Class 12 NEET Biology Organisms and Populations

(a) : The characteristics of biological community are dominance, species diversity, trophic organisation, stratification, dynamism and stability. Organisms are not uniformly distributed throughout a community. They usually occur in definite zones. This spatial arrangement of populations is called stratification. Structurally a community may be divided horizontally into sub communities. This horizontal division constitutes the zonation in the community. Natality, mortality, age structure and sex ratio are the basic characteristics of a population.