BIO
What is the oldest vascuar tissue and from how many MYA?
Cooksonia, 432 MYA
What signified the change from bryophyte lifestyle? Or what was different about the new plant appearance?
The sporophytes werent nutritionally dependant on gametophytes like how bryophytes were. An indepemdant sporophyte is one of the features of vascular plants
Characteristics of extant vascular plants
1) have vascular tissue with lignin
2)complex muticellular roots and leaves (leaves can either me mirophylls or megaphylls - size of vascular system/tissue)
3) the SPOROPHYTE is dominant in this life cycle as they are more complex, bigger, more persistant and arent continuously nutritionally dependant on gametophyte
4)have sporophylls (modified leaves on sporophyte that bear sporangia)
5) variation in spore sizes
homosprous and heterosporous species
this is a characteristic of extant vascular plant. the homo means there is no variation in size of spore and that spore becomes gametophyte that makes both eggs and sperm. Hetero means two sizes of spores. the small ones bacomes a male gametophyte and larger one becomes female
what are the two major extant lineages of seedless vascular plants and what kind of group are they?
Phyum Lycophyte (1200 spp)
Phylum Monilophyta (12000spp)
- monophyletic group
characteristics of seedless vascular plants
1) gametophytes are tiny, and independant right at the soil surface
2)flagellated sperm cells that must swim in water to reach eggs.
Phylum Lycophyta
all their members are microphyllous and can be hetero or homosporous (only small lycophytes exist now cuz the big ones died in cold climate)
example of member of phylum lycophyta
club moss
3 extant groups of phylum moniphyta
whisk ferns ("living fossils" because no roots or leaves)
horsetails (Equisetum, have reduced microphylls)
true ferns (most successful)(megaphylls) (most= homosporous)(most produce clusters of sporangia )