LearnSmart: Chapter 32

Which describes mycelium?

A mass of connected hyphae

Chytridiomycosis is an example of which of the following?

A parasitic fungi-animal symbiosis

What are mycorrhizae?

Associations between the hyphae of certain fungi and the roots of plants

Where do zygomycete sporangia form during asexual reproduction?

At the tips of sporangiophores

The dikaryon stage occurs primarily in which of the following fungi?

Basidiomycetes and ascomycetes

How do fungi reproduce?

Both sexually and asexually

True or false: All hyphae consist of long chains of cell joined end-to-end.

False

Order the following process in the life cycle of a zygomycete as they occur, starting with the fusion of gametangia at the top.

Fertilization, karyogamy, and meiosis.

Select the feature that distinguishes the chytridiomycota and relatives from the other groups of fungi.

Flagellated spores

What are ascocarps?

Fruiting bodies of ascomycetes

Why is treating fungal diseases in animals particularly difficult?

Fungi are phylogenetically related to animals

A heterokaryotic cell contains two of which of the following structures?

Genetically distinct types of nuclei

Put the steps involved in sexual reproduction in ascomycetes in the proper order. Start with the mating of hyphae at the top.

Hyphae mate, a dikaryotic mycelium produces an ascocarp, nuclei in an ascus fuse by karyogamy, meiosis occurs, and ascospores are released.

Which of the following statements correctly describes asexual reproduction in ascomycetes?

Hyphae produce conidia, which grow into genetically identical hyphae.

Put the steps of zygomycete sexual reproduction in the right order. Start with the production of multinucleate gametangia at the top.

Hyphae produce multinucleate gametangia, gametangia fuse, karyogamy occurs and the zygosporangium develops, a dark and thick-walled zygospore develops, and meiosis occurs to produce haploid spores.

Describe the fungi in lichens.

It can not grow normally without their photosynthetic partners.

Mitosis in multicellular fungi differs from that of other organisms in which way?

It is not followed by cell division

Select all true statements about corn smut.

It produces an edible product and it is caused by a fungal pathogen.

Select all effects of aflatoxins.

Kidney damage, nerve damage, and cancer,

Which of the following is the name given to the entire mass of connected hyphae that make up the body of a fungus?

Mycelium

Fungi in this phylum are anaerobic and produce zoospores

Neocallimastigomycota

What benefit do mycorrhizal fungi receive from their plant partners?

Organic nutrients

Which member of a mycorrhizal relationship benefits through improved uptake of nutrients?

Plant

What structures in septate hyphae allow material to pass through the hyphae?

Pores

Which of the following is not a fungal group?

Poriferamycota

Which of the following is a characteristic feature of ascomycetes?

Presence of a dikaryon stage

Which of the following is the most important yeast in baking, brewing, and wine making?

Saccharomyces cerevisiae

Fungi have formed mutualistic symbioses with which of the following?

Some animal species, such as ants and ruminants

What are conidia?

Spores produced by asexual reproduction

Select all characteristics of ectomycorrhizae

The fungal component is usually a basidiomycete and most plant hosts are forest trees such as pines, oaks, and birches.

How does nutrient exchange occur in lichens?

The photosynthetic component provides organic food molecules while the fungal component provides water and minerals.

What are you looking at when you see a fungus growing above the ground in forest soil?

The reproductive structures

Which of the following is true regarding decomposer fungi?

They break down organic material into carbon dioxide, which is used by plants and algae

Where do lichens grow?

They can grow in places too extreme for most plants to grow.

Why are dikaryotic mycelia functionally diploid?

They contain two copies of each gene.

Select all true statements about the Glomeromycota.

They do not undergo sexual reproduction and they form arbuscular mycorrhizae.

Which statement about fungal cells is true?

They may have one, two, or more nuclei

Select all true statements about blastoclads

They produce zoospores and they have a haplodiplontic life cycle

Zygomycete sporangia contain which of the following?

Thin-walled asexual spores

What must occur for a fungus to reproduce sexually?

Two haploid hyphae of compatible mating types must fuse.

Match the basidiomycete cell type with the karyotype.

Unfused hyphae are haploid, fused hyphae are dikaryotic, and basidia are dikaryotic then diploid.

What are yeasts?

Unicellular fungi

Which fungal genus includes a plant pathogen?

Ustiliago

Select the four traditional fungal phyla.

Zygomycota, ascomycota, chytridiomycota, and basidiomycota.

Carcinogenic compounds produced by some Aspergillus flavus strains are called ___.

aflatoxins

Fungi are most closely related to

animals

Most vascular plant species enhance water and mineral absorption through ___ mycorrhizae

arbuscular

Chitin is also a major portion of the exoskeleton of ___, a group of animals that includes insects and crustaceans.

arthropods

Ascomycetes produce fruiting bodies called ___.

ascocarps

Ascomycete fungi produce sexual spores called

ascospores

The phylum Ascomycota derives its name from the production of sac called a(n) ___, which carries sexual spores

ascus

The sac that contains sexual spores in ascomycetes is called a(n)

ascus

Hyphae grow in length

at their tips

The main decomposers in the ecosystem are fungi and ___.

bacteria

Hyphae of arbuscular mycorrhizal fungi grow

between the cell wall and plasma membrane of the plant root cell

Ascomycetes often disperse their sexual spores

by throwing them

The cell walls of plants and many protists contain ___ whereas the cell walls of fungi contain ___.

cellulose; chitin

Fungal cell walls are made of

chitin

Centrioles are only produced by

chytrids

Asexual spores that form at the tips of fungal hyphae are called ___.

conidia

Fungi and bacteria are important in most ecosystems because of their role as

decomposers

A fungal mycelium containing two separate nuclei that divide at each cell division is said to be ___.

dikaryotic

A unique aspect of sexual reproduction in fungi compared to other eukaryotes is the occurrence of an intervening ___ stage of varying length after haploid cells fuse.

dikaryotic

The function of a basidiocarp is to

disperse spores

Fungi that live within the leaf and stem tissues of plants without causing disease, are known as ___.

endophytic

Saccharomyces cerevisiae was the first

eukaryote to be sequenced

Yeasts are important commercially because of their ability to

ferment carbohydrates

Arbuscular mycorrhizae are composed of plant roots and

glomeromycete fungi

A hypha that has two or more genetically identical nuclei is said to be ___.

homokaryotic

A mycelium is composed of filaments called ___.

hyphae

The two nuclei of dikaryotic fungal cell function

independently from each other

The fusion of the nuclei of two gametes is called

karyogamy

During sexual reproduction, a hyphal branch from one mycelium fuses with a hyphal branch of a different mycelium of the same species with a compatible

mating type

In zygomycetes, asexual reproduction occurs

more frequently than sexual reproduction

A monokaryotic hypha has

one haploid nucleus

An organism that gains resources from its host (thereby having a negative effect) but does not cause disease (except in some extreme cases) is called a(n) ___.

parasite

In a mycorrhizal relationship, the ___ produces organic nutrients for use by the ___.

plant; fungus

The basidiomycete mycelium composed of monokaryotic hyphae is called the ___ mycelium, while that containing dikaryotic hyphae is called the ___ mycelium.

primary; secondary.

Small cross walls between individual fungal cells of ascomycete and basidiomycete hyphae are known as ___.

septa

Basidiomycetes are fungi with

septate hyphae and club-shaped fruiting bodies

An important role of the ascomycete fungus Saccharomyces cerevisiae is that is

serves as a model organism

During asexual reproduction in zygomycetes, sporangia are produced on the tips of stalks called ___.

sporangiophores

Fungal reproductive cells are called ___.

spores

Since fungi are heterotrophs, they are incapable of

synthesizing essential organic molecules

The two-hybrid system that is used to study protein interactions uses

yeast

Fusion of nuclei within the zygosproangium of a zygomycete results in the production of a(n) ___.

zygospore