What is the structure of Riccia?
What is the structure of Riccia?
The gametophytic plant body of Riccia is a dichotomously branched dorsiventral prostrate thallus. In terrestrial habits, the plants usually occur in a rosette form due to the presence of a number of dichotomies that grow together from one place (Fig. 6.1 A-C). These rosettes are up to 15 cm in diameter.
How do Riccia reproduce?
The reproduction in Riccia takes place by means of (1) vegetative and (2) sexual methods. Vegetative Reproduction, By the death and decay of the older parts of the thallus, By adventitious branches, By cell division or gemma formation, By tubers, By thick apices.
What is the life cycle of a Riccia?
The life cycle of Riccia shows regular alternation of gametophytic and sporophyte generations. The two generations are morphologically different hence this type of alternation of generation is known as heteromorphic.
What is Riccia Gametophyte?
The gametophytic generation of Riccia consists of the green thallus plant, the sex organs and the gametes. This generation starts with the spores and ends with the fertilisation. The gametes are the last structures produced during the phase. The fusion of gametes leads to the formation of zygote.
What reproduction is in Riccia?
Plants are usually monoicous, and sexual reproduction is by antheridia and archegonia. Asexual reproduction occurs by spores, by fragmentation of the rosettes, and by formation of apical tubers. Spores are large (45 to 200 µ) and formed in tetrads….
| Riccia | |
|---|---|
| Genus: | Riccia L., 1753 |
| Species |
What is the division of Riccia?
Riccia belong to the a) Thallophyta division.
What is Sporophyte in Riccia?
The riccia sporophyte consists of a peripheral layer of cells that form the wall of the capsule and a central mass of the mother cell that contains spores. The diploid zygote is the first generation of sporophyte cells. The upper cell is called the epibasal cell, and the lower cell is called the parabasal cell.
What is male reproductive structure in Riccia?
The sex organs in bryophytes (Riccia, Funaria), are multicellular and jacketed. The jacket of sterile cell around the sperm and egg is an adaptation to a life on land. The male reproductive organs are antheridia and female reproductive organs are archegonia.
Which is the first cell of sporophyte generation in Riccia?
The diploid zygote is the first generation of sporophyte cells. Shortly after the fertilization this cell secretes a membrane around it and enlarges in size and almost fills the center cavity. Subsequently, it undergoes division and hits the two-celled stage.
What is the habitat of Riccia thallus?
3.1 Distribution and Habitat Most of the species of Riccia are terrestrial while few are aquatic in nature. The terrestrial species grow on clayed damp soil or tree trunks or wet walls while aquatic species occurs as free floating or submerged in pools, ponds or lakes.
What is Riccia Sporophyte?
What is riccia in botany?
Riccia is a genus of liverworts in the order Marchantiales. These plants are small and thalloid, that is not differentiated into root, stem and leaf. The thallus is dorsiventrally differentiated. Its upper (dorsal) surface is green and chlorophyll-bearing, with a mid-dorsal longitudinal sulcus (furrow or groove).
What is the sporophyte of Riccia?
One of the more than 100 species in this genus is the “slender riccia” (Riccia fluitans), which grows on damp soil or, less commonly, floating in ponds, and is sometimes used in aquariums. The sporophyte of Riccia is the simplest amongst bryophytes. It consist of only a capsule, missing both foot and seta, and does not perform photosynthesis.
What is the scientific name of Riccia?
For the Italian “comune”, see Riccia, Molise. Riccia is a genus of liverworts in the order Marchantiales. These plants are small and thalloid, that is not differentiated into root, stem and leaf.
What is the mode of reproduction in Riccia?
Riccia. Asexual reproduction occurs by spores, by fragmentation of the rosettes, and by formation of apical tubers. Spores are large (45 to 200 µ) and formed in tetrads. One of the more than 100 species in this genus is the “slender riccia” ( Riccia fluitans ), which grows on damp soil or, less commonly, floating in ponds,…
Why is the thallus dimpled in Riccia?
Air pores occasionally break through the dorsal surface, giving the thallus a dimpled appearance. In exceptional members such as Riccia caroliniana of Northern Australia and Riccia sahyadrica of Western Ghats, the photosynthetic region is confined to the lower half of the thallus.
