298 ■ CHAPTER 16 Plants, Fungi, and Protists
REVIEWING THE SCIENCE
● (^) There are at least three
main groups of fungi—
zygomycetes, ascomycetes,
and basidiomycetes—and
each group is characterized
by distinctive reproductive
structures (fruiting bodies).
● (^) Most plant roots in natural
habitats form close
associations with beneficial
fungi, called mycorrhizal
fungi. A lichen is a mutually
beneficial association
between a fungus and a
photosynthetic microbe,
usually a green alga or a
cyanobacterium.
THE QUESTIONS
The Basics
(^1) Which of the following descriptions is not true of all
eukaryotes?
(a) They are multicellular.
(b) They have cellular organelles.
(c) They have a larger cell size than prokaryotes have.
(d) They have a true nucleus.
(e) All of the above are characteristics of all eukaryotes.
(^2) Protists
(a) are the largest prokaryotes.
(b) are all single-celled.
(c) include plants and fungi.
(d) are an unnatural grouping, placed together for convenience.
(e) are all photosynthetic.
(^3) Fungi
(a) reproduce only sexually.
(b) reproduce only asexually.
(c) may have multiple mating types within a single species.
(d) are more closely related to plants than to animals.
(e) are more closely related to protists than to animals.
(^4) Which of these evolutionary innovations enabled larger
cell size?
(a) autotrophic mode of nutrition
(b) multicellularity
(c) sexual reproduction
(d) subcellular compartmentalization
(e) all of the above
(^5) Select the correct terms:
Green algae belong in the kingdom (Plantae / Protista). They are
(aquatic / terrestrial) and are (autotrophs / heterotrophs).
● (^) The domain Eukarya is
traditionally divided into four
major kingdoms: Protista,
Plantae, Fungi, and Animalia.
Eukaryotes possess a true
nucleus; they have complex
subcellular compartments,
which enable larger cell
size. Sexual reproduction
and multicellularity are key
evolutionary innovations of
the Eukarya.
● (^) Kingdom Protista, the
protists, lumps together
many evolutionarily distinct
lineages under one highly
diverse grouping. Most
protists are single-celled and
microscopic.
● (^) Protists are traditionally
divided into two categories:
protozoans, which are
nonphotosynthetic and
motile; and algae, which are
photosynthetic and may or
may not be motile.
● (^) Plants are descended from
green algae and have evolved
numerous evolutionary
innovations to adapt to
life on land. All plants
photosynthesize and use
cellulose to strengthen their
cell walls.
● (^) The first plants, the ancestors
of present-day bryophytes
(liverworts and mosses), had
relatively thin bodies and
absorbed water through a
wicking action.
● (^) Ferns were the earliest plant
group to grow larger and taller
than the bryophytes. This
extended growth required
both cellulose and lignin to
provide structure to plant
bodies, as well as a network
of fluid-transporting tissues
called the vascular system.
● (^) Pollen and seeds first evolved
among the gymnosperms,
the plant group that includes
cycads.
● (^) Angiosperms evolved
flowers, and they enclose
their seeds in the fruit. Many
angiosperms recruit animals
to deliver pollen and also to
disperse their seeds.
● (^) The fungi are distinguished
by their mode of nutrition:
they acquire their nutrients
by absorption, digesting their
food outside of their bodies.
To accomplish this, their
bodies consist of a mycelium
composed of hairlike threads
called hyphae.
● (^) Fungal reproduction may be
sexual or asexual. During
reproduction, a fruiting
body is formed that releases
spores into the environment.
Much as seeds do, these
spores then develop into new
individuals.