Seed Plants (Gymnosperms) Flashcards
Derived traits
-two kinds sporangia and two kinds spores
-reduced gametophytes (dependent)
-pollen
-ovules
-seeds
Microsporangia
male gametophytes (sperm)
megasporangia
female gametophytes (egg)
Pollen advantages
-protected from environmental stress
-no water for fertilization
-diverse structure fits all pollination methods
Parts of an ovule
-integument
-megaspore
-megasporangium
-micropyle
pollination
pollen to ovule
Fertilization
fusion sperm and egg
Parts of a seed
-embryo
-food supply
-protective seed coat
Parts of a seed
-embryo
-food supply
-protective seed coat
Advantages of seeds as dispersal stages
-dispersed long distances
-remain dormant
-contain food supply for post-growth germination
Gymnosperms
cycado
ginkgo
gneto
conifero
cycado
large cones
dino times
seperate male female parts
ginkgo
only 1 lineage left
fan shaped leaves
sep male female parts
conifero
needle leaves (thick cuticle and stromata)
abundant
thrive in harsh environment
photosythesize as soon as favorable
conical shape heat retention
Life cycle
-ovulate cone pollinated by staminate cone via wind
-pollen tube grows into ovule, sperm swims down and fertilizes
-zygote matures to seed in 6 months
-female gametophyte tissues provide nutrients to embryo
-seed dispersal, scales ovulate cone seperate to wings
