Chapter 29 Plant Diversity
Questions
1. Distinguish between the four main groups of land plants. The four main groups are green
algae, bryophytes such as liverworts, mosses and hornworts, pteridophytes and seed
plants.
2. Describe the four great evolutionary episodes in the history of land plants. Ordovician,
Early Devonian, Late Devonian and Cretaceous.
3. Describe four shared derived homologies that link charophyceans and land plants. traits
that they have together are Rosette shaped cellulose synthesizing complexes, Peroxisome
enzymes, Structure of flagellated sperm, Formation of a phragmoplast
4. Describe eight characteristics that distinguish land plants from charophycean algae.
Explain how these features facilitate life on land. Charophyte algae inhabit shallow
waters around the edges of ponds and lakes, where they are subject to drying. In
charophytes there is a layer called sporopollenin.
5. Define and distinguish between the stages of the alternation of generations reproductive
cycle. Compare the life cycle of humans with alternation of generations. The stages of
alternation of generation include meiosis and mitosis. Gametophytes (n) and Sporophytes
(2n) occur in this diagram. The alternation of generations repeats itself going over and
over again. Feeding one another.
6. Describe the evidence for a phylogenetic connection between land plants and green algae.
The accumulation of such traits by at least one population of charophyte ancestors
probably enabled their descendants.
7. Describe the fossil record of the early land plants 550 to 425 million years ago. 475
million years old fossil spores resemble those of plants, but they have differences such as;
fossil spores are fused together in groups of two or four. Same year ago, spores of this
age were embedded in plant cuticle material that is similar to spore bearing tissue in
living plants.
8. Describe a likely hypothesis for the origin of alternation of generations in plants. One
produces the other and so forth going over and over again. For example, a pen makes a
pencil and the pencil makes the pen and on and on and on.
9. Explain how adaptations of charophycean algae to shallow water preadapted plants for
life on land. Sporopollenin prevents exposed zygotes from drying out. The accumulation
of such traits by at least one population of first land plants.
10. Distinguish between the kingdoms Plantae, Streptophyta, and Viridiplantae. Note which
of these is used in the textbook. Plantae consists of land plants and embryophytes,
Strpotophyta consists of charophyta and embryophytes, Viridiplantae consists of
charophyta, embryophytes and chlorophyta.
11. List and distinguish between the three phyla of bryophytes. Briefly describe the members
of each group, note their common names, and indicate which phylum represented the
earliest plants. The three phyla of bryophytes are Liverworts ( Hepatophyta),
Hornworts( Anthocerophyta) and Mosses( Bryophyta). The Liverworts are described as
thalloids, they look like miniature tree and are very leafy. Hornworts are lacking of seta
and consist of a sporangium. Mosses have sporophytes that typically are elongated and
visible to the naked eye.
12. Describe the structure of the sporophyte and gametophyte stages of bryophytes grow
close to the ground. Bryophytes have the smallest sporophytes of all extent groups,
sporophytes consists of a foot, a set a sporangium, hornwort and moss sporophytes are
larger than those of liverworts. Gametophyte consists of protonema, apical meristem that
generates a gamete producing structure called gametophore. The form ground hugging
carpets because their body parts are thin to support a tall plant.
13. Describe the stem like and leaf like structures that occur in mosses. For mosses, they
have a mass of green called protonema which enhances absorption of water and mineral.
A gametophore and a protonema make up the body of a moss.
14. Diagram the life cycle of a bryophyte. Label the gametophyte and sporophyte and the
locations of gamete production, fertilization, and spore production. You can’t really draw
it, so yeah.
15. Describe the ecological and economic benefits of bryophytes. Wind allows the spores to
travel all around the world. Bryophytes can survive dry and cold places because they do
not rely on water as much as we would. One moss called peat moss is important because
this decay organic material allows dead people to rot for thousands of years and has been
used as a fuel source.
16. List and distinguish between the groups of modern vascular plants. Explain how they are
different from bryophytes. Modern vascular plants have tracheids and because of that
they have lignins that strengthen the cell walls allowing them to grow tall. Tall plants are
able to shade the little plants. Also, as it strengthened on the way up, it also strengthened
on the way down with its roots.
17. Describe the adaptations of vascular plants, including modifications of the life cycle and
modifications of the sporophyte, that have contributed to their success on land. The
vascular plants were able to shade the little plants. The sporophylls modified leaves that
bear sporangia.
18. Compare the structure of pteridophytes and lycophytes. Pteridophytes have megaphylls,
but the lycophytes do not and lycophytes can branch at various points along the length of
an existing root. For Pterophytes, the sporophytes typically have horizontal stems that
give rise to large leaves called fronds.
19. Distinguish between homosporous and heterosporous conditions. Homosporous have one
type of sporangium that produces one type of spore, but heterosporous has two types of
sporangia and produces two types of spore.
20. Explain why seedless vascular plants are most commonly found in damp habitats. Tree
lycophytes thrived for millions of years in moist swamps. The intake of water was
possible when plants had roots.
21. Describe the structure and habitats of giant and small lycophytes. The small lycophytes
consists of small herbaceous plants and the other is woody treelike plants with diameter
of more than 2 meter.
22. Compare the typical structure of ferns, sphenophytes, and psilophytes. Convincing
evidence that all three groups form a clade. They are classified as the phylum Pterophyta.
23. Describe the production and dispersal of fern spores. Numbering more than 12000
species. Most diverse in the tropics, many fern thrive in temperate and some species are
even adapted to arid habitats. The fern spores disperse around the world because of the
wind. Production usually happens in wetland because of the need of water.
24. Describe the major life cycle differences between mosses and ferns. In mosses there are
two ways for haploid; on the other hand, fern has only one way for haploid. The
sporangium is different in size because the capsule is on top of the female sporophyte, on
the other hand, the mature sporophyte for sporangium is smaller than the life cycle of the
moss.
25. Explain how coal is formed and note during which geologic period the most extensive
coal beds were produced. Coal is made from peat. Heat and pressured converted it to
coal and Carboniferous coal deposits are the most extensive to form.