Members of the Kingdom Fungi act with bacteria to be the primary decomposers of organic matter on our planet.They break down organic molecules and make them available for recycling.

Characteristics- This kingdom is eukaryotic, mostly multicellular and like the algae usually reproduces asexually, although during times of environmental stress, these organisms will reproduce sexually. They have cell walls composed of chitin( a tough carbohydrate material found in fungi & the exoskeletons of crustaceans for protection).

    Biologist have in past classified fungi as plants, probably due to the fact that they were sessile ( stationary to one point most of its life) and seemed to be rooted. Fungi indeed are very different from plants. Below are several ways in which plants are different than plants.

Heterotrophic- Fungi obtain their nutrients by absorbing organic molecules from their surroundings, where as plants are green due to the presence of chlorophyll which allows them to be photosynthetic.

Filamentous Bodies- Plants are multicellular, but have different types of cells composing different types of tissues. Fungi have long slender filaments called hyphae, each having many cells and the hyphae are intertwined to form the  body and reproductive structures of the fungi.

Chitin- Plant cell walls are composed of cellulose, whereas fungi cell walls are composed of chitin. Chitin  is more resistant to bacterial decomposition than is cellulose.

Nuclear Mitosis- In plants the nuclear envelope disintegrates in prophase and re-forms in  telophase, so chromosomes are seperated to opposite ends of the cell before cellular division can take place.
In Fungi the nuclear envelope does not dissapear during the phases of mitosis, and chromosomes are seperated to opposite ends of the nucleus.

Phases of Mitosis
                                                    Quick Time® Movie of Mitosis
                                                Quick Time® Movie of Division of
                                                                       Chromosomes
 

    1.Interphase:
       The longest phase in which the cell is dormant except for the
       dispersion of chromosomes.
    2.Prophase:
       First stage of Mitosis where the chromosomes compact themselves
       from dispersed chromatin.
    3.Metaphase:
       Second stage of Mitosis where the chromosomes line up in the middle
       of the cell perpendicular to the poles.
    4.Anaphase:
       Third stage of cell division when the chromosomes begin to divide
       into two sister chromatids and go to opposite ends of the cell.
    5.Telophase & Cytokinesis:
       Final stage where the cytoplasm divides completely in to two, the
       nuclear envelopes reform, and the nuclei begin to reform resulting in
       two new cells.
Complete Description of Phases with Drawings

   Bibliography
   Definitions

    Fungi are well suited for absorbing nutrients.
        Most of what we see in looking at bread mold as well as others, is actually the reproductive structures of the fungi. Actually all fungi are made up of the following parts.
    Hyphae- these are long slender filaments which are composed of many cells. The cells are divided by septa, (a wall which is perforated and lets materials pass freely from one cell in a filament to another). Cell cytoplasm as well as organelles may pass into each cell from another due to the perforated septa.
    Mycelium- This is a collection of interwoven hyphae, in a tangled mass, which basically makes up the body of the fungus.
    At the tips of the hyphae, fungi secrete  powerful digestive enzymes that break down organic matter into molecules. The fungi then absorb these molecules and use them for energy.

Fungi are economically important.
    1) Yeast - produce CO2 gas while metabolizing carbohydrates so bread will rise.
    2) Fungi provide teh flavors and aromas of specific types of cheese.
     3) Many antibiotics are developed from various fungi.
                a) Cyclosporine is a compound derived from fungi that live in the soil. This drug supresses the reactions of the immune system that cause rejection of transplanted organs.

Fungal Reproduction

    Spores from sexually or asexually in reproductive structures at the tips of the fungal hyphae. The reproductive structures extend high above the food source so that air currents can carry the spores to a new environment. These spores are haploid and are formed mitosis during asexual reproduction. Fungi as well as protist undergo sexual reproduction during times of environmental stress. Sexual reproduction will be explained during the phylum characteristics listed below.

    The one characteristic that seperates fungi from all other multicellular organisms is that their cells share nuclei. Three of the fungal phylums are classified according to the way nuclei from different individuals are sorted in fused hyphae during sexual reproduction. The other phylum contains fungi in which sexual reproduction is rare if ever observed.

    Zygomycota- This phylum refers to the thick-walled  sexual structures called zygosporangia that occur within this group. This fungi group consist of many who live in the soil and feed on decaying plant and animal matter.
    Asexual reproduction occurs most often, where haploid spores are produced in specialized hyphae that end with spore-producing structures called sporangia.
    During Sexual reproduction, two hyphae from opposite mating strains fuse. Complete septa form hehind the tips of the touching hyphae forming a chamber containing numerous haploid nuclei. Then the haploid nuclei fuse to form diploid nuclei. The newly developed structure contains a number of zygotes and is protected in a tough dormant zygosporangium. The zygotes in the zygosproangium undergo meiosis when conditions become favorable again and the zygosporangium germinates producing sporangia. Haploid spores develop within the sporangia and are scattered by air when the sporangia ruputures.

      Ascomycota-Members of this phylum are so named for their reproductive structure, a club-shaped, saclike structure in which haploid spores are formed called an ascus . Asci usually form within the tightly interwoven hyphae of a complex structure called an ascocarp.
There are many different types of Ascomycetes that have played a significant role on our planet among them are the following.
    1) Endothia parasitica- around 1890 brought the disease called chestnut blight and destroyed virtually all the chestnut trees within a few years.
    2) Ceratocystis ulmi- brought on the dutch elm disease
    3) Very useful yeast also belong to this phylum. Although there are some yeast like Candida which are human pathogens. Candida is a common source of thrush.
    4) The flavorful morels and truffles also are found in this phylum.

Sexual and Asexual reprodruction of the Ascomycota group is very similar to the zygomycota group. The main difference is that the specialized spores which are produced are called Conidia.

Basidiomycota- is the 3rd phyla of fungi which show sexual reproduction. These fungi are probably more familiar to you. Most of the mushrooms we know of are found within this group. Besides the mushrooms, toadstools, puffballs, jelly fungi, and shelf fungi make up this group.
These organisms are named for their club-shaped sexual repriductive structure called the basidium. Here asexual reproduction is rare.
Under proper conditions, underground hyphae grow upward adn weave together to produce a mushroom, the reproductive structure of fungi. This structure consist of a stalk and cap. The underside of the cap is lined with thousands afo club-shaped reproductive cells called basidia. Through a series of fusion and meiosis each basidium produces spores, that are released and germinate into new hyphae.

Deuteromycota- ( Fungi Imperfecti)
    This phylum contains fungi in which sexual reproduction has not been observed. Organisms in this phylum are classified according to their asexual reproductive structures.
Penicillium- and other fungi in this group are used in the development of antibiotics.
Cheeses- other organisms in this group give flavors and aromas to cheese and other products.
Aspergillus- is a species used forfermenting soy sauce and for the production of citric acid.
Human diseases- most of the fungi that cause human disease, like ringworm, athlete's foot are also included in this group.

    Many fungi are involved in symbiotic relationships. In most cases the fungas contributes the ability to absorb mionerals and other nutrients and the photosynthetic partner contributes the ability to use sunlight to power the building of organic molecules.

Lichens- grow on trees and in moist wooded areas. The fungal partners are ascomycetes and the photosynthetic partner is hidden between layers of the hyphae. The fungi provides minerals for the photosynthetic partner and the photosynthetic partner provides organic compounds for the ascomycete to decompose. Algae are usually involved in this photosynthetic relationship. Lichens may be found in all types of environments. Many lichens are able to carry out nitrogen fixation( returns useful forms of nitrogen to the environment)
    Sensitivity to pollution-

Mycorrhizae:

    This is a symbiotic relationship with fungus and plants. The fungus transfers phosphouus and other minerals to the plant, while the plant supplies carbohydrates to the symbiotic fungus.
    Endomycorrhizae- fungal cells that extend into the cells of the roots and form swellings. The fungus that is involved is usually a zygomycete.
    Ectomycorrhizae- fungal cells do not penetrate the cells of the root, but rather wrap around the exterior. These are economically important due to the fact that they grow in the temperate regions where pines, oaks, beeches and willows grow. Usually basidiomycetes are involved with this association.