Big picture what is a bryophytewhat is a bryophyte. Before we can talk about the bryophyte life cycle, we should know what a bryophyte is. The first structure formed from spores in most mosses and many liverworts is a filamentous, algallike. Bryophyte biology by bernard goffinet cambridge core. The gametophyte haploid structures are shown in green, the sporophyte diploid in brown. Life cycles of bryophytes advanced ck12 foundation. If you know of any bryophyte books that are missing from the list please leave a message in the comments.
Bryophyte definition, characteristics, life cycle and examples. This interactive quiz and printable worksheet allow you to test your knowledge and identify. The first stage is the protonema stage, which develops directly from a spore. The tools necessary to identify the molecular genetic basis of this variation are now well. The zygote is the starting point of the next phase of the life cycle. Natural phenotypic variation is widely documented within and among populations of bryophyte species.
In other it is externally differentiated into stem and leaves, however there are no roots. When a spore germinates, it usually produces the protonema, which precedes the appearance of the more elaborately organized gametophytic plant, the gametophyte, which produces. All embryophytes have a life cycle that involves an alternation between sporophyte and gametophyte generations. The spores produced in a spore capsule are the result of sexual reproduction.
Characteristics of bryophytes life cycle and reproduction. A moss begins its life cycle when haploid spores are released from a sporophyte capsule and begin to germinate. Gametophytic generation is the prominent phase in life cycle in both groups 4. On germination the zygote forms the second diploid adult of the life cycle called sporophyte or sporogonium. A bryophyte is a type of green, seedless plant that includes the mosses, liverworts, and hornworts.
Each of the haploid 1 n spores is capable of developing into a multicellular, haploid individual, the gametophyte. Bryophyte, traditional name for any nonvascular seedless plantnamely, any of the mosses division bryophyta, hornworts division anthocerotophyta, and liverworts division marchantiophyta. Unlike vascular plants, in bryophytes the haploid gametophyte 1n is the dominating generation. Some bryophyte species have evolved special tissue which allows them to transport water and other substances through their tissue. Although individuals of the three bryophyte groups differ from one another morphologically and in other details, the moss life cycle shown in figure is typical of the group in general.
Mature gametophytes produce antheridia or archegonia, depending on sex. Estimating the duration of stages in the life cycle of bryophytes based on repeated censuses of. The standard bryophyte life cycle begins with a germinating bryophyte spore. The second stage is the leafy stage, which develops from the secondary protonema as a lateral bud. The life cycle of bryophytes bryophytes are diplohaplontic plants with a heteromorphic alternation of generations within the sporangium spores are formed by meiosis protonema and gametophores develop after germination antheridia and archegonia produce sperm and eggs after fertilization a new, attached sporophyte is formed. Mosses are widely distributed from pole to pole and occupy a broad range of habitats. Bryophyta characteristics, life cycle and examples of. It gives rise to diploid sporophyte, which however contains twice the number of paired chromosomes. The gametophytic phase produces the gametes and each cell of the gametophyte is haploid. The life cycle of bryophytes consists of an alternation of two stages, or generations, called the sporophyte and the gametophyte. 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 two sets of paired chromosomes. It is a creeping, green, branched and frequently filamentous stage.
Like all land plants embryophytes, bryophytes have life cycles with alternation of generations. A haploid gametophyte cell contains a fixed number of unpaired chromosomes. Like liverworts and hornworts, mosses possess a gametophytedominated life cycle. Antherozoids are produced in antheridia and eggs are produced in archegonia. The life cycle of bryophytes contains an alternation of two stages or generations, known as the gametophyte and the sporophyte.
The gametphyte is haploid and an independent plant at maturity. This stands in direct contrast to the tracheophyte life cycle, in which the diploid stage is dominant. The gametes formed by bryophytes swim with a flagellum, as do gametes in a few of the tracheophytes. Whenever a spore germinates, it usually generates the protonema, which precedes the look of the more elaborately arranged gametophytic plant. As do all plants, bryophytes alternate a gametophytic generation with a sporophytic one a sporic meiosis, a life cycle in which meiosis gives rise to spores, not. Diploid zygotes formed by the fusion of haploid sperm and. Bryophyta mosses, hepatophyta liverworts, and anthoceraphyta hornworts. These key innovations allowed plants to colonize the land, setting. In this article we will discuss about the gametophytic phase, reproduction and sporophytic phase in the life cycle of riccia. These key innovations allowed plants to colonize the land, setting off a series of spectacular adaptive radiations, first among bryophytes and later in vascular plants. Bryophyte is a nonvascular plant, small in size, undergoing a life cycle that alternates between haploid and diploid generations with a more dominant gametophyte phase gradstein, s. On estimating the duration of phenological stages in bryophytes. The bryophyte lifecycle consists of alternating generations between the haploid gametophyte and the diploid sporophyte. 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.
The following diagram gives one example of a bryophyte life cycle, that of the moss funaria hygrometrica. The predominant stage of the life cycle of a moss is the gametophyte which consists of two stages. Bryophytes basic biology basic biology inspired by life. Bryophytes are a type of green plant that includes the mosses, liverworts, and hornworts. The haploid spores are produced during this phase which on germination gives rise to the gametophytic plant body. Most bryophytes lack complex tissue organization, yet they show considerable diversity in form and. First, in all bryophytes the ecologically persistent, photosynthetic phase of the life cycle is the haploid, gametophyte generation rather than the diploid sporophyte. Aquatic bryophyte ecology bryophytes a reh e all land plants likely to have freshwater algal ancestor algal ancestor had floating eggs and. Measure your understanding of the bryophyte life cycle.
As do all plants, bryophytes alternate a gametophytic generation with a sporophytic one a sporic meiosis, a life cycle in which meiosis gives rise to spores, not gametes. The protonema, in turn, develops into the gametophyte stage, in which the plant develops leaflike structures. Their lifecycle is dominated by a gametophyte generation which provides support and nutrients for the spore producing growth form known as the sporophyte. The editors have collected many of the major bryological players and generated a tome of enormous merit. Cambridge core plant sciences bryophyte biology by bernard goffinet edited by a. During the gametophyte stage, haploid gametes male and female are formed in the specialized sex organs. True roots are absent in both groups of algae and bryophytes 5.
Similarities and difference between bryophyte and algae a. Repeated dichotomy results into a typically rosette like appearance figs. 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 the formation of additional cells. In vascular plants it is the sporophyte is the dominant, obvious stage. Aquatic bryophytes heather lintz botany and plant pathology oregon state university i.
Bryophyte simple english wikipedia, the free encyclopedia. In bryophytes liverworts, hornworts, and mosses, the gametophyte stage is dominant. Gametophytes produce haploid sperm and eggs which fuse to form diploid zygotes that grow into sporophytes. The life cycle of bryophytes is like all the other land plants embryophytes with alternation of generations. Bryophyte definition, characteristics, life cycle and. Introduction to bryophytes introduction to bryophytes. Chapter 22 bryophytes university of california, davis. The term bryophytes is a general, inclusive term for these three groups though they are only superficially related. Bryophytes evolved important advances in both phases of the land plant life cycle. The basic bryophyte life cycle begins with a haploid 1 n spore that germinates on moist soils and grows into a haploid gametophyte, the dominant life cycle stage. Bryophyte flora of north america all text free online and hardcopies available. 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. Read this lesson to learn about the surprisingly complex. Bryophytes plants without well developed vascular systems.
Sporophyte diploid generation is attached to and dependent on the gametophyte for the entire life cycle. A bryophyte has two forms that have different numbers of chromosomes. Like other plants, bryophytes change between two generations with different morphology and function heteromorphy. The spores begin their development, forming a matlike structure called a protonema. Nutrients absorbed through leaf cant grow tall water needed for fertilization use sperm, not pollen bryophyte characteristics haploid gametophyte dominate life form green, photosynthesizing diploid sporophyte shortlived depends on gametophyte for nutrients plant. The haploid stage, in which a multicellular haploid gametophyte develops from a spore and produces haploid gametes, is the dominant stage in the bryophyte life cycle. The other form is diploid and has paired chromosomes. Bryophytes occur in almost all terrestrial and freshwater habitats, and their ecological role may be considerable. The sporangiumthe multicellular sexual reproductive structureis present in bryophytes and absent in the majority of algae.
The plant body of riccia is gametophytic and gametophytes are fleshy, prostrate and dichotomously branched. The bryophytes seem to have evolved during a time in which gametophyte characteristics were important for plant survival, whereas the vascular plants evolved. Bryophyte generations alternate between a sporophytic generation, which means they use spores to reproduce, and a gametophytic generation, which means they use sperm and. In the majority of mosses, germination is exosporic, i. The genetic basis of natural variation in bryophyte model.
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