chapter 27 learning curve
Which of the nonvascular plant clades has the highest number of extant species?
Bryophyta (mosses)
Which is the correct order of appearance of features during plant evolution?
Endosymbiotic chloroplasts, retention of egg on parental tissue, protected embryo, stomata, tracheids, megaphylls, heterospory
Which statement about plant life cycles is true?
Homosporous plants evolved before heterosporous plants.
What effect does having a basal region of cell division have on sporophyte function in hornworts?
It allows spores to be continually made and released as long as the sporophytes live
true roots are a synapomorphy of which of the following groups of plants?
Lycophytes, monilophytes, seed plants
Which set of clades correctly describes the tracheophytes?
Lycopodiophyta, monilophyta, cycadophyta, ginkgophyta, gnetophyta, coniferophyta, and angiosperms
Coleochaetophytes have all of the following synapomorphies in common with stoneworts except
apical growth
Unlike the other groups of nonvascular plants, the _______ sporophyte has no stalk and is persistently green—a trait shared with vascular plants.
hornwort
Which characteristic of nonvascular plants has restricted their expansion on land to moist areas?
lack of true roots
Hydrocarbons play two roles in algae: an energy reserve and a way to increase bouancy. The latter is important because it maximizes exposure to _______, providing energy for the algae to fix CO2.
light
Microphylls differ from megaphylls in that
microphylls are thought to have evolved from sterile sporangia, whereas megaphylls evolved from modified branches.
Liverworts, hornworts, and mosses are found on all seven continents. Their survival in harsh environments is aided by
mycorrhizae
What is a monilophyte?
seedless vascular plants like horsetails and ferns
Hornworts can be distinguished from the other nonvascular plants by their
single chloroplast per cell and persistently green sporophyte.
Heterospory in a plant life cycle is characterized by two different kinds of
spores that mature into two different kinds of gametophytes
In recent years, atmospheric levels of CO2 have increased and resulted in a global temperature change. With regard to leaf structure, this increase in CO2 could mean less selective pressure for _______, which would ultimately drive selection for a reduction in leaf area.
stomata
Sporophytes and gametophytes differ from each other genetically because
the sporophytes have one set of chromosomes from each parent, while gametophytes have only one set of chromosomes.
Why is liquid water required for sexual reproduction in mosses?
they have sperm with flagella
Liverworts can be distinguished from the other nonvascular plants because they
they lack stomata
The common ancestor of vascular plants had
tracheids
The earliest clades of photosynthetic eukaryotes that led to land plants
were similar to the modern glaucophytes, red algae, and chlorophytes.
The nonvascular plant that could most easily spread and form a larger colony is one with a sporophyte that has a sporangium
with a long stalk and a mechanism to throw its spores