Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
NEETZoologyOrganisms and Populations

A human population exhibits an urn-shaped age pyramid. If this population experiences zero immigration and zero emigration, which of the following relationships must be true regarding its demographic factors?

Options

  1. ANatality is less than Mortality
  2. BNatality is greater than Mortality
  3. CNatality is equal to Mortality
  4. DNatality plus Immigration is equal to Mortality plus Emigration

Correct answer

A. Natality is less than Mortality

Step-by-step solution

An urn-shaped age pyramid has a narrower base (fewer pre-reproductive individuals) compared to the reproductive age group, which indicates a declining population. The equation for population density change is N_ t+1 = N_ t + [(B + I) - (D + E)] . Given that immigration ( I ) and emigration ( E ) are zero, the equation simplifies to N_ t+1 = N_ t + (B - D) . For a declining population, N_ t+1 must be less than N_ t , which means (B - D) must be negative. Therefore, natality ( B ) must be strictly less than mortality

Practice Organisms and Populations on Quantrex Academy →

More from Organisms and Populations

Match List-I with List-II . List-I List-II A. Both species are harmed I. Predation B. One species is harmed and the other is benefited II. Mutualism C. Both species are benefited I 2026Choose the correct statements regarding population interactions between two species. A. In both parasitism and commensalism, only one species benefits and the other species is harm 2026Which of the following equations depicts Verhulst-Pearl logistic population growth ? 2026Consider a population of 10 million cells. Given the per-capita birth rate of 0.002 (per unit time) and the per-capita death rate of 0.002 (per unit time), the expected number of c 2026Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R . Assertion A : The logistic growth model of populations is considered more re 2026Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R . Assertion A : Abingdon tortoise in Galapagos islands became extinct within a 2026Which one of the following is an appropriate example of 'sexual deceit' ? 2026Who is known as the father of Ecology in India? 2025 Full Organisms and Populations list All NEET PYQs