]]>
LearnNext
Get a free home demo of LearnNext

Available for CBSE, ICSE and State Board syllabus.
Call our LearnNext Expert on 1800 419 1234 (tollfree)
OR submit details below for a call back

clear

Bryophytes

21,380 Views
Have a doubt? Clear it now.
live_help Have a doubt, Ask our Expert Ask Now
format_list_bulleted Take this Lesson Test Start Test

Bryophytes - Lesson Summary

Bryophytes are called ‘the amphibians of the plant kingdom’ because they grow in soil, but need a moist habitat for sexual reproduction. The plant body, a haploid gametophyte is thallus-like and is attached to the substratum by rhizoids. . The plant body has both male and female gametophytes, which bear the male and female sex organs, respectively.

The male sex organs called the antheridia produce biflagellate antherozoids. The female sex organs called the archegonia produce a single egg. During fertilisation, the antherozoids from the antheridium swim in water to reach the egg inside the archegonium to form a zygote. The zygote, in turn produces a multicellular diploid sporophyte, which derives its nutrition from the gametophyte. Some cells of the sporophyte undergo meiosis to produce haploid spores, which germinate to produce a haploid gametophyte. 
 
Bryophytes are of two types - liverworts and mosses. Liverworts reproduce both asexually and sexually. They reproduce asexually through fragmentation of the thallus or through gemmae. Gemmae are green, multicellular, asexual buds that separate from the parent and develop into new individuals. They develop in small receptacles called gemma cups, located on the thallus. In sexual reproduction, the male and female sex organs are produced either on the same or on different thalli.
 
Funaria, Polytrichum and Sphagnum are common species of moss. In moss, the gametophyte stage is the dominant stage. The gametophyte stage has two sub-stages – the protonema and the leafy stage. In the protonema stage, the spore develops into a thread-like, creeping, green, branched and filamentous chain of cells. The second stage is the leafy stage, where the primary protonema develops into the secondary protonema as a lateral bud. The buds consist of upright and slender axes that bear spirally arranged leaves attached to the soil through branched rhizoids. The sexual organs develop during the leafy stage. Mosses reproduce vegetatively through fragmentation or through budding in the secondary protonema. In sexual reproduction, the male and female sex organs are produced at the apex of the leafy shoots. 

Comments(0)

Feel the LearnNext Experience on App

Download app, watch sample animated video lessons and get a free trial.

Desktop Download Now
Tablet
Mobile
Try LearnNext at home

Get a free home demo. Book an appointment now!

GET DEMO AT HOME