Diversity of Plant Life on Land There are many different species of plants on earth all of which are unique The terrestrial ecosystems where each plant is located plays a key role in the development of the plant Plants of all kinds need an adequate source of water specific to that plant For example mosses need to be located in an environment that is more wet than would be needed for a conifer Ferns conifers and angiosperms are all sporophyte dominant and contain a female sex organ called the archaegonium Mosses also have archaegonium The sporophyte on ferns however are dependent on the gametophyte for reproduction purposes The archaegonium is the female sex organ which means that each of these species are diploid during a portion of their life Mosses and ferns are haploid for the majority of their life but do have a diploid stage Conifers are diploid for the majority of their life Conifers and angiosperms are not dependent on the gametophyte stage for reproduction The gametophyte is dependent on the sporophyte The gametophyte is the seed of the angiosperm When the fruit of the angiosperm falls and decays or is eaten the seed is deposited and the gametophyte will begin to grow leading to a new angiosperm Secondary growth also occurs in both conifers and angiosperms The trunk of the plants undergoes cell division throughout their life which create thicker trunks with more rings Pollination in angiosperms always results in double fertilization Double fertilization is specific to angiosperms Each grain of pollen has 2 sperm one merges with an egg cell to form a zygote The other sperm cell merges with a polar nucleus to form a 3n endosperm which provides energy for the zygote In contrast conifers are pollinated by wind or fire They have non motile sperm that are carried in the pollen grains Works cited Harris Haller T 2016 Laboratory Manuel for Biology 112 9th ed Chapter 5 Hayden McNeil Publishing
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