![]() ![]() However, it is possible for the protonema to become dominant over the leafy growth in a minority of moss species. These plants render the protonemata as transient, which is what happens in most species, as they become the dominant growth form. ![]() ![]() The stems may develop leaves that form into leafy-stemmed plants. It forms in the very early stage of the moss life cycle, and paves the way for single or multiple stems to grow from it. A protonema is a chain of cells, which can resemble an algal colony or a fern prothallus. Moss spores will develop a protonema when they germinate. Although moss and other land plants share this biological model of alternating generations, the way the model works in moss is the complete opposite of the majority of other land plants. It provides the sporophyte with water and nutrients. The sporophyte relies on the gametophyte to survive, making the latter the dominant generation. Once fertilised, the egg will develop into a sporophyte, which then produces spores. Sperm cells travel from one gametophyte to another through a thin film of water to fertilise an egg. The gametophyte has half the genetic material as the second generation, and forms when the sporophyte releases spores which start to divide. What are alternating generations? Simply put, mosses have two alternating generations: Mosses may be different to other land plants in that they are rootless and reproduce through spores rather than seeds, they do share a similar life cycle in that they have an alternation of generations. ![]()
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