Observe the given figure representing different age pyramids for human population and answer the following question.
Identify the correct statements from the following:
(A) Population size can be estimated indirectly
(B) The only measure to know the population size is to count the number of individuals
(C) Tiger census is often based on the number of animals or humans killed
(D) Tiger census is often based on pug marks and fecal pellets
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → (A) and (D) only
(A) Population size can be estimated indirectly — True. Counting every individual is not always possible.
(B) The only measure to know the population size is to count the number of individuals — False. Indirect measures such as pug marks are used.
(C) Tiger census is often based on the number of animals or humans killed — False. The census uses indirect signs of living tigers, not the number of kills.
(D) Tiger census is often based on pug marks and fecal pellets — True.
NCERT Extract:
Population Attributes – “… Sometimes, for certain ecological investigations, there is no need to know the absolute population densities; relative densities serve the purpose equally well. For instance, the number of fish caught per trap is good enough measure of its total population density in the lake. We are mostly obliged to estimate population sizes indirectly, without actually counting them or seeing them. The tiger census in our national parks and tiger reserves is often based on pug marks and fecal pellets.”