Lecture 23- Gymnosperms Flashcards
do gymnosperms have fruits or flowers?
no
what are examples of gymnosperms?
cones (conifers)
where are seeds on cones?
surface of scales
what is a seed?
sporophyte embryo
has food supply packaged in a protective coat
how long is the process of an ovule to a seed in a gymnosperm?
1 to 3 years
what does the megaspore (n) on an ovule turn into?
female gametophyte then the seed
what are the 3 key features to the gymnosperm life cycle?
dominance of the sporophyte generation
development of seeds are from fertilized ovules
pollen transfers the sperm to ovules
what is the process of the pine lifecycle?
fertilization
embryo (2n)
mature sporophyte/ pine tree (2n)
for females: ovulate cone from pine tree produces megasporocyte (2n)
for males: pollen cone (2n) from pine tree produces microsporangia (2n), meiosis, pollen grains (n) goes to the megasporocyte to germinate
the germinated megasporangium undergoes meiosis
what are 4 phyla in the gymnosperms?
cycadophyta
ginkgophyta
gnetophyta
coniferophyta
what is unique about the phylum cycadophyta and ginkgophyta?
have flagellated sperm (unlike other seed plants)
what is unique about the phylum gnetophyta?
species in the phyla vary in appearance
some are tropical and others live in deserts
what is unique about phylum coniferophyta?
grow tall
largest gymnosperm phyla
are gymnosperms dicots/ eudicots or monocots?
dicots
what is the difference between dicots and monocots?
dicots have two cotyledons
monocots have one cotyledon
do dicots have an endosperm?
no
