2. Give two characterists and one example for each of the following
(v) Bryophyta
Answers
Give two characterists and one example for each of the following
(v) Bryophyta
Answer:
Characteristics of Bryophytes:
Plants occur in damp and shaded areas
The plant body is thallus like, i.e. prostrate or erect
It is attached to the substratum by rhizoids, which are unicellular or multicellular
They lack true vegetative structure and have a root-like, stem-like and leaf-like structure
Plants lack the vascular system (xylem, phloem)
Bryophytes show alternation of generation between independent gametophyte with sex organs, which produces sperm and eggs and dependent sporophyte which contains spores
The dominant part of the plant body is gametophyte which is haploid
The thalloid gametophyte is differentiated into rhizoids, axis and leaves
The gametophyte bears multicellular sex organs and is photosynthetic
The antheridium produces antherozoids, which are biflagellated
The shape of an archegonium is like a flask and produces one egg
The antherozoids fuse with egg to form a zygote
The zygote develops into a multicellular sporophyte
The sporophyte is semi-parasitic and dependent on the gametophyte for its nutrition
Cells of sporophyte undergo meiosis to form haploid gametes which form a gametophyte
The juvenile gametophyte is known as protonema
The sporophyte is differentiated into foot, seta and capsule.Eg-Liverwort