Trends of gametophyte in evolution of plants
Explain the trends of gametophyte in evolution of the plants?
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A tendency of gametophyte evolution within the plants has been towards the formation of the gametes which are independent from the water. In the bryophytes and in the pteridophytes the fecundation is totally dependent upon the water. Within the phanerogamic plants such dependency is not there.
Another tendency includes the reduction in size and duration of the gametophyte. In bryophytes, the gametophyte is the lasting stage. In pteridophytes, gymnosperms and angiosperms became the temporary stage and its relative size was successively decreased.
A third evolutionary trend is related to the interdependency between the gametophytes and sporophytes. In bryophytes, the sporophyte is solely dependent upon the gametophyte in order to survive. In the remaining plants, the sporophyte refers to the independent stage and the once autotrophic gametophyte in the bryophytes and pteridophytes became dependent on the sporophyte in phanerogamic plants.
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