Ciclo Reprodutivo dos Musgos Briófitas

you you forests are dominated by large plants and crowd one another than their competition for light but far below on the forest floor are the group of tiny plants known as the mosses with over 10,000 species these plants thrive in many habitats these most plants form gametes and are therefore gametophyte Mosca me two fights are haploid containing only one set of chromosomes they're small and compact form enables a stems to stay upright while rhizoids anchor them to the soil moisture easily accumulates around the density spaced stems this often leaves a film of water on the leaves and on the stem tip he'll i growths called prophesies help to hold the water around the stem tips some stem tips are male and contain reproductive structures called antheridia these are complex organs consisting of many cells each is supported by a stored the upper portion consists of an outer protective jacket that surrounds a group of sperm cells at the tip of a female gland there are numerous reproductive structures known as archegonia the top of each consists of a slender neck the middle region contains a chamber called the Venter the base of the archegonium is attached to the moss stem by a stalk an egg cell is formed inside the Venter inside the neck the breakdown of cells forms a central canal containing sperm attractant a range sharp provides the ideal conditions for sperm release and their transfer to a female plant droplets of rain water collect at the tips of the Moss stems inside the drop of water the tip of the male stem the antheridia are open this releases cells containing sperm which float up to the surface rain drops flashed some of this water out of the male plant some splash drops contain sperm cells and fall onto the tip of a female stem the sperm now escaped from their surrounding membrane and use their flagella to move about in search of an egg the archegonium now opens and releases a sperm attractant the spurns win towards the source of the attractant and into the opening once inside they are guided down to the egg the first bomb to arrive enters the Excel fertilization is completed with a sperm and egg nuclei fuse creating a diploid zygote after fertilization many changes take place on the female stem tip at first the zygote remains within the Venter where it forms an embryo however one end of the embryo soon grows out of the Venter and into the female stem this allows it to obtain water and nutrients from the female plant the other end of the embryo grows upward the Venter expands to accommodate this growth but eventually at the split in half the embryo now forms a very long stalk or sita that lifts the top half of the vendor up into the air this results in a small diploid plant the sporophyte attached to the tip of the female stem these female stems have all been fertilized and supports sporophytes above them the tip of each is covered by the torn Venter orca lip Terra this soon falls away exposing a capsule or sporangium the capsule contains fertile tissue consisting of Sparra sites inside the nucleus of each Sparra site there are two sets of chromosomes the nucleus divides by the process of meiosis forming four haploid nuclei thin walls now form around each nucleus resulting in a cluster of four cells known as the tetrad a deposit of spara pollen produces cells with thick resistant walls called spores as the spores are forming the capsule dries out in hardens soon the lived or operculum falls away revealing a ring of fine teeth called the Paris dome these rather than opening on the capsule as they dry out they bend backwards allowing the spores to escape a light breeze is all it takes to carry the spores away from the parent plant spores carried by the wind may land on an exposed surface after rain the spore cell absorbs water and germinates but instead of drying into a new Moss plant it forms a branch filamentous Pro taneema however after a period of growth some of the pro taneema form bugs each part will proceed to grow into a newly peed gametophyte spores then enable mosses to spread and colonize new areas often some distance from the parent plant using both gametes and spores these unassuming members of the plant kingdom quietly proceed to thrive and multiply they have successfully spread from polar regions to the tropics and are equally at home in our cities or in the countryside perhaps a key to their success is their small size perhaps as due to their ancient lineage going back more than 400 million years to a time when plants were first colonizing the land whatever the reason these tough get attractive opportunists Oh many surprises interested observer