KINGDOM PLANTAE: All multicellular green plants are part of kingdom plantae. Their cell wall is madeup of cellulose. Mostly these organisms are photosynthetic but few insect eater plants are parasitic in nature. Plants reproduce through asexual vegetative propogation and sexual method. Plants are either bisexual or unisexual with separate male and female. Algae, bryophytes, pteridophytes,gymnosperm and angiosperm are the main groups present in kingdom plant.

KINGDOM ANIMALIA: These organisms are heterotrophic multicellular eukaryotic without thick cell wall. They depends on plants for nutrition. They have digestive system, circulatory system and well defined sensory and neuromotor mechanism. These organisms have a definitive development pattern to acquire defined shape and size in adults. Reproduction in these organism is mostly by sexual mechanism with separate male and female.  

OTHER ORGANISMS: There are organisms which doen’t fall into five kingdoms due to their unique features. These organisms are not placed and placed into their own group separately. These organisms are as follows:

1. Virus: These are non-nucleated and acellular organisms. Virus can be stored for year as particle and they are considered to be false living organism. They depends on host organisms to provide cellular machinery for multiplication. They contains genetic material either as DNA or RNA and protein coat. Post infection, they integrate their genetic material into the host genome to  control the cellular machinery of host. Virus can use bacteria, plant or animal cells as host. They are mostly pathogenic and be responsible for disease in bacteria, plant and animals.

2. Viroids: T.O. Diener discovered these organisms which contains only free RNA. They are smaller than virus. It doesn’t contain protein coat as found in virus.  

3. Lichens: As discussed previously, algae and fungo are associated to give organism known as lichen. In this organism, algae is phycobiont and be responsible for preparing food whereas fungi are absorbing mineral nutrient and water.  The association between both counterpart help each other and this kind of association is known as “symbiont”. Lichen are very sensitive to pollution as they don’t grow in high polluted area.

Taxonomic Categories: Each kingdom is a group of similar organism but these organism are further dividied into different taxonomic categories. Different taxonomic categories are given in Figure 2.2. These catagories are as follows: