Question
Question: The peristome in _funaria_ consists of at maturity A. One series of curved narrow triangular teeth...
The peristome in funaria consists of at maturity
A. One series of curved narrow triangular teeth, 16 in number.
B. One series of curved narrow triangular teeth,32 in number.
C. Two series of curved narrow triangular teeth, 8 teeth in each.
D. Two series of curved narrow triangular teeth, 16 teeth in each.
Solution
Peristome is the structure that surrounds an opening of organ, it acts as an anatomical feature, it present just below the operculum that consists of two overlapping circles of peristomal teeth which are of same radii and opposite to each other.
Complete answer:Funaria is a genus of plant kingdom that belongs to phylum Bryophyta. It consists of 210 species of mosses. The moss plant grows in a shady and cool place, in dense patches in rainy seasons. Their height is around 3 to 5 cm with differentiated stem, leaves and rhizoids with septa. These plants are autotrophic, multicellular, amphibious and shade-loving plants without vascular systems, which reproduce via spore formation and also show alternation of a generation which has a gametophytic and sporophytic stage.
The peristome lies below the operculum, which consists of two sets of conical teeth, which are present opposite to each other, the peristomial teeth close to the opening of the spore sac, that is attached to the base of diaphragm or rim. The peristomal teeth guard the mouth of theca region to decrease the releasing of spores. The outer side of peristomal teeth are hygroscopic and change according to the presence of humidity.
Hence the correct option is D.
Note: Bryophytes plants are the three divisions of the non-vascular land plants that are known as liverworts, hornworts and mosses, and they consist of 20,000 plant species and generally found in moist habitat like near ponds or rivers. This plant phylum bears spores rather than flowers or seeds for reproduction.