Life is organised in a hierarchical function. This correct sequence of the level of organisation from simple to complex are  atom, molecule,organelle, cell, tissue, organ,  organ system, organism, population, community,ecosystem  and finally biosphere.
Explanation:
Atom:  An atom is the smallest unit of matter which keeps all of the chemical properties of an element. They consists of  positive or negative charges. A proton is a positively charged  particles which lives in the nucleus( core of the atom) of an atom & have a mass of 1 & charge of 1+.Neutrons also reside in the nucleus of an atom.
Molecule : It  is the smallest unit of element or of compound which have the chemical properties of an element or compound.They are  combination of two or more than two atoms  which are connected together by a strong chemical bond. The four molecules of life are proteins, carbohydrates, lipids and nucleic acids. All these are needed by the organisms for their survival. Without any of these survival of the organism can be difficult.
Organelle: An organelle refers to a chamber within the cell which perform a specialised function. Examples are: Mitochondria, Ribosomes and Endoplasmic reticulum. They are found in eukaryotic cells and absent in prokaryotic cells such as bacteria. Their main function is making energy out of food, processing and packaging of proteins.
Cell : They are also known as " building blocks"of life.It is a structural and functional unit of life. Cell consists of cytoplasm which is packed within a membrane  which consist of many  biomolecules like proteins and nucleic acids. Cells are of two types:Eukaryotic and Prokaryotic. Eukaryotic  contains nucleus whereas prokaryotic don't.Prokaryotes are unicellular whereas eukaryotic can either be multicellular or unicellular.The main functions are replication, growth & metabolism and protein synthesis.There are different types of cells which are Stem cells, Bone cells,Muscle cells, fat cells, skin cells,nerve cells and endothelial cells
Tissue : These are set or layerings of cells that perform specialized functions.Some examples are Muscular, Connective and Nervous tissue.
Organ :An organ is a structural composition of 2 or more than 2 tissues working in order  to perform the tasks which is beyond the scope of an individual tissue type. Heart, liver & stomach are some of the examples of organs in humans.
Organ System: It is a set of organs  which are working together as a system to perform many functions. Each organ system is assigned with a particular job/ task in the body and is composed of certain tissues. The 11 organ systems of the body are integumentary, muscular, skeltal, nervous, circulatory, lymphatic, respiratory, endocrine, urinary, reproductive and digestive. Although each of them has a unique task, each organ system directly or indirectly depends on all the others.
Organism : An organism refers to the creature who  is capable of stimulus reaction, reproduction, growth, development and maintenance of homeostasis.It can be virus, bacteria, fungi, protists or an animal.
Population : It is the count or no. of organisms  of the same species that resides in a particular geographic area in the same time having the capacity to interbreed.There are three types of population pyramids: expansive, constrictive & stationery.
Community : It is an interacting set of various species with a same location. For example: Organisms residing on a dead trees & plants  can be considered as a community. Various species of worms, insects, moles, moss, fungi etc. also resides there and carry out various niches. For instance fungi are saprophytic and helps in the breaking down of dead organic matter.
Ecosystem : An ecosystem is a community of living as well as non living species in a specialized local environment.Components of ecosystem  includes water, air, sunlight, soil, plants, microorganisms, insects and animals. Ecosystem may be agroecosystem, aquatic ecosystem, coral reefs, deserts, forests,littoral zone, marine, rainforests,savanna, steppe, taiga, tundra, human ecosystem  and others.
Biosphere : It is the sum of all the ecosystems. It is defined as the area where we can found about the living organisms and products of their activities.It play a very important role i the maintenance of ecosystems i.e. the life of organisms and the interactions between them. Another function of biosphere is the regulation of climate. Main elements of biosphere are oxygen, nitrogen, hydrogen and carbon.
