(a)
(b) planning of health / education / transport / infra-structure / finance / food / employment can depend on the age - pyramid analysis of a population / any other relevant point.
Detailed Answer:
(a) Population density : It means number of individuals present per unit area. Population density can be measured by determining the population size. The different methods to study population size are as follows :
(i) Quadrat method : It is a method that involves the use of square of particular dimensions to measure the number of organisms. e.g., The number of parthenium plants in a given area can be measured using the quadrat method.
(ii) Direct observation : It involves the counting of organisms in a given area, e.g., In order to determine the number of bacteria growing in a petridish, their colonies are counted.
(iii) Indirect method : In this method, there is number need to count the organisms individually, e.g., number of fishes caught per trap gives the measure of their total density in a given water body.
(b) Age pyramid for human population can help the policy makers to prepare future planning for-stress of family planning measures, help elderly people to live comfortably, planning more schools, technical institutes with digital facilities for education and more job opportunities for future.
