Lecture 19: Non-Vascular and Vascular Seedless Plants (Midterm III) Flashcards
Three phyla of nonvascular plants
- liverworts, phylum hepatophyta
- hornworts, phylum anthocerotophyta
- mosses, phylum bryophyta
- mosses are most closely related to vascular plants
In bryophytes, which stage is the dominant stage
gametophyte
How often are sporophytes present in the gametophytic stage and how?
only part of the time; embyronically attached to the gametophyte
how does a spore become a gametophyte
a spore germinates into a gametophyte composed of a protonema and gamete-producing gametophore
____ , not roots anchor ________ to the substrate in the gametophytic stage
rhizoids; gametophytes
what constrains the height of gametophytes?
lack of vascular tissue
mature gametophytes produce what?
flagellated sperm in antheridia; egg in each archegonium
in the gametophytic stage, how do sperm reach and fertilize the egg?
sperm swim through a film of water
In the sporophytic stage, bryophyte sporophytes grow out of ?
they grow out of archegonia
what are the smallest simplest sporophytes of all extant plant groups?
bryophytes
structure of a sporophyte
a foot, seta(stalk), and a sporangium/capsule, which discharges spores through a peristome
hornwort and moss sporophytes have what for gas exchange that liverworts do not?
stomata
hornwort and moss sporophytes have what for gas exchange that liverworts do not?
stomata
seedless vascular plants evolved which two tissues?
xylem and pholoem
in seedless vascular plants, what did vascular tissues do? (2)
- provide structural support
- allow plants to grow tall
seedless vascular plants live in what type of environment and have what?
have flagellated sperm & restricted to moist environments
the life cycle of seedless vascular plants involves what dominant generation?
dominant sporophytes w/ well-developed roots & leaves
function of xylem (vascular tissue)
- conducts most of the water & minerals & includes dead cells called tracheids
- strengthened by **lignin –> structure **
- allowed increased height
function of phloem (vascular tissue)
phloem consists of living cells & distributes sugars, amino acids, and other organic products
explain roots and their evolution
1.roots are organs that anchor vascular plants
2. they enable vascular plants to absorb water & nutrients from the soil
3. roots may have evolved from subterranean stems
- bryophytes don’t have roots, they have rhizoids w/no tissues
explain leaves and the different types of leaves
- leaves are organs that **increase the surface area **of vascular plants –> more solar energy used for photosynthesis
- two types
a. microphylls - single vein
b. **megaphylls **- highly branched vascular system
What are the two phyla of seedless vascular plants?
- Lycophyta includes club mosses, spike mosses and quillworts
- Monilophyte = Pteridophyta includes ferns, horsetails, and whisk ferns and relatives
Phylum Lycophyta (seedless vasc. plant)
- giant lycophytes thrived in moist swamps for millions of years
- surviving species are small herbaceous plants
- club mosses and spike mosses have vascular tissues and aren’t true mosses
Phylum Monilophyte = Pteridophyta (seedless vasc. plant)
- ferns are the most diverse seedless vascular plants (12,000 species)
- most diverse in tropics; also in temperate forests
- horsetails were diverse during Carboniferous period, now restricted to the genus Equisetum
- Ferns resemble ancestral vascular plants but are closely related to modern ferns
