Seedless Vascular Plants Flashcards
which generation is independent in seedless vascular plants?
Both!
- gametophyte is fully independent
- sporophyte is independent at maturity (but relies on gametophyte as a juvenile)
Which generation is dominant ?
- sporophytes are more prominent and longer lived
What are the major changes from bryophytes?
- the development of vascular tissue and the sporophyte is dominant
are they heterosporous or homosporous?
both!
What does heterospory yield for the life cycle?
- mega and microsporophyll bear microsporangia and megasporangia which produce micro/megaspores which become micro and mega gametophytes which yield archegonia and sperm
What does homospory yield for the life cycle?
- homospores give rise to male and female gametophyte
what are microphylls and megaphylls?
microphyll: single vein
Megaphyll: branched veins
Are lycophytes microphyllic or megaphyllic? What about monilophyta?
- all lycophytes are microphyllic
- monilophyta:
- whisk ferns have no true leaves
- psilotopsida: megaphyllic
- equitopsida: microphyllic
where are sporangia stored in each taxa?
- club moss, spike moss, equisetopsida: strobilus
- polypodiopsida: sori
- quill wort: sporangia
- whisk ferns: sporangia
What are the vascular tissues? What do they transport and in what direction?
xylem transports water and minerals up the plant
phloem transports sugars/proteins everywhere
where is the vascular tissue found in ferns?
- the stem, leaves, roots
- can be seen in veins of leaves
do fern gametophytes have vascular tissue?
-nope! Gametophytes do not have vascular tissue
- instead, they have rhizoids which connects them to the ground and a thallus
Describe the sporophyte of a lycopodicease (club moss)
- strobilus, vegetative leaf: microphyllic
Describe the sporophyte of a selaginella: spike moss
- strobilus, small leaves on underside, microphyllic
Describe the sporophyte of a psilotopsida
- whisk fern
- has enations (not true leaves) and dichotomous branching
- vascular trace does not extend into nation
Describe the sporophyte of a polypodiopsida
- true fern
- macrophyllic
- large fronts
Describe the sporophyte of equitopsida (horse tail)?
- strobilus
- vegetative and reproductive leaves
-whorled branching - branches on the vegetative, and leaves on the reproductive strobilus
What are the leaf types?
enation: no true vascular tissue
- micrpohyl: one vascular trace
- megaphyll: branches vascular traces
describe the relationship between microspore, microsporangia, and microsporophyll?
- in heterospores,
microsporophyll are the leafy structures which bear microsporangia, which produce microspores
Describe the cross section of a microphyll and a megaphyll cross section
microphyll: single vascular bundle with no branching
megaphyll: multiple vascular bundles with multiple branching veins
Where are rhizomes and rhizoids found?
- rhizomes are found in sporophytes, stems (they have vascular tissue)
- rhizoids are found in gametophytes, act as roots (no vascular tissue)
define endoscopic
- gametophyte develops within the spore wall
- associated with heterospory
define exposporic
- gametophyte develops outside the spore wall
- associated with homospory
Define homosporous
one type of spore is produced, which forms a bisexual gametophyte
Define heterosporous
- two types of spores: microspores and megaspores
What is the strobilus? What is it made of ?
- strobilus is a reproductive cone shaped structure
- made up of sporophylls
In homospores, what are the reproductive and vegetative leaves?
- vegetative: microphylls
- reproductive: sporophylls (arms that surround the sporangium)
in heterospores, what are the reproductive and vegetative leaves?
- leaf name indicates what it is holding:
reproductive leaves: micro and mega sporophylls surround the micro and megasporangia
what are the conditions required for dispersal and germination?
- dispersal: wet, windy
- germination: humid/covered, moist, good temperature
What is the annulus?
a ‘catapult’ of spores:
What is the sori?
- clusters of sporangia on underside of fern front
What is the indusium?
- thin protective covering over sori to regulate spore dispersal
What are three terms related to fern spore dispersal?
- indusium, sori, annulum
Describe the spores of whisk ferns
- spores are housed on the stem in sets of 3 sporangium (capsules, sporangia, spores)
What does the sorus refer to?
- the indusium and the sporangia
Where does fertilization occur ?
- in the archegonia
Why are fern gametophytes bisexual?
because they’re homosporous!
what kind of spores are found in fern gametophytes
homospores
what are the three extinct plants that dominated during the Devonian period ?
- rhyniophyta, trimeropytophyta, and zosterophyllophyta
Where is the casparian strip?
- the casparian strip is within the endodermis, which is the layer that separates the cortex and the vascular tissue
- the casparian strip regulates exchange of ions, nutrients, and water from the vascular tissue
are the gametophytes dependant or independent in quillworts?
- dependant: because they are heterosporous, the gametophyte develops endosporically which means that they depend on the sporophyte for nutrients
BUT
if they’re homosporous they develop outside the spore, so they are independent
what is the protective covering of the strobilus called?
sporangiophore
