Saturday, August 8, 2009

Phyla of a Fungi



Hello. Today we will be talking about "Phyla of a Fungi". Phyla of a fungi can be divided into 5 divisions. They are: Oomycota, Chytridiomycota, Zygomycota, Ascomycota, Basidiomycota. Let's us look in deeper.

Oomycota

Oomycota is a phylum of filamentous protists containing over 500 species. The majority of these organisms are in the groups commonly known as water molds or downy mildew. "Oomycota" means "egg fungi", referring to the oversize oogonia which house the female gametes (eggs). Despite the name and their superficial appearance, oomycetes are not fungi. While some members of Oomycota are relatively harmless, some species are parasitic and negatively affect aquatic plants or organisms.

Oomycete cells differ from those of true fungi in that they have walls of cellulose and the amino acid hydroxyproline. They are heterotophic, either saphropytic or parasitic. Oomycetes can reproduce asexually, by forming a structure called a sporangium or zoosporangium. Inside these sporangia, zoospores are produced, first the primary zoospore and then the secondary zoospore, which is laterally flagellated. Their flagellum allow the zoospores to move rapidly through water. This type of germination is most common among aquatic and soil-dwelling species. Oomycetes may also germinate directly on the host plant by way of a germ tube. Organisms of Oomycota may also reproduce sexually, by direct injection of the male nuclei (sperm) into the oogonium. This type of reproduction is known as "gametangical copulation".
Chytridiomycota

The name is derived from the Greek chytridion, meaning "little pot", describing the structure containing unreleased spores.Chytridiomycota are the smallest and simplest fungi. They emerged soon after the Precambrian period, and are ancestors to all Fungi. The first Chitridiomycota were found in northern Russia. There are three orders within Chytridiomycota: Chytridiales, Blastocadiales, and Monoblepharidales. They are unicellular and is attached to food-source by rhizoid. Both zoospores and gametes of the chytrids are mobile by their flagella, one whiplash per individual. Asexual spores are zoospores. Sexual spores are zygotes. They are the most primitive fungi. They kill frogs. Furthermore, they rumen fungi, in other words, they help in the digestion of a fungi.
Zygomycota
Zygomycota, or zygote fungi, is a phylum of fungi. The name comes from zygosporangia, where resistant spherical spores are formed during sexual production. Approximately 1060 species are known. They are mostly terrestrial in habitat, living in soil or on decaying plant or animal material. Some are parasites of plants, insects, and small animals, while others form symbiotic relationships with plants. Zygomycete hypae may be coenocytic, forming septa only where gametes are formed or to wall off dead hyphae.

The common example of a zygomycete is black bread mold (Rhizopus stolonifer), a member of the Mucorales. It spreads over the surface of bread and other food sources, sending hyphae inward to absorb nutrients. In its asexual phase it develops bulbous black sporangia at the tips of upright hyphae, each containing hundreds of haploid spores. As in most zygomycetes, asexual reproduction is the most common form of reproduction. Sexual reproduction in Rhizopus stolonifera, as in other zygomycetes, occurs when haploid hyphae of different mating types are in close proximity to each other. Growth of the gametangia commences after gametangia come in contact, and plasogamy, or the fusion of the cytoplasm, occurs. Karyogamy, which is the fusion of the nuclei, follows closely after. The zygosporangia are then diploid. Zygosporangia are typically thick-walled, highly resilient to environmental hardships, and metabolically inert. When conditions improve, however, they germinate to produce a sporangium or vegetative hypae.

Ascomycota

The Ascomycota are a Division/Phylum of the kingdom Fungi, and subkingdom Dikarya, whose members are commonly known as the Sac Fungi. They are the largest phylum of Fungi, with over 30,000 species.

They have sexual spores, which are Ascospores, that are borne internally in a sac (ascus). Fruiting bodies that are called ascocarp that bear these asci. However, the asexual spores are borne externally as conidia. Some examples of Ascomycota are Saprophytes, Insect Fungi (Cordyceps sp), Plant parasites (Claviceps purpurea-ergot) & Industrial fungi (Yeast).

Basidiomycota


One of two large phyla that, together with the Ascomycota, comprise the subkingdom Dikarya (often referred to as the "Higher Fungi") within the Kingdom Fungi. More specifically the Basidiomycota include mushrooms, puffballs, stinkhorns, bracket fungi, other polypores, jelly fungi, boteles, and the human pathogenic yeast, Cryptococcus. Basically, Basidiomycota are filamentous fungi composed of hypae (except for those forming yeasts), and reproducing sexually via the formation of specialized club-shaped end cells called basidia that normally bear external meiospores (usually four). These specialized spores are called basidiospores. However, some Basidiomycota reproduce asexually, and may or may not also reproduce sexually. Asexually reproducing Basidiomycota (discussed below) can be recognized as members of this phylum by gross similarity to others, by the formation of a distinctive anatomical features(clamp connection), cell wall components, and definitively by phylogenetic molecular analysis of DNA sequence data.

Well, that's basically all about the divisions in a Phyla Fungi. More will come, sooner or later.

Cheers & Have a Good Day ahead!

Tuesday, July 28, 2009

Hellooooo, today i'm here to talk about mycology. (as usual. tsk.) It is actually a fasicinating subject if you are interested.

I'm here today to talk about the structures and lifestyle of the fungi.

Cell wall-

Rigid cell wall provides support for the Protoplasm of the fungal cell. The fungal cell walls are mostly chitin and glucan, while plant cell walls are mostly cellulose, plus liginin in the secondary walls.

Fungi are actually more alike animals than plants. Plants can make their own food through photosynthesis, while fungi cannot do so.

Fungi obtain their food via external digestion. They produce exoenzymes to digest food. They secrete them onto the surface which they are growing to digest their food. The fungi then absorbs the nutrients via the mycelia.

The fungi would then store their food as glycogen, just like animals!

Fungi however, has a lifestyle totally unique to its own kind.
Fungi are not dependent on light, and can occupy dark habitats. They also can grow in any direction. This is unlike animals and plants which require light!
Fungi can also invade the interior of the substrate with absorptive filaments!

Thats it for today, stop complaining! its already over :P

Monday, July 27, 2009

Hi all ! :D
So far, we've already explained what is fungi and it's characteristics. For today, it'll be a short one - Lifestyle of Fungi.

Fungi have three different lifestyles or ways that they obtain food:
saprobic, parasitic, and mycorrhizal.

Saprobic fungi are decomposers, or recyclers, that live on dead organic material from plants, animals, and other fungi. They can grow on a wide variety of food sources or specialists.

Parasitic fungi use living organisms as a food source, causing some diseases of plants and animals, including Dutch elm disease and ringworm. There are even fungi that attack other fungi like for example, Hypomyces.

Mycorrhizal fungi form beneficial partnerships with plants. The fungal hyphae interact with roots (mycorrhiza = fungus + root) and grow out into the soil, acting as extensions of the plant's root system.

Some fungi even have mixed lifestyles and can switch their eating habits!

Also, fungi are not dependant on light. This means they can occupy and live in dark habitats. This is because they are Heterotrophic. As said in yesterday's post, heterotrophic means that the fungi do not make their own food. This is because they do not have cholorophyll. Thus, fungi must absorb food from others. So, since they do not need the light to make food, they can live in damp and dark places.

That's all for now, we'll talk about more fungi tomorrow ! See you !

Sunday, July 26, 2009

Hey! Let's look into the characteristics of fungi as promised in the previous entry. To make it simpler, we will state the characteristics in ponit form for clearer understanding...

CHARACTERISTICS OF FUNGI:

1) All are eukaryotic-This means that fungi has nucleus

2) They are heterotrophic-They do not make their own food. Instead, they utilise pre-existing organic sources of carbon in their environment and the energy from chemical reactions to sythesise the organic compounds they require for growth and energy.

3) All are achlorophyllus- They lack chlorophyll pigments and are incapable of photosynthesis.

4) Many reproduce sexully or asexually

5) Some are unicellular- Some are made of one cell only.

So as you can see, Fungi are a special type of species. Unlike plants, they cannot make their own food. They depend on the body of other living things for energy. Stay tuned for the next entry where you will be more exposed mycology! Have a great day! :D

Saturday, July 25, 2009

Intro to Mycology !

Hi all! We are back!:)
Now that you know what Mycology is( the study of fungi for those who weren't attentive!) The first question to ask is...

What are fungi?? I’m sure you’ve had unpleasant experiences where you shrieked upon seeing a black-white fluffy growth on your bread, just like on this picture?
Photobucket
Totally ruined your appetite didn't it? The black-white fluffy growth is actually FUNGI!


A fungus (singular form of fungi) is a EUKARYOTIC organism that digests its food externally and absorbs the nutrient molecules into its cells by breaking down dead organic material.

P.S. The word in caps is pronounced as "u-carry-your-tic"
It comes from the word: Eukaryote. Eukaryote means "true nut," referring to the fact that eukaryotic cells possess an internal nucleus.

Fungi are part of the 5 kingdom. The 5 kingdom consists of Animalia (animals),Plantae (Plants),Protista and Monera. I bet you might wondering that why plants and animals are spelt in a "weird" manner in the 5 kingdom.
Reason is because, they are spelt in Greek! Cool eh?? In fact, all the terms under Mycology and Microbiology are spelt in Greek! By the way, did you know that all the other kingdoms in the 5 kingdom are either multicellular eukaryotes (multiple cells) or unicellular eukaryotes (single-celled), except fungi? Well, fungi are special because they can be both unicellular and multicellular eukaryotes!


Alright, that's all for this entry! The next entry will be on the characteristics of fungi!
So do remember to check in later!:))

Thursday, July 23, 2009

mYcOpSyChO mission 1!

MISSION 1

We, the mycopsychos of MB 0904, pledge ourselves to indoctrinate our readers to understand and love the study of mycology! muaaahahahahahhahaha *evil face*

Honestly, we are super duper nice people!!!

To the serious bit now...our aim is to post entries on mycology which is the study of Fungi, to raise awareness and have a clear understanding in this field.

Ok we gotta go for our beloved MICROBIOLOGY A lecture now! We'll come back soon!

Bybyeeeeeeeee! :D

Signing off,
The MycoPsychos (: