seed plants Flashcards
(44 cards)
types of seed plants
angiosperms and gymnosperms
when do secondary xylem and phloem develop
before progymnosperms
when do seeds develop
before gymnosperms
when does multicellular embryo sac develop
before angiosperm, consists of female gametophyte composed of many cells, causes food source to change
food source for embryo
endosperm
pro gymnosperms
seedless plants with woody growth, leaves are fronds with spores underneath
seed plants gametophyte
dependent on sporophyte (main body), different from independent gametophyte in seedless plants
are spores released into the environment
no, they stay within the flower structure and grow into gametophytes
male gametophyte
pollen
microspore and megaspore main characteristic
heterosprorous
where are megaspores found
ovule
pollen advantage
allows for reproduction without free water
seed function
provide protection and a food reserve for embryonic sporophyte
integument
outside of ovule, develops into seed coat
megasporangium
area inside ovule
micropyle
entry into ovule where sperm germinate into
are sperm usually flagellated in gymnosperm
no, they just move through the pollen tube to produce the embryo, some gymnosperms are flagellated though
where is the gymnosperm seed
on the surface
four gymnosperm groups:
cyads, gingko, gnetophytes, conifers
gymnosperm importance
make up most of the earth’s biomass
cycads -
most primitive seed plants, dioecious, look like shrubs
how were cycads pollenated
by insects, they don’t produce long pollen tubes, have long flagellated sperm, have symbiotic relationships with cyanobacteria
gingko -
living fossil, have dichotomously branched veins, don’t produce woody cones, dioecious, produce flagellated sperm, have large odorous seeds
pollination drops -
feature of wind pollinated plants, landing site to capture pollen, these drops can contain sugars and amino acids as their main components,
angiosperms pollination drop include a wet stigma on the outside of a closed carpel, allows for a sweeter carbohydrate