lecture 20 seed plants

why were pollen grains an important adaptation for successful reproduction on land?

it eliminated the need for a film of water and can be dispersed greater distances. It gives rise to a pollen tube that discharges 2 sperm into the female gametophyte if a pollen grain germinates

what are the life histories of a pine plant?

it is the sporophyte and makes sporangia in male and female cones. small cones make microspores within pollen grains, the microspore turns into male gametophyte. larger cones have ovules which produce megaspores that turn into female gametophytes

what are the life histories of a flower plant?

they are in the phylum anthophyta and many species are pollinated by animals and some are wind pollinated

which structures are part of the gametophyte generation in pine and flower plants?

the pollen grains (male) and ovules (female)

which structures are haploid in gymnosperms?

pollen grains, mega/microspores, egg cell, female gametophyte

which structures are diploid in gymnosperms?

sporophyte, ovule, zygote, embryo, seed coat

which structures are haploid in angiosperms?

egg nucleus, discharged sperm nuclei, sperm, egg, microspore, male gametophyte

which structures are diploid in angiosperms?

mature flower, zygote, embryo, seed coat, microsporocytes, ovule

sepals

protects flower and keeps it from drying out

petals

attracts pollinators

stamens

produces microspores which makes pollen

carpels

makes megagaspores, female gametophytes and then seeds

filament

holds the anther up

anther

produces and stores pollen grains

stigma

helps to collect pollen

style

guides pollen tube to ovary to facilitate fertilization

ovary

prepares ovules for fertilization, protects developing zygotes, and develops into a fruit

ovule

produces egg cells which creates seeds

how are fruits adapted to disperse seeds?

they are dispersed by wind, water, or animals

how have land plants changed over the source of evolution with respect to their dependence on water?

their dependency has decreased significantly