1.Living World: Characteristics The earth serves as a home for diverse living organisms. The organisms live in various habitats like forests, mountains, deserts, oceans, freshwater bodies, hot springs, polar regions and almost every place of the earth. Living things possess certain characteristics. 1 Growth Living things grow by increase in mass and increase in number of individuals/cells. In multi cellular organisms in particular, growth occur by cell division or increase in number of cells. Growth occurs continuously throughout life in plants, whereas, in animals, it occurs up to a certain age only. However, growing in certain body parts like nails, hair and replacement of lost cells, occurs throughout the life. In unicellular organisms, growth can be observed under the microscope by simply counting the number of cells via in vitro experiment. Non-living things like mountains, boulders, sand dunes also grow in size, but just by accumulating the material on their external surface.