The hierarchy is an organizational form in which some components regulate the activity of other components. They are of different types and can be physical, biological or ecological.
The physical hierarchy includes the smallest structural units. They can be living or non living. It includes neutron, proton and electrons. They all compose an atom. The atoms combine to form molecules. The complex compounds are formed of molecules. They can later on form organelles. The organelles constitute a cell.
The biological hierarchy starts from cell. The cells form tissues which form organs. Later on organ system is formed from it. The organ system forms organism.
The ecological hierarchy includes its smallest unit known as organism. It forms species, population and ecosystems. The ecosystems form the biosphere.
The organism is a unique living being which can be single celled or multi celled. It carries out all the life processes of body without being dependent on others. It shows growth, movement, self repair and regulation. It is composed of organ systems, organs, tissues and cells. These structures cannot survive if they are isolated. It can adapt to the environment and can interact with it. They are distinct in their appearance that’s why they have a unique identity. It helps them to get easily recognized and can be counted. Some organisms live alone and some of them are dependent on other organisms. The already existed individuals give rise to new individuals. They have different modes of reproduction. It can be sexual, asexual and vegetative. The off springs are very similar to parents. They have a definite life span and they degenerate after that which is also known as a death. They show development, maturity, ageing etc. The characters are transferred from the parents to off springs.
The population includes the group of individuals of same type which occur in the particular area at that particular point of time. They are not temporary. There can be localized geographically groups too. Some may occur in forests, ponds and localities. The local population is formed of different populations of the same organism. This member of population can inter breed. This can be adapted genetically to the environment and can be known as ecotype.
The species is formed by the population of same kind of organisms. For example all the humans belong to species Homo sapiens.
The biotic community is formed by the species that live in a particular area and interact with one another. They have a higher grouping than populations and are collection of populations which have different organisms. They are not isolated and show different types of interactions. The ecosystem consists of community of living organisms. It is a part of nature. It also includes the physical environment and its interaction with the organisms. The biosphere is the inhabitant part of earth which has a collection of ecosystems.
