Question

Sporophyte of Riccia contains
A. Spores, elaters and nutritive cells
B. Spores and nutritive cells
C. Elaters and spores
D. Spores only

Answer 1

Hint:- Riccia is described as an aquatic, thallose liverwort. The capsule of Riccia remains lodged in the thallus of gametophytes. The sporophyte of Riccia is very simple because it contains only capsules. It lacks both the foot and seta.

Complete step-by-step solution:-
The sporophyte of bryophytes such as moss, liverwort or hornwort generally consists of one foot, seta and capsule.The mature capsule of Riccia is filled with spores and mixed with sterile cells or elaters. They open into valves by splitting.Elaters are described as the diploid, spindle-shaped, elongated, and hygroscopic structures having two spiral bands. These bands help to disperse spores.
In certain liverworts, all spore mother cells do not develop spores. Instead, some spore mother cells abort to become sterile and nutritive cells. These nutritive cells help to nourish the spores that grow. For example, in Riccia and Sphaerocarpa.
Thus, the correct option is (B). Spores and nutritive cells.

Additional information: The sporophyte of Riccia includes a peripheral layer of cells. It forms the wall of the capsule and a central mass of the mother cells, which contains spores.
The first generation of the sporophyte cells is a diploid zygote. After fertilization, the cells secrete a membrane around it. This enlarges in size and almost fills the centre cavity.

Note:- The sporogenous cells are responsible for the generation of spore mother cells. The mother spore cells are diploid and undergo meiotic division to form tetrads. The tetrad is composed of four spores. The spores are haploid in nature. The spores released from the sporogonium when the thallus decay.