Question
Question: Define Bryophyta....
Define Bryophyta.
Solution
Bryophyte, is the traditional name for any seedless nonvascular plant namely any of the hornworts (division Anthocerotophyta) and liverworts (division Marchantiophyta), and mosses (division Bryophyta). Most of the bryophytes yet show diversity in ecology and form but lack complex tissue organization.
Complete answer:
As discussed above, Bryophytes are group that consist of three division: the liverworts, mosses and hornworts. Mosses come under division called Bryophyta (in Musci subdivision.)
Bryophytes are found in shaded and moist areas of hills. They are referred as amphibians of the plant kingdom because they live in soil but are dependent on water for sexual reproduction.
Its interesting to note that, their body is differentiated as, attached to substratum by multicellular or unicellular rhizoids, and are thallus-like erect. They can also survive drier environments. They produce enclosed structures for reproduction namely gametangia and sporangia, but they don’t produce seeds or flowers.
They reproduce via spores. They have life cycles with alternation of generation. Mosses, hornworts, and liverworts, spend most lives as gametophytes.
It's important to understand that, in Bryophytes and other divisions, A haploid gametophyte cell has a fixed number of unpaired chromosomes. This gives rise to diploid sporophyte, which contains twice the number of paired chromosomes. By fusion of haploid sperm and eggs (which are produced by gametophytes), diploid zygotes are formed. Diploid zygotes rise into a sporophyte.
Plants of this category have crude stems and leaves but don’t have roots. They have “rhizoids” which help plants to anchor to the surface, instead of roots.
Note: Always keep in mind, Bryophytes have three divisions namely, liverworts, mosses and hornworts. It does not have true vascular tissue. Mosses release their spores from leaves which then travel through water and give rise to new mosses in the new area.
Here the key point is that water is very essential for mosses to grow and spread. They can dry out entirely and survive. But when they get in contact with water they again revive and grow.