<prompt> Population explosion is defined as population growth rate of more than___ per year.21.751.81.5  <response>: Ans. a 2.0 Ref. Park PSM 22ndpg. 443Relation between growth rate and population:RatingAnnual rate of growth Number of years required for the population to double in sizeStationary populationNo growth Slow growthLess than 0.5More than 139Moderate growth0.5 to 1.0139-70Rapid growth1.0 to 1.570-47Very rapid growth1.5 to 2.047-35Explosive growth2.0 to 2.535-28Explosive growth2.5 to 3.028-23 