Angiosperms
Lifecycle
Angiosperms have alternation of generations with the 2n sporophyte as the dominant generation. The anthers produce microspores by meiosis which develope into male gametophytes (= pollen). The ovaries produce megaspores which grow into female gametophytes which then produces an egg.
A pollinator transferrs the pollen to the stigma and a pollen tube grows down into the ovary.Then the sperms travel down the pollen tube. Those sperms then unite with the egg and fertilize into a zygote. This zygote then grows into an embryo with seed coat and a fruit around it. The fruit then waits to be eaten by (i.e.) an animal which spreads the seed and drops it somewhere else. If the conditions are favorable the seed germinates and developes into a new sporophyte.
A pollinator transferrs the pollen to the stigma and a pollen tube grows down into the ovary.Then the sperms travel down the pollen tube. Those sperms then unite with the egg and fertilize into a zygote. This zygote then grows into an embryo with seed coat and a fruit around it. The fruit then waits to be eaten by (i.e.) an animal which spreads the seed and drops it somewhere else. If the conditions are favorable the seed germinates and developes into a new sporophyte.
EXAMPLES
Pineapple Tree
Cherry Tree
Tomato
The Flower
Stamen Male gametophyte consisting of anther amd filament
Filament Long, thin stalk supporting the anther
Anther Oval sac where meiosis takes place, producing haploid male gametophytes (pollen grains)
Carpel Innermost part of a flower that produces the female gametophytes
Stigma On top of the Stuyle ( sticky portion); there pollen grains frequently land
Style Diameter of the carpel narrows into a stalk; tube for pollen into ovary
Ovary Contains one or more ovules where female gametophytes are produced
Ovules Produces female gametophytes
Petal Attract insects& other pollinators to flower; don't produce reproductive cells
Sepal Enclose the bud before it opens, protects the flower while it is developing
Filament Long, thin stalk supporting the anther
Anther Oval sac where meiosis takes place, producing haploid male gametophytes (pollen grains)
Carpel Innermost part of a flower that produces the female gametophytes
Stigma On top of the Stuyle ( sticky portion); there pollen grains frequently land
Style Diameter of the carpel narrows into a stalk; tube for pollen into ovary
Ovary Contains one or more ovules where female gametophytes are produced
Ovules Produces female gametophytes
Petal Attract insects& other pollinators to flower; don't produce reproductive cells
Sepal Enclose the bud before it opens, protects the flower while it is developing
Parallel Evolution in Plants
Many plants can not survive on its own and evolved to be dependent on a certain function or event. The Angiosperms, for example, depend on insects or other pollinators to fly from one flower to another and to pollinate the plant. Without those pollinators, there won't be any flowering plants and without flowering plants there won't be any pollinators. They therefore evolved together.