Cambridge core plant sciences bryophyte biology by bernard goffinet edited by a. Origin and evolution of sporophyte in bryophytes ch09 life sciences, botany, zoology, bioscience. Origin and evolution of bryophytes linkedin slideshare. A sporophyte develops from an egg, held within a flasklike archegonium, that has been fertilized and theres more about that process in the sexual reproduction page. The defining features of bryophytes are that their life cycle featuring alternating haploid and diploid generations with a dominant, branched gametophyte stage. The sporophytes of many moss species mature over somewhat more than a year but. The most complex bryophyte sporophytes also contain novel. Initially, the gametophyte was the larger, more apparent stage. Like all plants, the bryophyte life cycle goes through both haploid gametophyte and diploid sporophyte stages. The below mentioned article provides a note on bryophytes. The sporophyte of riccia is the simplest among all the bryophytes and has the least amount of sterile cells. In each cycle, a haploid gametophyte, each of whose cells contains a fixed number of unpaired chromosomes, alternates with a diploid sporophyte, whose cell contain. Todays descendants of these early plants reveal the traits that made them success. First, meiosis must be delayed in the zygote, which, as you recall, is.
Evolution of the sporophyte in brophytes slideshare. Major transitions in the evolution of early land plants. The evolution of body form in bryophytes request pdf. According to him, while the free germination of a spore tends to make it a gametophyte, the fertilized egg developing within constraints tend to make it a sporophyte.
Modern bryophytes almost certainly evolved from a single common ancestor, and they likely. Fossils of the hepaticopsida were previously not known before the carboniferous while the lower vascular plants the pteridophytes were known from a much earlier age. This theory was advocated by bower 1908 35 and supported by cavers 1910 and campbell 1940. Plants are multifarious organisms which show various degrees of evolution which ranges from plants that are not differentiated into leaves stems and roots like thallophytes to those that are fully differentiated, like the angiosperms. Recurrent evolution of dioecy in bryophytes mcdaniel 20. As descendents of embryophytes that diverged before tracheophytes appeared, bryophytes offer unique windows into the early evolution of land plants. Explorations of life history phenomena in bryophytes and a solid understanding of interrelationships among them are nec. The role of hybridization in evolution has been debated for more than a century regarding bryophytes mosses. Gametophyte is long lived among this group of plants. To study the evolution of sexuality in the mosses, we examined the patterns of evolution of dioecy and hermaphroditism using a generic. Another important evolutionary jump in the transition from such algae to bryophytes is to switch from the two freeliving gametophyte and sporophyte phases. The more parsimonious hypothesis of homology implies that a basal meristem present in the. Chart and diagram slides for powerpoint beautifully designed chart and diagram s for powerpoint with visually stunning graphics and animation effects. The anthocerotales developed as one line from the jungermanniales by elaboration of sporophyte while retaining the simple gametophyte.
Introduction to bryophytes download ebook pdf, epub. In bryophytes, the sporophytes are always unbranched and produce a single sporangium spore producing capsule. Complex morphologies diversified independently in both the haploid gametophyte and diploid sporophyte life cycle stages in different plant groups during. Genomes and evolution of charophytes, bryophytes, lycophytes. A sporophyte develops from an egg, held within a flasklike archegonium, that has been fertilized and theres more about that process in the sexual reproduction page the fertilized egg grows by. Which one of the following is a nonvascular embryophyte. The mature sporophyte in mosses has a similar anatomy to that in. Additionally, because they lack the efficient system of internal fluid transport found in tracheophytes, bryophytes require environmental moisture to ensure that all parts of the plant remain nourished.
It develops from the zygote produced when a haploid egg cell is fertilized by a haploid sperm and each sporophyte cell therefore has a double set of chromosomes, one set from each parent. The fertilized egg grows by the formation of additional cells. Two simple steps can account for the evolution of this new structure. Click download or read online button to get introduction to bryophytes book now. It gives rise to diploid sporophyte, which however contains twice the number of paired chromosomes. Overview of land plant evolution four main groups of land plants bryophytes pteridophytes gymnosperms and angiosperms groups are distinguished from algae by reproduction life cycle that involves the development of a multicellular embryo attached to the mother plant for its protection and nourishment. Eventually, the gametophyte stage became reduced to being only microscopic.
They are characteristically limited in size and prefer moist habitats although they can survive in drier environments. All land plants, and most multicellular algae, have life cycles in which a multicellular. This plant lecture explains about the bryophytes evolution. Bryophytes and in most pteridophytes the gametes are. Once plants like bryophytes became adapted to living on the land, evolution continued to select for plants that had traits favorable to this strange, dry territory. Introduction to bryophytes introduction to bryophytes.
The origin and early diversification of land plants. A haploid gametophyte cell contains a fixed number of unpaired chromosomes. The sporophyte is grown when released spores germinate in a new environment and begin dividing. Therefore, bryophytes species tend to show wider distributions than vascular plants. The sporophyte that develops from the embryo is barely noticeable. Read the introductory remarks and list of characteristics of the bryophytes p. An experimental evidence was provided by ward and wetmore 1954 when they partially released the pressure on the zygote by eliminating the surrounding prothallial cells. What is the alteration of generation in bryophytes botany. Mishler and churchill 1985 suggested an independent origin of the basal meristems in mosses and hornworts.
Introduction to bryophytes download ebook pdf, epub, tuebl. Given the basal position of these plants in embryophyte phylogeny, 24, 27 to consider this sporophyte less complex than those of pteridophytes is an oversimplification. Bryophytes were a pivotal step in land plant evolution, and their significance in the regulation of ecosystems and the conservation of biodiversity is becoming increasingly acknowledged. Recently however, hueber 1961 has discovered hepaticites devonicus fig. Diploid zygotes formed by the fusion of haploid sperm and. Freesporing plants have these shared characteristics. Gametophyte size ranges from three cells in pollen to several million in a lower plant such as moss. Unlike the multisporangiate indeterminate sporophyte of the tracheophytes, bryophyte sporophytes are unisporangiate and determinate. Theyll give your presentations a professional, memorable appearance the kind of sophisticated look that todays audiences expect. A science communication activity laboratory on chemical competition in peatland plants using the moss sphagnum insights into the biology and evolution of bryophytes in northeastern connecticut.
This site is like a library, use search box in the widget to get ebook that you want. Gene transfer by interspecific hybridization in bryophytes. For bryophytes, the gametophyte is the most obvious generation. In general, bryophytes species have wide geographic ranges that often span more than one continent figure 4, 5 and 6. The bryophytes show an alternation of generations between the independent gametophyte generation, which produces the sex organs and sperm and eggs, and the dependent sporophyte generation, which produces the spores. The life cycle of bryophytes is like all the other land plants embryophytes with alternation of generations.
Describe two adaptations that are present in mosses, but not hornworts or liverworts, which reflect steps of evolution. Bryophytes thrive in humid climates, but can be found all over the world, even in arid regions. Overview of land plant evolution four main groups of land plants bryophytes pteridophytes gymnosperms and angiosperms groups are distinguished from algae by reproduction life cycle that involves the development of a multicellular embryo attached to. The gametophyte haploid structures are shown in green, the sporophyte diploid in brown. Read genomes and evolution of charophytes, bryophytes, lycophytes and ferns by stefan rensing available from rakuten kobo. Like all land plants embryophytes, bryophytes have life cycles with alternation of generations. The gametophyte produces haploid spores with only have the genetic material of gametophyte cells. Evolution of sporophytes and gametophytes in bryophytes. Phloem conducts sucrose and other organic compounds throughout the plant. One generation is known as the gametophyte and the second is the sporophyte. Chapter 22 bryophytes university of california, davis. Winner of the standing ovation award for best powerpoint templates from presentations magazine. Worlds best powerpoint templates crystalgraphics offers more powerpoint templates than anyone else in the world, with over 4 million to choose from. Among these are the persistently chlorophyllous and nutritionally largely independent sporophyte, rhizoidlike present on the sporophyte foot, the longevity and large size of the sporophyte, and paleobotanic findings.
On the other hand, the members of the class bryopsida e. Plant diversity page pd3 how did the life stages of plants change during evolution. Recurrent evolution of dioecy in bryophytes mcdaniel. The plant life cycle has mitosis occurring in spores, produced by meiosis, that germinate into the gametophyte phase. The first bryophytes liverworts most likely appeared in the ordovician period, about. As the name implies, there is an embryonic stage in these organisms as contrasted with their closest relative of green algae all embryophytes have a life cycle that involves an alternation between sporophyte and gametophyte generations. Like all land plants embryophytes, bryophytes have life cycles with alternation of generations 9. Vascular tissue vascular plants dominate the natural landscape can achieve great heights because of roots and vascular tissue and nutrientconducting tissue xylem conducts water and dissolved minerals up from roots. Learn vocabulary, terms, and more with flashcards, games, and other study tools. The evolution of sporophyte in bryophytes as such is considered to have taken place by. Sporophyte evolution one of the most important innovations of early bryophytes was a multicellular sporophyte fig.
Pteridophytes constitute a significant and important group in the plant kingdom. Key words diploidy, evolution, haploidy, land plants, life cycle. Bryophytes are an informal group consisting of three divisions of nonvascular land plants. Bryophytes and tracheophytes are monophyletic and collectively called embryophytes. Evolution of the sporophyte in brophytes linkedin slideshare.
Traits shared by land plants, and lacking in the charophyceans 2. In contrast to vascular plants, the bryophyte sporophyte usually lacks a complex vascular system and produces only one sporecontaining organ sporangium rather than many. Our new crystalgraphics chart and diagram slides for powerpoint is a collection of over impressively designed datadriven chart and editable diagram s guaranteed to impress any audience. The spore bearing capsule, sporangium obtains its nutrition through a small stalk called seta. Evolution of sporophytes in bryophytes prema iswary. Purchase genomes and evolution of charophytes, bryophytes, lycophytes and ferns, volume 78 1st edition. This basic pattern of life cycle likely occurs through. There are two opposing theories regarding the evolution of sporophyte in bryophytes. The three groups of bryophytes are morphologically distinct from one anoth er chopra 1968, but it is rarely recog nized that such distinctions are due to fundamental differences in morpho. An analysis of the evolution of sporophyte branching in early land plants has been produced by rothwell 1995. In contrast to vascular plants, the bryophyte sporophyte usually lacks a complex vascular system and produces only one spore. In this group of organisms gametophyte is dominant while the sporophyte is restricted to the zygote 2.
Question bank for neet biology kingdom plantae bryophytes. Later, the sporophyte stage became more dominant and elaborate. According to this theory the primitive bryophytes were masslike in appearance. Then the inclination of capsules was measured using the free imaging. Bryophyta characteristics, life cycle and examples of. Smith 1955 the primitive bryophytic gametophyte was a simple thallose plant, and that the primitive sporophyte was the simple globose type. Some plants like the cryptogams thallophytes, bryophytes and pteridophytes are nonflowering and do not produce seeds, whereas the phenerogams are flowering. Bryophytes are an informal group consisting of three divisions of nonvascular land plants embryophytes. Ppt bryophytes and evolution powerpoint presentation. The sporophyte phase produces spores by meiosis within a. The sporophyte is nutritionally dependent on the former. Feb 06, 2016 1918 influenza pandemic survivor interview. The sporophyte of bryophytes is dependent on the gametophyte for water and nutrients and in most cases conspicuous as you can see in the image of leucolepis acanthoneuron to the left. Start a free trial of quizlet plus by thanksgiving lock in 50% off all year try it free.
First, meiosis must be delayed in the zygote, which, as you recall, is retained on the parent gametophyte in land plant ancestors. The three groups of bryophytes are morphologically distinct from one anoth er chopra 1968, but it is rarely recog nized that such distinctions are due to fundamental differences in morpho genetic design. Discerning the patterns of evolution in hermaphroditism and dioecy in mosses will provide insights into the relative importance of key population parameters in governing sexual systems in general. The life cycle of sexually reproducing eukaryotes consists of a haploid 1n and a diploid 2n phase. Alternation of generations occurs in plants, where the sporophyte phase is succeeded by the gametophyte phase. This introductory textbook assumes no prior knowledge of bryophyte biology, making it ideal for advanced undergraduate and graduate students, as well as. Bryophytes are small, non vascular land plants, that require water for reproduction.