Category: BOTANY(I Year VIDEO)

Oscillatoria is found in rain water of pools, ponds, rivers, streams, lakes and in polluted water. Some of the species of Oscillatoria are plank tonic, some are found in hot water springs e.g O. terebriformis, and some species of Oscillatoria are found in saline waters. e.g. O. limosa. Oscillatoria in unbranched and filamentous. The trichome consists of cells which are arranged in uniseriate fashion. Oscillatoria species show Gaidukov phenomenon. Species of Oscillatoria can assume different shades when they are provided with light of different wavelengths. The trichome shows gliding movement as well as oscilllatory movement. During vegetative growth of the trichome, some cells of the trichome are filled with mucilage and become dead. These cells are called necridia. Thus Oscillatoria reproduces by the formation of Hormogonia and by fragmentation.

Cycas is an evergreen , palm like small tree. It grows in xerophytic habitats. The sporophytic plant body of Cycas is differentiated into roots, stem and leaves. The roots are of two types : Normal tap roots and coralloid roots. The leaves are also of two types i.e. dimorphic . The assimilatory leaves or foliage leaves and Scale leaves . The asexual reproduction takes place by the formation of sporangia and spores . The sporangia are arranged on the lower side of the microsporophyll in definite groups called sori. Sexual reproduction occurs by the formation of antheridia and archegonia.

Ectocarpus is a marine alga. The thallus is heterotrichous. It consists of a prostrate rhizoidal system and an erect branched system . The main pigment is xanthophyll. The cytoplasm contains polyphenol containing vacuoles called physodes. The asexual reproduction occurs by the formation of zoospores in two types of sporangia called unilocular sporangia and plurilocular sporangia. The sexual reproduction occurs by isogamy , morphological anisogamy and physiological anisogamy. In physiological anisogamy the male gametes are more active than the female gamete. Ectocarpus is a brown alga and shows Isomorphic alternation of generation.

Peziza is called as cup fungus. Peziza is a saprophytic and coprophilous fungus. The mycelium is profusely branched, uninucelate and cup shaped. The asexual reproduction occurs by means of conidia and chlamydophores and conidia. The sexual reproduction occurs by somatogamous copulation. The apothecium is the fruiting body. It is sessile and sub- sessile.

This is a part of lecture presented by Dr. Ruby Singh Parmar,(Head Of The Department,Science),Biyani girls college. This video is about algae which belongs to family chara.This algae is commonly called as “stone wort” because it occurs in areas which are rich in limestone.In this video morphology anatomy and reproduction of chara discussed.