Biology: The Diversity of Fungi

sporangium (plural sporangia)

Asexual reproduction is initiated by the formation of haploid spores in black spore cases called this. These spores disperse through the air and if they land on a suitable substrate (such as a piece of bread) germinates to form new haploid hyphae.

chitin

a tough semitransparent horny substance--the principal component of the cell walls of certain fungi

glomeromycete

almost all of this group live in intimate contact with roots of plants. They penetrate the cells of the root and form microscopic branching structures inside the cells.

ascus (plural asci)

at the tips of some of hyphae a sac like case forms called this

blastoclade

distinguished by some characteristic features, such as a distinctive structure called the nuclear cap that is found near the nucleus of blastoclade spores--the cap is formed by the spore's ribosomes. They live in fresh water or soil and some are parasites of plants or aquatic invertebrates.

key features of fungi

fungal bodies generally consist of filamentous hyphae, which are either multicellular or multinucleated and form large, intertwined networks networks called mycelia. Fungal nuclei are generally haploid. A cell wall of chitin surrounds fungal cell. All fungi feed by secreting digestive enzymes outside their bodies and absorbing the liberated nutrients.

spore

fungi develop these--haploid cells that can give rise to a new individual. They are tiny and extraordinarily mobile, even though they lack a means of self-proulsion. Produced in great numbers.

mycorrhiza (plural mycorrhizae)

important symbiotic associations between fungi and plant roots.

fungal reproduction

is varied and complex--asexual reproduction can occur through mitotic production of haploid spores. Sexual reproduction occurs when compatible haploid nuclei fuse to form a diploid zygote, which undergoes meiosis to form haploid spores. Both asexual and sexual spores produce haploid mycelia through mitosis.

major groups of fungi

major taxonomic groups--Chytridiomycota (chytrids)--Neocallimastigomycota (rumen fungi)--Blastocladiomycota (blastoclades)--Glomeromycota (glomeromycetes)--Basidiomycota (basidiomycetes)--and Ascomycote (ascomycetes)

chytrid (singular chytridiomycota)

most of this group live in fresh water, but a few species are marine. They have single flagellum on on end. The oldest known fossil fungi--more than 600 million years old.

hypia (plural hyphae)

one-cell thick, threadlike filaments. In some species, hyphae consist of single elongated cells with numerous nuclei--in other species hyphae are subdivided--by partitions called septa--into many cells, each containing one or more nuclei.

septum (plural septa)

partitions that separate hyphae into many cells.

ascomycete (or sac fungi)

reproduce both asexually and sexually. In asexual reproduction, spores are produced at the tips of specialized hyphae and after dispersal, develop new hyphae. During sexual reproduction spores are produced by more complex sequence of events that begins, in a typical ascomycete, when hyphae of different mating types come into contact.

basidium (plural basidia)

some of the hyphae in the fruiting body develop into club-shaped reproductive cells called this--that, like their precursor cells, contain two haploid nuclei. In each basidium the two nuclei fuse to yield a diploid nucleus that divides by meiosis and gives rise to four basidiospores.

lichen

symbiotic associations between fungi and single-celled green algae or cyanobacteria. Called fungi that have learned to "garden" because the fungal member "tends" the algal or bacteria partner by providing shelter and protection from the harsh conditions.

mycelium (plural mycelia)

the body of almost every fungus is this, which is an interwoven mass of one-cell, threadlike filaments called hyphae.

basidiomycete (or club fungi)

they produce club-shaped reproductive structures. Members of this phylum typically reproduce sexually.

rumen fungus (also neocallimastigomycota)

this group is anaerobic (they do not require oxygen) and reside mainly in the digestive tracts of plant eating animals such as cows, sheep, etc. Helps the animals digest plant tissue for nutrients.

zygomycete

this group lives in the soil or on decaying plant or animal material--such as soft fruit rot and black bread mold.