Gymnosperm Flashcards
What florea constitute Gymnosperms?
seed fern
cycadophyta
gingkophyta
coniferophyta
gnetophyta
What are seed ferns?
extinct trees that look like ferns and produced seeds
Cycad characteristics
dioecious
thick, woody stems with compound leaves
Male vs female cycad
male has a pollen cone
female has ovules that develop into seeds when fertilized
What is the only species in gingkophyta?
gingko biloba
What is unique about gingko?
physically the same as its extinct ancestors
Conifers characteristics
monoecious
What is the conifer pollen grain like?
gametophyte consisting of four cells (mickey mouse)
How does pinus develop
produces seed cone which develops into pollen cone
builds upwards, newer cone found at the top/ end of shoots
Conifer examples
Pines
yew
monkey puzzle
juniper
Genera in Gnetophyte
gnetum, ephedra, welwitschia
How does Gnetophyta differ from other gymnosperms?
- have primitive vessels in wood (gymnosperm generally only have tracheids)
- no archegonia (naked eggs in Gnetum and Welwitschia)
- double fertilization and origin of the endosperm
