Chapter 29: The Fungi

Plasmogamy

________ occurs with the fusion of two hyphae of different mating types.

Lichens

________ have three main forms: crustose, foliose, and fruticose.

Hyphal branches

________ called haustoria penetrate plant cells and obtain nourishment from the cytoplasm.

Meiosis

________ produces four haploid nuclei that become basidiospores.

Fungi

________ cause many important plant diseases, including brown rot, corn smut, and wheat rust.

Flagellate spores

Chytrids, or chytridiomycetes, produce ________ at some stage in their life cycle.

Lichen

A(n) ________ is a combination of a fungus and a photoautotroph (an alga or cyanobacterium)

structural characters

Based on chemical and ________, fungi are classified, along with animals and choanoflagellates, as opisthokonts.

Ascomycetes

________ produce asexual spores called conidia; they produce sexual spores called ascospores in saclike asci.

chytrid gametes

Like animals, some fungi have flagellate cells- for example, ________ and spores- and the flagellate cells propel themselves with a single posterior flagellum.

Basidia

________ develop on the surface of gills in mushrooms; mushrooms are a type of basidiocarp (a fruiting body)

n + n

The fungi enter a dikaryotic (________) stage in which each new cell formed has one nucleus of each type.

ectomycorrhizal fungi

Some ascomycetes and basidiomycetes are ________ that form mycorrhizae when their hyphae coat tree roots, but do not penetrate the root cells.

sexual reproduction

In ________ hyphae of two different haploid mating types form gametangia.

Glomeromycetes

________ form endomycorrhizae with roots.

Karyogamy occurs

________, producing a diploid zygote nucleus.

Biologists

________ use the yeast Saccharomyces cerevisiae and other fungi as model organisms for research in molecular biology and genetics.

multinucleate spores

They reproduce asexually with large, ________ called blastospores.

opportunistic pathogens

Fungi are ________ in humans.

Zygospores

When ________ germinate, each hypha develops a sporangium at its tip.

fungus

The ________ may provide the photoautotroph with shelter, water, and minerals.

basidiospores

When ________ germinate, they form haploid primary mycelia.

Chytrids

________ reproduce both asexually and sexually.

Hyphae

In some fungi the ________ are coenocytes that form an elongated, multinuclear cell.

Spores

________ are released and develop into new hyphae.

Mycorrhizae

________ are mutualistic associations between fungi and the roots of plants.

animal cells

Microsporidia, currently classified as zygomycetes, are opportunistic pathogens that penetrate and infect ________ with their long, threadlike polar tubes.

septa

In most fungi perforated ________, or cross walls, divide the hyphae into individual cells.

endomycorrhizal fungi

Because they extend their hyphae into root cells, glomeromycetes are ________.

diploid thallus bears

The ________ zoosporangia that produce diploid zoospores and resting sporangia in which haploid zoospores form by meiosis.

recombinant nuclei divide

The ________ by mitosis, producing eight haploid nuclei that develop into ascospores.

fungus supplies

The ________ water and nutrient minerals to the plant, and the fungus obtains organic compounds from the plant.

organic compounds

Most fungi are decomposers that break down ________ in dead organisms, leaves, garbage, and wastes into simpler nutrients that can be recycled.

Haploid thallus

The ________ produces two types of flagellate gametes that fuse.

Plasmogamy

________ occurs, and nuclei are exchanged.

Meiosis

________ produces recombinant haploid zygospores.

n + n

A dikaryotic (________) stage occurs in which hyphae form and produce asci and an ascocarp.

Fungi

________ are characterized by cell walls that contain chitin.

Glomeromycetes

________ are symbionts that form intracellular associations called mycorrhizae with the roots of plants.

fungus

A(n) ________ may be a unicellular yeast or a filamentous, multicellular mold.

Hyphae

________ in the basidiomycetes have septa.

Plasmogamy

________ occurs as the gametangia fuse.

Meiosis

________ produces four genetically different haploid (n) nuclei.

Fungi

________ are eukaryotic heterotrophs that secrete digestive enzymes onto their food source and then absorb the predigested food.

Glomeromycetes

________ have coenocytic hyphae.

Fungi

________ cause huge economic losses by damaging food and crops.

plasmogamy

Both ________ and karyogamy occur, producing a flagellate zygote.

Fungi

________ are used to make many medications, including penicillin and other antibiotics; they are used in bioremediation and to control pests biologically.

Fungi

________ are also being investigated for the biological control of insects.

Lichens have three main forms

crustose, foliose, and fruticose