Question

List the salient features of Bryophytes.

Answer 1

Salient features of Bryophytes : 

• The plant body of bryophyte is gametophyte and is not di erentiated into root, stem and leaf likestructure. 
• Most of them are primitive land dwellers. Some of them are aquatic (Riella, Ricciocarpus).
• The gametophyte is conspicuous, long lived phase of the life cycle. Thalloid forms are present inliverworts and Hornworts. In Mosses leaf like, stem like structures are present. In Liverworts thallus grows prostrate on the, ground and is attached to the substratum by means of rhizoids. 
• Vascular tissue like xylem and phloem are completely absent, hence called Non vascularcryptogams. 
• Vegetative reproduction takes place by the formation of adventitious buds (Riccia fiuitansi. Tubersdevelop in Anthoceros. Gemmae are formed in Marchantia.
• Sexual reproduction is Oogamous. Antheridia and Archegonia are produced in a protective coveringand are multicellular. 
• The antheridia produces biflagellate antherozoids which swims in thin film or' water and reach thearchegonium and fuse with the egg to form diploid zygote. 
• Water is essential for fertilization. 
• The zygote is the first cell of the sporophyte generation. It undergoes mitotic division to formmulticellular undi erentiated embryo. The embryogeny is exoscopic. The embryo divides and give rise to sporophyte. 
• The sporophyte is dependent on gametophyte. 
• It is di erentiated into three recognizable parts namely foot, seta and capsule. The foot is the basalportion and is embedded in the gametophyte through which water and nutrients are supplied for the sporophyte. The diploid spore mother cells found in the capsule region undergoes meiotic division and give rise to haploid spores. In some sporophytes Elaters are present and help in dispersal of spores Eg: Marchantia
• Bryophytes are homosporous. 
• The zygote, embryo and the sporogonium constitute sporophytic phase. The green long livinghaploid phase is called gametophytic phase The haploid gametophytic phase alternates with diploid and shows heterologous alternation of generation.