List the different attributes that a population has and not an individual organism.
( b) What is population density? Explain any three different ways the population density can be measured ,with the help of an example each .

Explanation

Following are the attributes that a population has·but an individual organism does not have: 1. Per capita birth·rate. 2. Per capita death rate.
3. Sex ratio : ,Ratio of number of males to females in a population
Population density 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 fallows:
( 1) Per cent cover or biomass : In an area with 200 parthenium plant and only one banyan tree with -large conopy, the denstiy of banyan tree is small but does not reflect its important role in the community. Here percent cover or biomass is a more meaningful method of assesseing population density.
( 2) Total Number : It involves the counting of organisms in the given area.
( 3) Relative Density :In this method m there is no need to count the organsms individually Example the nubmber of fishes caught per trap gives the measure of total density in a given water body.
( 4) Indirect Assesment: The tiger cenus is based on pug marks and faecal pellets.