Studied by 4 people
1. Alternation of generations & life cycles in general 2. Division Bryophyta (Mosses) 3. Division Pterophyta (Ferns etc.) 4. Homospory vs. heterospory 5. Division Coniferophyta (Conifers)
In land plants, meiosis produces _
Spores
Spore
Single cell that can divide to produce multicellular organism
Gamete
Single cell that can unite w another gamete to produce a diploid zygote
Embriophytes
10 divisions, 4 major: moss, fern, conifers, angiosperms
Moss
Low growing
Confined to damp areas
Swimming sperm
No true vascular tissue (rudimentary vascular system)
No true leaves
Gametophyte dominant
Homosporous (1 spore size)
Ferns
~400 mya
Vascular tissue
Xylem & phloem
Support & supply
Swimming sperm
Sporophyte dominant
Homosporous or heterosporous
Fern life cycle
Sporophyte grows out of gametophyte and gametophyte goes away
Homospory
1 size of spore from meiosis
Heterospory
2 sizes of spore from meiosis
Megasporiangium
Female
Microsporangium
Male
5 divisions (phyla) seed plants
Cycadophyta
Ginkgophyta
Gnetophyta
Coniferophyta
Anthophyta
Seed
Embryo + nutrition (megagametophyte in conifers) + Seed coat
Seed development
Develops from ovule
Novel structure appearing in seed plants
Site of female meiosis
Contains female gametophyte, sex organs, egg, & embryo
Diploid conifer @early stage
Integument
Megasporangium
Haploid conifer @early stage
Megaspore
Megagametophyte
Pollen
Mature male gametophyte
Conifers
Reproductive organs in cones
Sporophyte dominant
Heterosporous
Microgametophyte = pollen!
Megagametophyte
within ovule
makes egg & then nourishes embryo
Sporocyte
Single cell that undergoes meiosis to make spores
Where is integument
On outside
when does pollination happen
BEFORE female meiosis
Megagametophyte
Makes egg in archegonium
Nourishes embryo
Microgametophyte
Pollen grain (makes sperm)
Phylum coniferophyta (fir, pine)
Seeds & pollen
Cones: separate male & female
Naked seeds: “gymnosperms”
Seed = embryo nourished by mega-gametophyte
Slow reproduction
Note
Flashcard