Test: Biological Classification - 1

Five kingdom classification was proposed by R.H. Whittaker in 1969. The kingdoms identified by him were:
► Monera
► Protista
► Fungi
► Plantae and 
► Animalia.

Cladogram is representation of arranging organism on the basis of their shared similar or derived characters that differ from ancestral character. It is an important tools of taxonomical studies.

Fig: Cladogram

• Monera is a kingdom that contains unicellular organisms with a prokaryotic (is a unicellular organism that lacks a membrane- bound nucleus, mitocondria, or any other membrane- bound organelle.) cell organization, like bacteria.
• They are single- celled organisms with no true nuclear membrane. The taxon Monera was first proposed as a phylum by Ernst Haeckel in 1866. 

Species is the lowest or basic taxonomic category which consists of one or more natural populations of individuals that resemble one another more closely than individuals of other species, interbreed freely, have a distinct genetic set up and are reproductively isolated from others e.g., Panthera Leo (Lion), Mangifera indica (Mango), Solanum tuberosum (Potato).

• Symbiotic association between an alga and a fungus is called Lichens.
• Algae prepare food due to presence of chlorophyll and fungus absorbs nutrients and provide protection to algae.

Kingdom Protista, kingdom Fungi, kingdom Plantae possess nuclear membrane while kingdom Monera do not possess nuclear membrane.

Methanogens are group of obligate anaerobic ancient and primitive bacteria. They are involved in methanogenesis and produce methane gas in ruminant of cattle.

Cell wall of fungi consists of special sugar molecules called chitin. The cell wall of plants are made up of cellulose.

Fungi is important in nutrient cycle and acts as decomposer along with bacteria and minerlisers of the biosphere to regulate recycling of nutrients in the biosphere.

Viruses are acellular, meaning they are biological entities that do not have a cellular structure. Some of the most complex virion structures are observed in bacteriophages, viruses that infect the simplest living organisms, bacteria.

In Whittaker’s five kingdom of classification, kingdom protista, kingdom fungi, kingdom plantae and kingdom animalia are eukaryotic organisms. The kingdom monera includes prokaryotic organisms.

Prokaryotes differ from Eukaryotes in absence of nuclear membrane and membrane bounded organelles like mitochondria,Golgi bodies etc.

Euglena is a special type of organism as it shows mixotrophic mode of nutrition ie in presence of sunlight it is phototrophic and in absence of sunlight it derive nutrition by saprophytic modes. In presence of sunlight it is autotrophic.

In fungus, the food reserve is glycogen and fat. Different fungi contain different kinds of reserve food materials depending upon habitat and body structure of fungus.

Viroids are smaller than viruses and cause potato spindle tuber disease. It was found to be a free RNA; it lacks the protein coat that is found in viruses, hence the name viroid. The RNA of the viroid was of low molecular weight.

Kingdom Protista has brought together Chlamydomonas, Chlorella which were earlier placed in Algae (within plants and both having cell walls) with Paramoecium and Amoeba which were earlier placed in the animal kingdom which lack cell wall.

Cytotaxonomy is the classification on the basis of comparative cytological studies, number of chromosomes and behavior of chromosomes.

Azotobacter is the gram-negative free-living soil microbes which are found in alkaline to the neutral soils. They are important in the nitrogen fixation process. They have a complete range of enzymes required for nitrogen fixation. They are non-photosynthetic and few of the Azotobacter species live in association with plants.

The correct option is Option B.

The Agaricomycetes are a class of fungi in the division Basidiomycota. The taxon is roughly identical to that defined for the Homobasidiomycetes by Hibbett & Thorn, with the inclusion of Auriculariales and Sebacinales.

• A virus is an infectious agent that typically consists of the nucleic acid molecule in a protein coat. Nucleic acid could be either DNA or RNA.
• In our environment, virus exists in two states - extracellular and intracellular.
• Extracellular before it invades the host cell and once the virus invades a host cell, it is in an intracellular state.
• Antibiotics can't kill viruses because viruses have a different structure and replicate in a different way.
• Antibiotics work by targeting the growth machinery in bacteria (Not viruses).

Classification given by Bentham and Hooker is Natural System. Monocots were placed after dicots, closely related families were seperated, gymnosperms were placed between dicots and monocots.

Plant cells have a cell wall made up of cellulose and chloroplast that contain chlorophyll for photosynthesis. Animal cell lacks both cell wall and chloroplast.

Asexual reproduction in fungi takes place by conidia, zoospore, sporangiospores, chlamydospore and oidia.
In some fungi, the spores are not formed inside a sporangium. They are born free on the tips of special branches called conidiophores. This spores thus formed are called conidiophore for example in Penicillium.

• Bacterial cells are primitive cells hence, are called as prokaryotic cells. They do not possess membrane-bound organelles as mitochondria, Golgi complex etc.
• The processes which are carried out by such specialised organelles are carried over by plasma membrane of bacteria.
• The plasma membrane is a living membrane that forms the boundary between a cell and its environment. Some invaginations of the plasma membrane are called as mesosomes which are involved in the process of respiration and called as a respiratory centre.

• Viral infection occurs when an organism's body is invaded by pathogenic viruses, and infectious virus particles (virions) attach to and enter susceptible cells. 
• The viral disease includes common cold, flu and warts. They also cause severe illnesses such as HIV/AIDS, smallpox, and Ebola. 
• Viruses are like hijackers. They invade living, normal cells and use those cells to multiply and produce other viruses like themselves. Hence, Tuberculosis is not a viral disease.

So, the correct answer is 'Tuberculosis'.