A typical bryophyte life cycle although individuals of the three bryophyte groups differ from one another morphologically and in other details, the moss life cycle shown in. Pdf lifecycle graphs and matrix modelling of bryophyte. The moss gametophyte is the dominant stage in its life cycle. A haploid cell has one set of chromosomes, a diploid cell has two. The gametophyte of some bryophyte species reproduces asexually, or vegetatively, by specialized masses of cells gemmae that are usually budded off and ultimately give rise to gametophytes. Unlike vascular plants, in bryophytes the haploid gametophyte 1n is the dominating generation. The life cycle of bryophytes is characterized by distinct alternation of generations in which the gametophyte is the dominant stage of the life cycle. Gametophyte generation represents by a prothallus, which is green and photosynthetic produced by a spore of the sporophyte. First, in all bryophytes the ecologically persistent, photosynthetic phase of the life cycle is the haploid, gametophyte generation rather than the diploid sporophyte. The term bryophytes is a general, inclusive term for these three groups though they are only superficially related.
The gametophytes develop gametangia on special branches or at the tip of the main shoot. Their life cycle is dominated by a gametophyte generation which provides support and nutrients for the spore producing growth form known as the sporophyte. Mosses, liverworts and hornworts ppt what are bryophytes. The bryophyte lifecycle consists of alternating generations between the haploid gametophyte and the diploid sporophyte. The bryophytic life cycle was established by the elaboration of the gametophytic plant and the sporophytic plant becoming a parasite on the gametophyte. Gametangia produce the gametes eggs and sperm during the sexual part of the life cycle. Measure your understanding of the bryophyte life cycle. This page will start with the bryophyte life cycle in a nutshell.
Difference between bryophytes and pteridophytes bryophytes. During the gametophyte stage, haploid gametes male and female are formed in the specialized sex organs. Diploid zygotes formed by the fusion of haploid sperm and eggs produced by gametophytes. What is the structure of antheridium and archegonium of bryophyta. In each cycle, a haploid gametophyte, each of whose cells contains a fixed number of unpaired chromosomes, alternates with a diploid sporophyte, whose cell. Life strategies and adaptations in bryophytes from the near and middle east 74 irradiation solitary plants annual shortturf cushion tall turf fan, mat, pendant, tail, weft xeric habitats mesic to hygric habitats humidity drought stress high low low high figure 1. Like all plants, the bryophyte life cycle goes through both haploid gametophyte and.
Mehras conception of the origin of the bryophytes and also of the pteridophytes described more is shown. Read this lesson to learn about the surprisingly complex. The leafy shoot of mosses is haploid and thus part of the gametophyte generation. The gametophyte in bryophytes is green and responsible for photosynthesis. The fern life cycle requires two generations of plants to complete itself. Mature gametophytes produce antheridia or archegonia, depending on sex. Bryophyte generations alternate between a sporophytic generation, which means they use spores to reproduce, and a gametophytic generation, which means they use sperm and. Bryophyte and pteropyte life cycles 834 words 123 help me. Difference between bryophytes and ferns compare the.
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. In bryophytes such as the liverwort marchantia, gametophytes produce organs for sexual reproduction. The gametphyte is haploid and an independent plant at maturity. Bryophytes are a type of green plant that includes the mosses, liverworts, and hornworts. When they unite, the resulting cell is diploid and the ensuing embryo continues its development as a diploid individual. These key innovations allowed plants to colonize the land, setting. Although this diplohaplontic life cycle shows great variations in the different taxonomic groups with regard to the dominance of the gametophyte in bryophyta s. If you know of any bryophyte books that are missing from the list please leave a message in the comments. In bryophytes, where the two generations are morphologically different, the type of alternation of generations is known as heteromorphic. Alteration of generations is defined as a life cycle in which there is both a multicellular diploid form, the sporophyte, and a multicellular haploid form, the gametophyte. A typical bryophyte life cycle 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. The following diagram gives one example of a bryophyte life cycle, that of the moss funaria hygrometrica.
During the gametophyte stage, haploid gametes male and female are formed in the specialized. The 25 species on this poster illustrate both the diversity of illinois bryophytes and the variety of microhabitats in which they. The term bryophyta is used as a collective name to represent a group of plants that includes the mosses musci, hornworts and liverworts hepaticae growing predominantly in amphibious environment. Sporophyte diploid generation is attached to and dependent on the gametophyte for the entire life cycle. It gives rise to diploid sporophyte, which however contains twice the number of paired chromosomes. Remember, bryophytes lack vascular tissue, so they do not possess true leaves, roots, or stems like vascular plants. The life cycle of bryophytes consists of an alternation of two stages, or generations, called the sporophyte and the gametophyte. They live as understory components on the ground or as epiphytes in forests worldwide, but flourish most luxuriantly in moist warm. Like all land plants embryophytes, bryophytes have life cycles with alternation of generations. One generation is diploid, meaning it carries two identical sets of chromosomes in each cell or the full genetic complement like a human cell. The liverworts and mosses grow on soil, on damp sand, on rocks, and on the trunks and trunks of standing and prostrate trees. Difference between bryophytes and pteridophytes major. Life cycles of bryophytes advanced ck12 foundation. Life cycle graphs and matrix modelling of bryophyte populations article pdf available in lindbergia 272.
This is a basic explanation of the lifecycle of bryophytes. 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. Chapter 22 bryophytes university of california, davis. The sporophyte is the diploid stage of the pteridophyte life cycle. Reproduction in bryophytes 75 are caused during sporophyte development without the protection of a calyptra, resulting in decrease or no production of offspring. Most bryophyte species are found in only one microhabitat, although some species are widespread. Life strategies and adaptations in bryophytes from the.
Bryophyte life cycle the bryophyte lifecycle consists of alternating generations between the haploid gametophyte and the diploid sporophyte. Ecology of bryophytes as descendants of the early land plants, bryophytes have retained the ability to adapt to a variety of habitats and environments. Read the introductory remarks and list of characteristics of the bryophytes. The life cycle of bryophytes consists of two distinct phases the gametophytic phase and the sporophytic phase.
Bryophytes general characters ppt characteristics of bryophyta. Bryophytes evolved important advances in both phases of the land plant life cycle. Like liverworts and hornworts, mosses possess a gametophytedominated life cycle. The haploid gametophyte is dominant, long lived, green and independent whereas the diploid sporophyte is short. 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. 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. However, unlike bryophytes, ferns have a dominant sporophyte generation that is diploid. Some bryophyte species have evolved special tissue which allows them to transport water and other substances through their tissue. A haploid gametophyte cell contains a fixed number of unpaired chromosomes. The photosynthetic portion of a bryophyte is called a thallus.
Pteridophyte life cycle just as with bryophytes and spermatophytes seed plants, the life cycle of pteridophytes involves alternation of generations. The life cycle of bryophytes is like all the other land plants embryophytes with alternation of generations. Bryophyte definition, characteristics, life cycle and. This interactive quiz and printable worksheet allow you to test your knowledge and identify.
In the common haircap moss, polytrichum commune shown here, there are three kinds of shoots. Later, algae, fungi and lichens were placed in a separate division thallophyta and liverworts, mosses in division bryophyta. The details of their alternations of generation vary as well, although both have diploid and haploid stages. Bryophyte definition, characteristics, life cycle and examples. Bryophytes plants without well developed vascular systems. Brochure on the bryophytes of northeastern connecticut. Bryophyta characteristics, life cycle and examples of.
1581 941 1300 690 631 1373 1308 823 1515 1056 109 1222 1447 611 8 460 281 301 513 1071 946 661 900 1320 690 687 392 78 368 607 1383 1495 125 1162 492 573 1065 1138 543 1095 59 583 1375