Tag: botany

Pteridophytes are vascular plants which have leaves (known as fronds), roots and sometimes true stems, and tree ferns have full trunks. For example, ferns, horsetails and clubmosses. Fronds in the largest species of ferns can reach some six meters in length. Many ferns from tropical rain forests are epiphytes, which means they only grow on other plant species. Their water comes from the damp air or from rainfall running down branches and tree trunks. There are also some purely aquatic ferns such as water fern or water velvet (Salvinia molesta) and mosquito ferns (Azolla species). 

Pteridophytes are seedless ferns. They use sexual and asexual mode of reproduction. Spores produced by pteridophytes that help in sexual reproduction. These spores are carried long distances for pollination by abiotic factors like wind, water, etc. Once the spore reaches its destination, it releases the male gametes into the female reproductive system and merges with the female gamete. After successful divisions, it germinates to become prothallus, i.e, the young ones of pteridophytes. So, the correct answer is option B.

Pteridophyta is the only division of sub-kingdom cryptogamae that can reproduce both, sexually by formation of spores as well as sexually by formation of gametes.

Pteridophyta are multicellular, autotrophic plants, they can reproduce asexually as well as sexually. They reproduce asexually by formation of spores and sexually by the formation of gametes.

Heterospory is considered a crucial evolutionary step toward the seed habit, as it leads to the retention of the megaspore and the development of the female gametophyte within the parent plant.

Pteridophytes are called vascular cryptogams because they contain vascular tissues (xylem and phloem) but reproduce via spores rather than seeds.

Equisetum is a genus of Pteridophyta division. They are called as cryptogam. Vascular cryptogamic plants are those plants which have vascular system and do not have seeds. Equisetum is a vascular plant bearing hidden seeds.

Fern stems are often called rhizomes, but this term refers to those with a long-creeping or climbing habit. If the stem is short and compact and radially symmetric, either erect, prostrate or ascending then it is called a caudex or rootstock. In some cases, the caudex is erect and tree-like with an apical radial tuft of leaves in which case it is often called a trunk. The rhizomes of ferns are very rarely naked and usually have some form of covering, especially on their growing tips, to provide protection from the extremes of temperature, desiccation, predation and physical abrasion. The rhizome have sieve tubes but there are no vessels.