FUNGAL DIVERSITY

Fungi

They are essential for the well-being of most terrestrial ecosystems because they break down organic matter and recycle vital nutrients.

mycelia

networks of branched hyphae adapted for absorption

chitin

Most fungi have cell walls made of ________.

Septate fungi

Some fungi have hyphae divided into cells by septa, with pores allowing cell-to-cell movement of organelles

Coenocytic

______________ fungi lack septa.

haustoria

Some unique fungi have specialized hyphae called _______ that allow them to penetrate the tissues of their host.

Mycorrhizae

are mutually beneficial symbiotic relationships between fungi and plant roots

Ectomycorrhizal fungi

form sheaths of hyphae over a root and also grow into the extracellular spaces of the root cortex

Arbuscular mycorrhizal fungi

extend hyphae through the cell walls of root cells and into tubes formed by invagination of the root cell membrane

invagination

the action or process of being turned inside out or folded back on itself to form a cavity or pouch

pheromones

Fungi use sexual signaling molecules called __________ to communicate their mating type

Plasmogamy

is the union of two parent hyphae, mycelia.

heterokaryon

In most fungi, the haploid nuclei from each parent do not fuse right away; they coexist in the hyphae, this mycelium is called a

dikaryotic

In some fungi, the haploid nuclei pair off to a cell; such mycelium is

dikaryotic

contains two genetically distinct nuclei that coexist within a single cell without fusing

karyogamy

During ______, the haploid nuclei fuse, producing diploid cells; n + n = 2n.

Molds

produce haploid spores by mitosis and form visible mycelia

budding

Instead of producing spores, yeasts reproduce by

budding

simple cell division and pinching of “bud cells” from a parent cell

protist

The ancestor of fungi was an aquatic, single-celled, flagellated

nucleariids

DNA evidence suggests that fungi are most closely related to unicellular

choanoflagellates

animals are most closely related to unicellular

common flagellated unicellular ancestor

This suggests that fungi and animals evolved from a ____________ and multicellular arose separately in the two groups

zoospores

Chytrids are unique among fungi in having flagellated spores, called _________.

Chytrids

• These are the most primitive fungi.

• They live in water or moist environments.

• They are the only fungi with flagella (tail-like structures for swimming).

• Some can infect amphibians, causing disease.

Zygomycetes

• Includes bread molds (like the fuzzy stuff that grows on old bread).

• They produce zygospores (thick, resistant reproductive structures).

• Found on decaying food and organic material.

Glomeromycetes

• These fungi form symbiotic relationships with plant roots.

• They help plants absorb water and nutrients.

• Plants couldn’t survive well on land without them.

• Basically: fungi + plant roots = teamwork

Ascomycetes

• Also called sac fungi.

• They store their spores in asci (sac-like structures).

• Includes:

o Yeast (used to bake bread)

o Morels and truffles (fancy edible mushrooms)

o Many molds

These are the largest group of fungi.

Basidiomycetes

• Also called club fungi.

• Their spores grow on basidia (club-shaped structures).

• Includes:

o Mushrooms

o Puffballs

o Bracket fungi

These are the classic toadstool mushrooms you think of in forests

Zygomycetes

are named for they sexually produced zygosporangia

Zygosporangia

which are resistant to freezing and drying, can survive unfavorable conditions

asci, ascocarps

The phylum is defined by production of sexual spores in saclike ______(sexual spore-bearing cell), usually contained in fruiting bodies called

conidia

Ascomycetes reproduce asexually by enormous numbers of asexual spores called

conidiophores

Conidia are not formed inside sporangia; they are produced asexually at the tips of specialized hyphae called

Neurospora

is a model organism with a well-studied genome

Basidiomycetes

include mushrooms, puffballs, and shelf fungi, mutualists, and plant parasites

basidium

The phylum is defined by a clublike structure called _______, a transient diploid stage in the life cycle

recycling of chemical elements

They perform essential _________________ between the living and nonliving world.

Mycorrhizae

Live symbiotically in plant roots and are enormously important in natural ecosystems and agriculture

Endophytes

Lives inside leaves or other plant parts and make toxins that deter herbivores and defend against pathogens

Lichens

a symbiotic partnership of two separate organisms, a fungus and an alga

fragmentation, soredia

Asexual reproduction of lichen is by _______ or the formation of _______, small clusters of hyphae with embedded alg

mycosis

The general term for a fungal infection in animals is ________.