Plant Kingdom Test - 29

The Phaeophyceae or brown algae are a large group of marine multicellular algae. They play an important role in marine environments. Both, Laminaria and Fucus are the genera of Phaeophyceae. Thus, the correct answer is option C.

The reserve food of brown algae is laminarin. The molecule laminarin (also known as laminaran) is a storage glucan (a polysaccharide of glucose) found in brown algae. It is used as a carbohydrate food reserve in the same way, that chrysolaminarin is used by phytoplankton, especially in diatoms. Thus, the correct answer is option C.

More than 95% of moss species belong to the Bryopsida. The most important characteristic of the Bryopsida is the architecture of the ring of teeth (peristome) surrounding the mouth of the sporophyte capsule. Bryopsida are the only mosses, that have an arthrodontous peristome, i.e., a peristome in which the teeth are structured by articulated cell wall remnants.

Peat is a dead form of Sphagnum moss. The lakes where sphagnum grows are called as Sphagnum bogs. These are well known to produce peat in acidic water.

Solution:

Correct answer is option A.
Explanation for correct option:

• Pteridophytes are vascular plants, i.e., they have tissues specialized in the conduction of water and nutrients. 
• Bryophytes are nonvascular plants. 
• In pteridophytes, transportation is done through vessels, and in bryophytes, that transportation occurs by diffusion. 

Dawsonia is a classification of mosses. This genus is a member of the Polytrichaceae family. Dawsonia plants are commonly known to grow taller and have thicker leaves than other common mosses.

Sphagnum is one of the most important plant genera in the world. Sphagnum is one of the few bryophyte genera able to dominate an ecosystem. A healing ointment prepared by Sphagnum leaves mixed with grease is used in the treatment of cuts and wounds. The decoction prepared by boiling dried Sphagnum in water, is used in the treatment of acute haemorrhage. This decoction is used to cure diseases of eyes. The lakes where sphagnum grows are called as Sphagnum bogs. These are well known to produce peat in acidic water. The bog water is antiseptic and has astringent properties. Sphagnum exhibit strong antibacterial properties against Gaffkeya tetragena and Staphylococcus aureus. Sphagnum peat is suitable for production of low and intermediate BTU gas as well as hydrogen , ethylene , natural gas , methanol and gasoline. Sphagnum is used as an effective filtering and absorption agent for the treatment of waste water and effluent of factories with acid and toxic discharge consisting of heavy metals particularly Ag, Pb, Cu , Hg, Fe , Sb and organic substances like detergents, dyes, microorganisms and soils.

Anthoceros species are host to species of Nostoc, a symbiotic relationship in which Nostoc provides nitrogen to its host through cells known as heterocysts, and which are able to carry out photosynthesis. Anthoceros is a genus of hornworts in the family Anthocerotaceae. The genus is global in its distribution. Its name means 'flower horn'.

Cosmarium is a non-motile, freshwater member of division Chlorophyta. Cosmarium is a relatively large unicell characterized by a constriction in the middle of the cell which divides it into two symmetrical halves or semicells. A single haploid nucleus occupies the isthmus. Each semicell is partly filled by a large green chloroplast containing two pyrenoids composed of proteinaceous material. Surrounding the pryenoid are numerous starch granules. A large portion of the protoplast of each semicell is occupied by a clear vacuole. The cell wall is relatively rigid and composed of cellulose, a polysaccharide found in the cell walls of most members of the division Chlorophyta and all members of the more highly evolved plant groups. But there are no locomotive organelles present in the cell hence making it a non motile cell.

Elaters are structures present in plants. They are generally present to facilitate spore dispersal (liverworts) but are absent in mosses and spore dispersal is controlled by the peristome.