The introduction of Bryophytes

The Bryophytes

The Bryophytes are Mosses , Liverworts, & Hornworts Damnjanović Ivana. Bryophyte is a traditional name used to refer to all land plants that do not have true vascular tissue and are therefore called "non-vascular plants".They have no wood to lend them structural support, nor do they have large leaves or showy cones, or flowers.
Bryophytes are gametophyte dominant, meaning that the more prominent, longer-lived plant is the haploid gametophyte. The diploid sporophytes appear only occasionally and remain attached to and nutritionally dependent on the gametophyte are called sporangium and Spores.
Absence of specialized tissues for transporting water and dissolved food throughout the organism limits terrestrial forms to being very short plants, since the only way to move substances through the plant body is by osmosis and diffusion from surface moisture. Bryophytes do not have roots but have rhizoids, which are relatively simple, sometimes multicellular filaments of thin-walled cells.
Reproduction and Life cycle Vegetative reproduction A piece that breaks off a gametophyte and then lands in suitable habitat will grow into a new gametophyte. The breakage may be accidental, such as animal trampling or erosion leading to fragmentation of an existing bryophyte colony.

                                      

Sexual Reproduction 

                 

This cycle of fertilization and meiosis involves an alternation of generations between the haploid gamete-producing stage (gametophyte) and the diploid organism (sporophyte). In the bryophytes, it is the haploid gametophyte that produces the leaves and thali and therefore predominates.
 The process requires the production of male gametes (sperm), female gametes (eggs), and some means of getting the sperm to the eggs. The gametes are produced on the gametophytes. The sperm are produced within tiny, typically stalked, club-shaped structures called antheridia. Each antheridium produces numerous sperm.
The eggs are produced in tiny, typically somewhat flask-like structures called archegonia. Each archegonium holds one egg (in a swollen section called the venter). The sperm enters through the channel in the narrower, tubular section (or neck).
 A fertilized egg in an archegonium develops into the sporophyte. The sporophyte consists of a spore-containing capsule that, depending on the species, maybe stalked or stalkless. Each spore contains a mix of genes from the two parents and successful germination will give rise to a new gametophyte.

                            
The 3 types of Bryophytes Mosses ,Liverworts, Hornworts
Mosses

Mosses are found in soil, rocks, tree bark.

•  It Help to form soil.
•  Colonize rocky sites.
•  Prevent soil erosion .
•  It grows packed together in dense colonies.
•  The Moss Body is called the thallus.
•  Rhizoids are hair-like absorptive structures that do not have TRUE roots, stems, or leaves. 
• Many mosses have separate sexes: male plants and female plants. 
• The gametophyte generation is dominant.This does not mean that mosses are not important; in fact, mosses play important roles in reducing erosion along streams, water and nutrient cycling in tropical forests, and insulating. 

                             

                  
Liverworts

• A liverworts is flowerless spore producing plant.The shape of these leaves similar to the lobes of liver.
• Plant body called Thallus i.e a body that lacks root stems or leaves
•  Liverworts get their name from their liver-shaped thallus.
•  Gemmae – Asexual reproductive structure of liverworts – Borne in a saucer-shaped structure – gemmae cup.
• Marchantia polymorpha
• Location: fields & roadsides -Thalloids - 1-2 cm 
• Sporophyte generations form hornlike projections out of the gametophyte.                                                       
  
  
  

  Hornworts

• Hornworts also knwn as ''Anthocerotae'', they are resemble to liverworts but distinguish by their sporophytes.
• This is the most advance group .
• The sporophyte has stomata and chloroplasts and can undergo photosynthesis.
• Sporophyte can continue to survive even often the death of gametophye.                                                                                                                                                               
  
  
                              
•  Uses of bryophytes                                                                                                                              
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