Tag: bryophyta

Riccia is a liverwort (Hepaticae), which grows predominantly in wet terrestrial habitats and are free-floating or submerged aquatic.

Sperm of mosses are biflagellated, ie., it has two flagella that aid in propulsion. Since sperm must swim to the archegonium, fertilisation cannot occur without water.

The only aquatic bryophyte is Riccia fluitans, or crystalwort, which  is a floating bladderwort. Sphagnum is also called as peat moss or bog moss. The sporophyte is completely surrounded by a tough protective covering called the calyptra. The new adult gametophytes grow from a tiny bud that develops on the protonema.

In Marchantia particularly it appears that only some of the spore mother cells (Sporocytes) which are diploid remain diploid and undergo change to form elaters. 
The other ( Majority of them ) undergo meiosis to form haploid spores. 
So in Marchantia the elaters are diploid. 

Merosity is a term that refers to the number of component parts in each whorl of the plant basically the flowers which include, sepals, petals, and stamens. the trimerous condition is a characteristic feature of monocots and is found in Liliaceae.
Walking fern refers to the species of Asplenium. Adiantum caudatum is walking maidenhair.
The vascular system of gymnosperms is made up of xylem with tracheids, parenchyma, and rays. vessels are however present in Gnetum, Ephedra having evolved from pitted tracheids. The phloem is made up of sieve cells but companion cells are absent.
Riccia and Marchantia are liverworts a belong to  the order Marchantiales. Thus, the correct answer is option E.

Mosses and liverworts occur in a variety of habitats. These non-vascular plants (bryophytes) lack well developed water conducting tissue and tend to be most abundant in moist areas, such as the splash zones of a waterfalls, or in the higher elevation forests that are frequently enveloped in fog.
Mosses and liverworts contain photosynthetic pigments and, like more advanced plants, produce their own food from sunlight. Mosses typically have small leaves arranged in a whorl around a short stem. Liverworts are closely related to mosses, but can usually be recognized by their larger flattened leaves that grow in two rows.

A prothallium, or prothallus is usually the gametophyte stage in the life of a fern or other pteridophyte. Occasionally, the term is also used to describe the young gametophyte of a liverwort or peat moss as well. An archegonium is a multicellular structure or organ of the gametophyte phase of certain plants, producing and containing the ovum or female gamete. The corresponding male organ is called as the antheridium. An antheridium or antheridia is a haploid structure or organ producing and containing male gametes (called as antherozoids or sperm). It is present in the gametophyte phase of cryptogams like bryophytes and ferns, and also in the primitive vascular psilotophyta. Rhizoid is a filamentous outgrowth or root hair on the underside of the thallus in some lower plants, especially mosses and liverworts, serving both to anchor the plant and (in terrestrial forms) to conduct water. 

Bryophytes are dependent on water because the sperms can easily reach up to the egg in the archegonium. Thus, they are called as amphibians of the plant kingdom.