Overview of Land Plant Evolution
||Describe four shared
derived homologies that link charophyceans and land plants.
||Distinguish among the
kingdoms Plantae, Streptophyta, and Viridiplantae. Note which of
these is used in the textbook.
characteristics that distinguish land plants from charophycean
algae. Explain how these features are adaptive for life on land.
||Define and distinguish
among the stages of the alternation of generations life cycle
||Describe evidence that
suggests that plants arose roughly 475 million years ago.
||List and distinguish among
the three phyla of bryophytes. Briefly describe the characteristics
of each group.
||Distinguish between the
phylum Bryophyta and the bryophytes.
||Explain why bryophyte
rhizoids are not considered roots.
||Explain why most bryophytes
grow close to the ground.
||Diagram the life cycle of a
bryophyte. Label the gametophyte and sporophyte stages and the
locations of gamete production, fertilization, and spore production.
||Describe the ecological and
economic significance of bryophytes.
Origin and Diversity of Vascular Plants
||Describe the five traits
that characterize modern vascular plants. Explain how these
characteristics have contributed to their success on land.
microphylls and megaphylls.
||Distinguish between the
homosporous and heterosporous condition.
||Explain why seedless
vascular plants are most commonly found in damp habitats.
||Name the two clades of
living seedless vascular plants.
||Explain how vascular plants
differ from bryophytes.
||Distinguish between giant
and small lycophytes.
||Explain why whisk ferns are
no longer considered to be “living fossils.”
||Describe the production and
dispersal of fern spores.
||Many students have
difficulty in understanding the significance of derived characters
that are shared between two extant groups. Just as many members of
the general public have the mistaken notion that humans evolved from
chimpanzees, some students will think that charophyceans are in some
sense ancestral to plants or that charophyceans are identical to the
last common ancestor that plants and charophyceans shared.
||It is important to make
sure that your students understand alternation of generations in
bryophytes and seedless vascular plants. Plant life cycles are
challenging for all students. Without a good understanding of the
life cycles of plants with recognizable gametophytes and sporophytes,
students will have great difficulty with gymnosperm and angiosperm
||Students tend to think of
derived traits as “advanced.” Be careful to avoid this term.
Point out that organisms have a combination of primitive and derived
traits, and that all living organisms have an equally long
evolutionary history, dating back to the origin of life on Earth.
||Many students are not very
familiar with or knowledgeable about plants. Some of the terminology
of plant life cycles can be confusing to such students. Clarify for
students the meaning of these pairs of terms:
a. homosporous and heterosporous
b. bryophyte and phylum Bryophyta
c. rhizoid and root