chapter 34

Question 1

fungi

Answer 1

an abundant and diverse group of heterotrophic eukaryotic organisms, principally responsible for the decomposition of plant and animal tissue

Question 2

hyphae

Answer 2

in fungi, highly branched filaments that provide a large surface area for absorbing nutrients

Question 3

mycelium

Answer 3

a network of branching hyphae

Question 4

chitin

Answer 4

a modified polysaccharide containing nitrogen that makes up the cell walls of fungi and the hard exoskeletons of arthropods

Question 5

septa

Answer 5

in fungi, a wall that partially divides the cytoplasm into separate cells in hyphae

Question 6

yeasts

Answer 6

a single-celled fungus found in moist, nutrient-rich environments

Question 7

mycorrhizae

Answer 7

symbioses between roots and fungi that enhance nutrient uptake

Question 8

ectomycorrhizal fungi

Answer 8

one of the two main types of mycorrhizae; ectomycorrhizae produce a thick sheath of fungal cells that surround, but do not penetrate, root cells

Question 9

endomycorrhizal fungi

Answer 9

one of the two main types of mycorrhizae; endomycorrhizal hyphae penetrate into root cells, where they produce highly branched structures that provide a large surface area for nutrient exchange

Question 10

endophytes

Answer 10

a fungus that lives within leaves and that may help that host plant by producing chemical that deter pathogens and herbivores

Question 11

fruiting bodies

Answer 11

a multicellular structure in some fungi that facilitates the dispersal of sexually produced spores

Question 12

heterokaryotic

Answer 12

describes a stage in the life cycle of some fungi, in which plasmogamy is not followed immediately by karyogamy and the cells have unfused haploid nuclei from both parents

Question 13

dikaryotic (n + n)

Answer 13

having two haploid nuclei, one from each parent, in each cell

Question 14

mating types

Answer 14

genetically distinct forms of individuals of fungus species that, by enabling fertilization only between different types, prevent self-fertilization and promote out-crossing

Question 15

chytrids

Answer 15

a single-celled aquatic fungus with chitin walls that attaches to decomposing organic matter

Question 16

zygomycetes

Answer 16

fungi groups that produce hyphae undivided by septa and do not form multicellular fruiting bodies; they make up less than 1% of known fungal diversity

Question 17

glomeromycetes

Answer 17

a monophyletic fungal group of apparently low diversity but tremendous ecological importance that occurs in association with plant roots

Question 18

ascomycetes

Answer 18

a monophyletic fungal subgroup of the Dikarya, making up 64% of fungal species, in which nuclear fusion and meiosis take place in an elongated saclike cells called an ascus

Question 19

basidiomycetes

Answer 19

a monophyletic fungal subgroup of the Dikarya, including smuts, rusts, and mushrooms, in which nuclear fusion and meiosis take place in a club-shaped cell called a basidium