate Kingdoms of their own (or perhaps together with some related unicellular forms).
That “Tree of life” quote gives rather short shrift to the zygomycetes. Being coencytic, these fungi consist of a single mass of protoplasm replete with thousands of embedded nuclei. The cytoplasm only differentiates into mononucleate cells when it’s time to make spores.