Share Answer A taxonomic hierarchy is the sequence of arrangement of taxonomic categories in a descending order during the classification of an organism. There are seven obligate categories kingdom, division, class, order, family, genus and species. Species is the lowest category while kingdom is the highest category. <br />The number of common characters is maximum in case of organisms placed in the lowest category. Number of common characters decreases with the rise in category. Species are the smallest group of individuals which can be recognized by ordinary methods as groups and which arc consistently and persistently different from other groups because their characters are less general.

Share Answer Cauliflower mosaic virus contain ds DNA. It is circular and shows semidiscontinuous type of replication.

Share Answer Whittakers system is based on the following three criteria <br /> complexity of cell structure. <br /> complexity of the body organization. <br /> mode of nutrition. <br />On the basis of these criteria, Whittaker divided organisms into five kingdoms. These five kingdoms are monera, protista, algae, fungi and animalia. In the five kingdom classification all, prokaryotes have been placed in kingdom monera, all unicellular eukaryotes in kingdom protista, fungi (except slime moulds and water moulds) in their separate kingdom while kingdom plantae and kingdom animalia have been retained for multicellular, autotrophic and multicellular holozoic organisms respectively.

Share Answer Biosystematics is the study of identification, nomenclature classification and relationships amongst living beings. In other words, it is the study of diversity of organisms, their comparative and evolutionary relationships based on comparative anatomy, ecology, physiology, biochemistry and other fields.

Share Answer The kingdom monera includes all prokaryotes. They are basically unicellular but can be mycelial, colonial and filamentous. They contain peptidogycan in cell wall. Naked circular DNA coiled to form nucleoid without association with histones, ribosomes 70s, thylakoids present in photoautotrophs but other membrane bound 1 organelles are absent. Nutrition is of various types parasitic, chemoautotrophic, photoautotrophic and saprobic. <br />Some monerans have the ability to fix nitrogen. Due to presence of these characters in arehaea and nitrogen- fixing organisms they are placed under monera. <br />All others fungi, plantae, protists and animalia are eukaryotic.

Share Answer Phenetic classification is a type of numerical taxonomy. In this type of classification the organisms are arranged according to overall similarity of existing organisms based on available characters. <br /> It is also called adansonian taxonomy because the same was first attempted by Adanson (1763), of course on the basis of external traits only. Numerical taxonomy evolved around 1950. <br /> It has received impetus with the availability of calculating machines and computers. In numerical taxonomy as many characters as possible are employed for evaluating degree of similarity and difference. All characteristics used in analysis are given equal weightage and importance. <br /> A proper selection of characters, their organisation and analysis in the light of current knowledge is key to success of this method. A lot of subjectivity can creep in depending upon the judgement of the biosystematist. No weightage is given to the quantity of the character present.

Share Answer Species is a natural population or group of natural populations of individuals which are genetically distinct and reproductively isolated with similar essential morphological traits. Species is also a genetically closed system because its members do not interbreed with members of other species. Species is lowest or basic taxonomic category, e.g., mango {Mangifera indica), potato (Solanum tuberosum), lion (Panthera Leo). <br /> Here indica, tuberosum, Leo are species of genera Mangifera, Solatium and Pantera respectively. All other taxonomic categories are defined and described in relation to species. For example, a genus is a group of species and a subspecies or a variety is a part of species. New species originate from already existing species. Species is considered basic unit of taxonomy since in the greater majority of cases we do not have intraspecific names.

Share Answer Viruses contain a protein coat that encloses a single type of nucleic acid, either RNA or DNA. They multiply only inside the living host cells and for this they take over the machinery of the host cell. They lack cell division and enzymes for protein synthesis. They do not have cell 01 ganclles like mitochondria, Golgi complex, lysosomes ribosomes etc. so they cannot live or reproduce separately.

Share Answer TMV is rod shaped measuring 300 20 nm. It is made of RNA and proteins.

Share Answer Viruses contain a protein coat known as capsid which encloses a single type of nucleic acid, either RNA or DNA. They do not have enzymes for protein synthesis. They multiply only inside the living host cell and for multiplication they take over the machinery of the host cell. Thus viruses are obligatory intercellular parasites.