MCQs on Algae Algae Products made from algae are the natural solutions to the energy, foods, economic, and climate challenges facing our whole world today. Algae have the power to simultaneously puts fuels in our vehicles and recycle CO2, provides nutrition for animals and people and create jobs for millions of indian Algae? Naturally. What … Read more
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The cells taking part in reproduction undergo changes to form typical structures which germinate to give rise to a new plant. Asexual reproduction is characterised by chromnosome number which remains the same as that of the parent cells, meiosis being not involved.
The most common method of vegetative reproduction is fragmentation. The thallus breaks into pieces and each piece is capable of regeneration. In blue- green algae such pieces of trichomes are called hormogonia.
The most common methods of reproduction are vegetative and sexual. Asexual reproduction is occurs only rarely.
The thallus is an unbranched and uniseriate filament where cells are arranged in a single row… All the cells of a filament are similar. In some species holdfast is present (e.g.. S. fluviatilis) The cells are mostly rectangular and longer than broad. The cell wall is two layered;
Spirogyra is represented by about 300 species. It is a freshwater alga found free floating on the surface of stagnant pools, ponds, ditches, etc. A few species are also known to grow attached to the substratum
Different proposed Many algologists have classifications of algae. These are based on different characters. However, the algal pigments have still remained the major basis of algal classification.
Cephaleuros virescens, a green alga, is a parasite and causes red rust of tea in some tea growing parts of India, especially Assam. It is known to cause extensive damage to this crop.
Algae grow abundantly in water reservoirs where and (especially nitrates of nutrients and excess sulphates) are available to them. Such an algal growth floats on the water surface and looks like foam or soap lather.
The sewage disposal is an aerobic process and production of oxygen from algal photosynthesis helps it. Algae like Chlorella, Scenede smus, Pediastrum, Oscillatoria
Algae has always been useful for conducting physiological and genetic experiments since these can be easily grown and manipulated.
Blue-green algae like Aulosira and Anabaena, and green algae like Chara and Nitella eliminate mosquito larvae from ponds and pools in which they grow.
Chlorella (green alga) yields antibiotiC an chlorellin which is useful against both gram positive and gram negative bacteria. Besides this, Laminaria, Ascophyllum, Rhododmela, etc., also have antibiotic properties.
Of north India could be Saline Usar reclaimed by growing blue green algae, like Nostoc, Anabaena, Seytonema, etc, The algae increase the mineral content of the soil and thus the crop yield.
Blue-green algae (Cyanophyceae), viz., Aulosira, Anabaena, Nostoc, etc., fix elemental nitrogen and thus increase the soil fertility. These algae have special cells called heterocysts which are the sites for nitrogen fixation. P. K. De (1939) was the first to demonstrate
In France, Iceland, Scotland and Norway, members of Phaeophyceae (brown algae) like Fucus Macrocystis, Sargassum, etc., are used as manure. Many useful inorganic minerals are obtained from them.
These are obtained from members of Rhodophyceae, collectively called agarophytes e.g., Gelidium, Gracilaria, etc. Agar is a colloidal or jelly-like substance used for culturing bacteria and various other microorganisms. It is also useful in the preparation of medicines.