Chapter 29 – Plant Diversity
Plants are divided into 4 major groups
a. Nonvascular plants (bryophytes)
b. Seedless vascular plants
c. Gymnosperms
d. Angiosperms
The major derived traits (p. 576-577) that split plants from algae (protists) are:
a. Apical meristems (shoots and roots to elongate and increase exposure to environmental resources like light,
CO2, water, nutrients)
b. Alternation of generations (gametophyte (n) and sporophyte (2n) life cycle)
c. Walled spores produced in sporangia
a. Walled spores allow spores to withstand harsh environments
b. Spores can be dispersed through air without harm
c. A sporangium is an organ that produces spores until they are ready to be released
d. Multicellular gametangia – organ that produces gametes
a. Female is the archegonia that holds the eggs
b. Male is the antheridia that produces and releases sperm (not yet a pollen until we get to seed plants)
e. Multicellular dependent embryos
a. The zygote develops under the protection and nourishment of the parental tissue
Non Vascular Plants (common example: moss)
Important traits of moss:
1. Non-vascular – no transport system
2. Life cycle is dominated by gametophytes rather than sporophytes
3. Large surface area to volume to absorb H2O and nutrients
4. Female gametes remain embedded in archegonia to protect and give nutrient to egg
5. Stomata enable CO2/O2 exchange while minimizing H2O loss
6. Dispersal of light weight spores that can withstand harsh environment and through mitosis grow into a
gametophytic structure later.
Seedless Vascular plants (common example: fern)
Vascular plants have a system for transporting water and nutrients
Xylem
a. conducts water and minerals
b. Includes tracheids
1. tube shaped cells that carry water and minerals up from roots
2. tracheids are dead cells so this is basically a water pipe
3. tracheids have lignin in their cell wall to make them strong and allows plant to stand up
Phloem
a. living cells that bring sugars and other organic products down from the leaves
Important traits of ferns:
1. Sporophyte dominates the life cycle of ferns
2. Presence of xylem and phloem
3. True roots and leaves
Which group do I belong to?
Eubacteria
Archaea
Protist
1. _________________Algae
2. _________________Amoba
3. _________________Anthrax
4. _________________E. coli
5. _________________Fern
6. _________________Halobacteria
7. _________________Moss
8. _________________Paramecium
9. _________________Seaweed
10. _________________Streptococcus
Plant