gymnosperms Flashcards
what evolutionary adaptations allowed plants to live and diversify after the water dried out in the carboniferous period?
seeds
what do seeds do?
protect the embryo with stored food and a protective outer coat
gymnosperms are plants that have
seeds
in seed plants, the the sporophyte or gametophyte dominant?
sporophyte
what is the gametophyte dependent on in seed plants?
the sporophyte
in the evolution of pollen and seeds, what does plants being gametophyte dependent, the pollen, ovule, and seeds all have in common as an evolutionary gain?
protection
what is the loss of the gametophyte being dependent on the sporophyte?
more stress on the sporophyte
what is pollen? what is it protected by?
a male gametophyte protected by a pollen grain
what is the evolutionary loss of pollen?
a mechanism is needed to carry the pollen
what is the ovule? what is it protected by?
female gametophyte protected by sporophyte
what is the evolutionary loss of the ovule?
sporophyte needs extra care
what do seeds contain?
the next-generation sporophyte
what is the evolutionary loss of seeds?
great energy cost to plant
what is heterospory?
two types of sporangia: megasporangia and microsporangia
in the gymnosperm life cycle, how does pollination and seed dispersal occur?
the wind!
in female gametophytes, what three things create the ovule?
integuments, megasporangium and megaspores
in the ovule, what haploid is produced within what diploid?
megaspore (n); megasporangium (2n)
the megaspore undergoes what process to become to female gametophyte?
mitosis
where are male gametophytes formed?
within the pollen grain
in the pollen grain, what haploid is produced within what diploid to form the male gametophyte?
microspore (n); microsporangium (2n)
the microspore undergoes what process to become the male gametophyte?
mitosis
do the sperm need to swim? how does it get to the female gametophyte?
no! sperm swims through the pollen tube (lazy ass sperm)
what are pollen grains coated with?
sporopollenin
sperm delivers pollen directly to the?
egg (ovule)
how is the pollen tube formed?
by pollen grains
what happens to the extra sperm cells?
they become the food source for the female gametophyte
in pollination, pollen is transferred to what part of the seed?
the female gametophyte that contains the ovule
the male gametophyte is protected in the?
pollen grain
a seed is an embryo in __________ tissues that is wrapped in a parent __________
gametophyte; sporophyte
how is the size of the seed determined?
the amount of gametophyte derived food
seeds are what kind of stage?
the dispersal stage
what is the contrast between seeded plant and non-seeded plant stages?
seeds are in the dispersal stage and spores are in the travelling stage