Which one of the following would increase population density after certain time?
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → Natality and immigration
Option (4) Natality and immigration — Correct. Population density rises by natality (births) and immigration (individuals of the same species coming in), and falls by mortality and emigration. So natality and immigration increase it.
Note: A similar question was also asked in CUET (UG) 2023 on 05-06-2023 (Slot 2).
NCERT Extract:
Population Growth – “The size of a population for any species is not a static parameter. It keeps changing with time, depending on various factors including food availability, predation pressure and adverse weather. In fact, it is these changes in population density that give us some idea of what is happening to the population – whether it is flourishing or declining. Whatever might be the ultimate reasons, the density of a population in a given habitat during a given period, fluctuates due to changes in four basic processes, two of which (natality and immigration) contribute to an increase in population density and two (mortality and emigration) to a decrease.”