Plant Diversity Pt.2 Flashcards
Chapter 30
when did seed plants originate
360 million years ago
seed
embryo and nutrients surrounded by protective coat
when were plants domesticated?
8,000 years ago
what factors are common to seed plants
- reduced gametophytes
- heterospory
- ovules
- pollen
the ancestors of seed plants were likely ____sporous
homosporous, while seed plants are heterosporous
megasporangia
give rise to female gametophytes
microsporangia
give rise to male gametophytes
what does an ovule consist of?
megasporangium, megaspore, 1+ protective integuments
how many integuments do gymnosperm megaspores have?
one
how many integuments do angiosperm megaspores have?
two
what evol. advantages to seeds provide over spores?
- remain dormant until favorable conditions
- supply stored food
- transported long distances
progymnosperms
late Denovian plants that began to acquire adaptations that characterized seed plants
when did angiosperms begin to replace gymnosperms
near Mesozoic
angiosperms today…?
dominate terrestrial ecosystems
conifers
cone-bearing gymnosperms that dominate in northern latitudes