Question

Simplest sporogonium is of
(a) Riccia
(b) Cycas
(c) Marchantia
(d) Funaria

Answer 1

Hint: Sporogonium is made up of foot, seta, and capsule. The simplest form of sporogonium is made up of a capsule or sac- like structure only. Foot and seta are absent in these species. Other species of the Bryophytes family have differentiated sporogonium.

Complete answer:
Riccia species is the simplest sporogonium present in the liverwort family and Bryophyta division. The sporogonium of Riccia is in the form of a capsule or sac- like structure. There is an absence of foot and seta. The gametophyte is attached to the sporogonium. The sporogonium is dependent on the gametophyte for its nourishment and food as it has non- greener parts. The spore consists of remaining mother cells in the form of the capsule or spore- like sac. The mother cells have a meiotic division to form four haploid spores. These spores form a tetrahedral arrangement. Before the formation of spores, the inner walls of sporogonium and the covering layer are dissolved. The spores contain only a single layer of the covering around them. There is an absence of elaters.
- The sporogonium of Funaria consists of divided foot, seta, and capsule or spore sac.
- The foot of Funaria is attached to the gametophyte which helps in the absorption of food for the sporogonium.
- The sporophyte of Cycas is well divided into roots, stems, and leaves. It consists of the VAM system. Its sporophyte is dioecious. They have different male and female plants.
- Marchantia also falls under the division Bryophyta in the plant kingdom. The mature sporogonium consists of differentiated foot, seta, and capsule or spore- like sac. The foot is attached to the gametophyte for the absorption of food and for its nourishment.

So, the correct answer is ‘Riccia’.

Note: Sterile cells known as elaters are absent in species of Ricca. The sporophytic Riccia is dependent on the gametophyte for its food as it has no chloroplasts. Non-greener parts refer to the absence of chloroplast in the sporogonium.