Roots, stems and leaves ferns, horsetails, clubmosses. Alternation of generation in pteridophytes biyani group. In contrast to vascular plants, the bryophyte sporophyte usually lacks a complex vascular system and produces only one spore. Alternation of generations is a type of life cycle found in terrestrial. In bryophytes, the dominant phase in the lifecycle is the gametophyte, for the sporophyte is retained upon it throughout its life and is either partially or completely dependent on it for nutrition. However, in pteridophytes, the main plant body is a sporophyte which is differentiated into true root, stem and leaves. In bryophytes mosses and liverworts, the dominant generation is haploid, so that the gametophyte comprises what we think of as the main plant. In bryophytes, the neck of archegonium is with 5 to 6 neck canal cells. The other form is diploid and has paired chromosomes. Fern spores are catapulted into the air, and the spores develop into heartshaped haploid gametophytes that contain both male and female sex organs.
The simplest form of alternations of generations is found in the fern, as seen below. Plant kingdom thallophytes algae bryophytes pteridophytes. Bryophytes mosses, liverworts, hornworts vascular plants well developed tissues that conduct and distribute water. Sep 19, 2014 alternation of generations in different plants depends on type of plant bryophytesmosses and ferns dominant generationhaploid phase main plant body is composed of gametophyte pteridophytes and gymnosperms dominant generation diploid phase main plant body is composed of sporophyte.
What is the alteration of generation in bryophytes botany. Difference between bryophytes and pteridophytes difference wiki. Difference between bryophytes and pteridophytes major. Aug 12, 2014 alternation of generations life cycle duration. O they show heteromorphic alternation of generation with prominent sporophytic and gametophytic phases.
The gametophytic and sporophytic generations alternate with each other regularly in the life cycle. In ferns the gametophyte is a small flattened autotrophic prothallus on which the young sporophyte is briefly. Pteridophyta characteristics, life cycle, classification. In contrast to vascular plants, the bryophyte sporophyte usually lacks a complex vascular system and produces only one sporecontaining organ sporangium rather than many. Contrary to it in pteridophytes the sporophyte is the dominant generation, for it very soon becomes independent of the gametophyte prothallus and grows to a much greater size. They play an important role in plant succession on bare rockssoil. These are the first true land plants in the evolution of the plant kingdom. Key difference bryophytes pteridophytes vs gymnosperms the kingdom plantae is one of the most widespread kingdoms with over 300,000 different species.
On the undersurface of its fronds or leaves, its cells undergo meiosis to create haploid cells. Alternations of generations bryophytes, pteridophytes, gymnosperms, angiosperms plant organization the amazing plant race phylum porifera phylum cnidaria phylum platyhelminthes phylum nematoda phylum annelida phylum mollusca phylum arthropoda phylum echinodermata phylum chordata conclusion. Bryophytes, pteridophytes, gymnosperms, angiosperms pages. Choose from 109 different sets of bryophytes, pteridophytes, gymnosperms, angiosperm flashcards on quizlet. Ferns can be used to illustrate the life cycle stages common to all pteridophytes. There is a great diversity of life history traits within each of these. Similarities both have the heteromorphic alternation of generations. The way in which the alternation of generations occurs in plants depends on the type of plant. Alternation of generation in bryophytes lecture, bsc botany by dr. They exhibit alteration of generations where the gametophyte is dominant upon the sporophyte. Mar 08, 2016 the pteridophytes are found in cool, damp, shady places though some may flourish well in sandysoil conditions. In ferns, the diploid sporophyte is much larger, but the haploid gametophyte is. Alternation of generations biology encyclopedia cells.
He observed that in mosses and ferns there are two types of morphologically distinct individuals present in the life cycle. Plants are eukaryotic, multicellular, autotrophic organisms that are capable of. O the main plant body of pteridophyte is the sporophytic plant diploid. Bryophytes show heteromorphic alternation of generations. Bryophyta and pteridophyta is strictly homologous with the sexual generation, and that the alternation in these groups differs only in its regularity from the. They are classified into chlorophyceae, phaeophyceae and rhodophyceae. Alternation of generations, also called metagenesis or heterogenesis, in biology, the alternation of a sexual phase and an asexual phase in the life cycle of an organism. They usually occur in damp, humid and shaded localities. Pteridophytes pteridophytes is a general term for the vascular, free. Pteridophytes biology encyclopedia plant, body, different. Alternation of generations simple english wikipedia, the. Gametophyte generally lacks vascular tissue and is predominantly parenchymatous.
Chapter 3 plant kingdom gametophytic generation diploid. Similar to the life cycle of seed plants, the pteridophytes also involves the alternation of generations in its life cycle. Bryophytes are all pretty small plants as they are limited in size by poor transport methods for water, gases and other compounds. In gymnosperms, the seeds are not covered by fruit walls. Here, the dominant sporophyte produces spores through meiosis. Bryophytes, pteridophytes, gymnosperms and angiosperms.
The sporeproducing phase in the life cycle of a plant. The gametophyte generation forms gametes by mitosis. Jun 20, 2015 in which maximus describes the ubiquitous process of alternation of generations. Homologous versus antithetic alternation of generations and the. May 26, 2017 what is the difference between bryophytes and pteridophytes. Like all land plants embryophytes, bryophytes have life cycles with alternation of generations. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. 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. Alternation of generations two multicellular body forms. They are chlorophyllous, autotrophic, archegoniate, embryophytic and tracheophytic. Diploid sporophyte is physically and nutritionally dependent on the gametophyte. 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. For example, in all bryophytes the gametophyte generation is dominant and the sporophyte is dependent on it. Bryophytes are a division of nonvascular land plants, which are classified under the kingdom of plantae.
The plant body of bryophytes is more differentiated than that of algae. This means that a diploid generation the sporophyte, which produces spores is followed by a haploid generation the gametophyte or prothallus, which produces gametes. Both have the heteromorphic alternation of generations. The life history of bryophytes involves an alternation between sporophytic and gametophytic generations that differ in form and function. Hofmeister 1862 wrote that mosses and ferns exhibit remarkable instances of a regular alternation of two generations very different in their organization. Bryophytes plants without well developed vascular systems. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Alternation of generations is defined as the alternation of multicellular diploid and haploid forms in the organisms life cycle, regardless of whether or not these forms are freeliving. Difference between bryophytes and pteridophytes with. This is in contrast to animals, in which the only multicellular phase is the diploid organism such as the human man or woman, whereas the haploid phase is a. Jun 21, 2017 important characteristic features of division pteridophyta with examples. May 26, 2017 a read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext.
Alternations of generations bryophytes, pteridophytes, gymnosperms, angiosperms plant organization the amazing plant race phylum porifera phylum cnidaria phylum platyhelminthes phylum nematoda phylum annelida phylum mollusca phylum arthropoda phylum echinodermata. Alternation of generations refers to the occurrence in the plant life cycle of both a multicellular diploid organism and a multicellular haploid organism, each giving rise to the other. The sexuality of pteridophytic gametophytes can be classified as follows. On account of their complex dependence on external water for completing their life cycle, bryophytes along with pteridophyte are regarded as amphibians of plant kingdom.
Just as with bryophytes and spermatophytes seed plants, the life cycle of pteridophytes involves alternation of generations. One is haploid x or gametophytic phase produces gametes. The gameteproducing phase in the life cycle of a plant. In mosses and their relatives bryophytes, the haploid gametophyte is the dominant generation, and the diploid sporophytes are sporangiumbearing stalks growing from the gametophytes. Bryophytes require water to complete their sexual reproduction.
Pteridophytes show a true alternation of generations. Morphology, reproduction, life cycle and alternation of generation of pteridophytes. May 26, 2017 gametophytes of bryophytes are always autotrophic and macroscopic. These colonies are made up of many smaller individuals that work together to absorb and retain water. Todays descendants of these early plants reveal the traits that made them success.
In pteridophytes, sporophyte and gametophyte are separated from each other. Alternation of generations also known as metagenesis is the type of life cycle that occurs in. Transfer of pollen from the anther to the stigma of a plant. They reproduce vegetatively by fragmentation, asexually by spore. The life cycle of pteridophytes is a continuous reproductive process that is dominated by the sporophyte sexual stage of the alternation of generations. You have no alternation of generations in the sense we are discussing in diatoms, dinoflagellates, chrysomonads, oomycetes if lumped into algae, and more. Liverworts, hornworts, and mosses are the examples of bryophytes. Pdf file of the hand out provided see file memoryppt. The alternative view that the sporeproducing generation in. In the life cycle of these plants, there exist two distinct phases. Division monilophyta ferns, horsetails, whisk ferns.
Alternation of generation in pteridophytes pteridophytes also show heteromorphic alternation of generation like bryophytes but th e dominant phase is. They are flowerless plants exhibiting alternation of two distinct and dissimilar generations, the first is a non sexual, spore bearing sporophytic generation. In the case of bryophytes the gametophyte generation is conspicuous and longerlived phase of the lifecycle in comparison to that of sporophyte generation. Characteristics of pteridophytes, morphology of pteridophytes, reproduction of pteridophytes, homosporous and heterosporous pteridophytes, megaspore and microspores, gametophytes of pteridophytes, fertilization, zygote and embryo of pteridophytes, life cycle and alternation of generation. Most bryophytes are found in damp environments and consist of three types of nonvascular land plants. The spores are produced by the sporangia in the spore. A division of the plant kingdom, comprising the vascular cryptogams. Sporophyte diploid generation is attached to and dependent on the gametophyte for the entire life cycle. Pteridophytes general characteristics free online biology. In this article we will discuss about the similarities and difference between pteridophytes and bryophytes. Difference between bryophytes pteridophytes and gymnosperms. However, these cells do not immediately unite with others to recreate the diploid state. So they are called amphibians of the plant kingdom 5.
O the gametophytic and sporophytic generations are two independent plants not physically connected. Pteridophytes exhibit a welldefined heteromorphic alternation of generations. The gametophyte is dominant in bryophytes whereas the sporophyte is dominant in pteridophytes. When you speak in genetic terms, it is the rotation in between the haploid and diploid stages.
Even the largest moss can only grow as tall as 50cm but much larger colonies of bryophytes can often be found. Alternation of generations in the lifecycle of a bryophyte biology. At the time of sporogenesis the reduction division takes place and the haploid spores are formed which represent the first stage of the gametophyte generation. The two generations or life cycles that occur are called the sporophyte generation and the gametophyte generation. In bryophytes, antheridium is stacked while in pteridophytes, it is sessile. There is a regular feature of alternation of generations. It is the dominant and independent phase of the life cycle. General characteristics of pteridophytes key points easy.
Pdf difference between bryophytes and pteridophytes. Difference between bryophytes and pteridophytes definition. Bryophytes and pteridophytes exhibit an alternation of generations in their life cycles. Pteridophytes exhibit a welldefined heteromorphic alternation of. Life history always encompasses a heteromorphic alternation of generations. Learn bryophytes, pteridophytes, gymnosperms, angiosperm with free interactive flashcards. Alternation of generations in the lifecycle of a bryophyte. Macromitrium, and in the heterosporous pteridophytes and all seed plants, the sex of the gametophytes is firmly correlated with differences in spore. Difference between bryophytes and pteridophytes with similarities. In some species, such as the alga ulva lactuca, the diploid and haploid forms are indeed both freeliving independent organisms, essentially identical in.
It bears the sexual reproductive organs which produce gametes, i. Useful notes on alternation of generations of pteridophytes. In this the haploid plant body is gametophyte and it is dominant phase. Antheridia male and archegonia female are the sex organs of bryophytes. A bryophyte has two forms that have different numbers of chromosomes. Bryophyte simple english wikipedia, the free encyclopedia. Bryophyte definition, characteristics, life cycle and. Hence the whole mechanism is called alternation of generations. You may recall that in bryophytes the dominant phase in the life cycle is the gametophytic plant body. Bryophytes are a group of plant species that reproduce via spores rather than flowers or seeds. Bryophyta and pteridophyta is strictly homologous with the sexual generation, and that the alternation. Both bryophytes and pteridophytes exhibit alteration of generations. Alternation of generation term used by hofmeister in 1851.
The pteridophytes include the ferns, horsetails, and the lycophytes clubmosses, spikemosses, and quillworts. In bryophytes, where the two generations are morphologically different, the type of alternation of generations is known as heteromorphic. Alternation of generation in pteridophytes biyani group of colleges. Bryophytes are also called amphibians of the plant kingdom because these plants can live in soil but are dependent on water for sexual reproduction. Bryophyte definition, characteristics, life cycle and examples. The haploid phase n is the gametophyte or sexual generation. Plant life cycles and alternation of generations topprguides. The two phases, or generations, are often morphologically, and sometimes chromosomally, distinct. However, the pteridophytes differ from mosses and seed plants in that both generations are independent and freeliving.
463 222 1258 872 809 539 1233 1152 650 1146 1008 1230 1448 804 964 1216 658 1311 1005 18 162 1131 1526 803 283 1123 11 1118 1327 453 618 530 1122 973 598 1254