These were discovered by Diener. These are auto replicating RNA particles without any protein coat. Like virus they are obligate parasites. They have low molecular weight. They do not infect animals or human beings. Plants are their main target. In order to divide they depend ...

This type of reproduction occurs in plant and animal viruses. For Example, Tobacco Mosaic Virus, Herpes Virus etc. These viruses act chemically. Attachment and Penetration are their main methods of action. In this the viral genome replicates. The replication of viral genome occurs mainly by ...

When arthropod act as a vector it is referred as arbovirus. The size of virus varies from 10nm to 1300x6nm. Their size is not confined and is quite irregular. The shape of virus is not static. It keeps on changing, it may be helical or ...

It is defined as a complex and smallest entity which depends upon another living cell for its survival and divides according to the condition of other cell without growth and division. Most common viral diseases are small pox and polio. It was Pasteur who coined ...

These are multi cellular consumers with most diverse and large number of organisms. There body form is regular with internal organs. They have no cell wall and there is no photosynthesis. They possess muscle cells. Reproduction is sexual with presence of embryo stage. These are ...

It consists of multi cellular eukaryotic plants. Non photosynthetic plants, algae are also included. They have indefinite growth with external organs. Most of them have autotrophic mode of nutrition and are known as producers as their ability to make their own food (photosynthesis). Some plants ...

These are multi cellular decomposers such as yeasts, mushrooms, puff balls, penicillium etc. They are without chlorophyll and produce spores. They have heterotrophic type of nutrition. Their body is filamentous and is referred to mycelium. Filaments or hyphae are present which may be multi cellular ...

It includes all unicellular eukaryotes organisms such as diatom, ciliates, slime moulds, sporozoans etc. They have different types of nutrition. They live in sea and form plankton which may be photosynthetic known as Phytoplankton. In contrast the plankton which are non photosynthetic are known as ...