General plant evolution Flashcards
Explain the difference between derived and ancestral traits
ancestral: traits shared amongst common ancestor and descendents
derived: traits shared amongst descendents but not common ancestor
Describe monophyletic, paraphyletic and polyphyletic groups
mono - MCA + all descendents
para - MCA + some descendents
poly - groupings that do not share a MCA
What traits do the freshwater algae Chara share with land plants?
- starch storage
- cellulose
- sporopollenin
- chloroplasts
- similar life cycles
- cytokinesis
What is a phragmoplast?
a collection of microtubules and vesicles that create the cell wall/plate that divides daughter cells during mitosis
What are the life stages for Chara?
mature body (n) –> oogonium/antheridium (n) –> egg/sperm (n) –> zygote (2n) –> immature body (n)
What are the four evolutionary themes of plants?
vasculature, alternation of gen., seeds, flowers
What are the steps for plant life cycles (mitosis/meiosis)?
meiosis in sporophytes = haploid spores (n)
spores undergo mitosis to form gametophyte (n)
mitosis in gametophytes = gametes (n)
gametes fertilize and fuse to form diploid zygotes (2n)
zygotes undergo mitosis to form sporophytes (2n)
What is the reproductive structure of sporophytes?
sporangium (produces spores)
What are the reproductive structure of gametophytes?
archegonium (produces eggs) and antheridium (produces sperm)
What common traits are shared in land plants?
- alternation of gen.
- creation of spores in sporangium
- creation of gametes in gametangia (archegonium/antheridium)
- are embryophytes (embryo is retained to and dependent on parent)
- tissues are formed through division + differentiation of meristem cells
In what stages are gametes and spores produced?
gametes = mitosis
spores = meiosis
