Population density increases when
Population density increases when
The correct option is C (B+I) > (D+E)
Population density is the number of individuals of a species per unit area at a given time. If the initial population density at time t is Nt, then the population density at time t+1 can be represented as
Nt+1 = Nt+ [(B+I)-(D+E)]
Where,
B is natality i.e. number of births during a given time period.
I is immigration i.e. number of individuals of the same species that enter a population from elsewhere during a given time period.
D is mortality i.e. number of deaths during a given time period.
E is emigration i.e. number of individuals of the same species that leave a population during a given time period.
Both natality and immigration add individuals to a population and have a positive effect on the population density whereas, mortality and emigration deduct individuals from a population and have a negative effect on it. If the total number of individuals added to a population (B+I) is more than the total number of individuals deducted (D+E), then we can say that the population is growing and the population density increases.
Thus, we can conclude that when,
-
(B+I) > (D+E) - the population density increases
-
(B+I) < (D+E) - the population density decreases
-
(B+I) = (D+E) - the population density remains unchanged
Population density is the number of individuals of a species per unit area at a given time. If the initial population density at time t is Nt, then the population density at time t+1 can be represented as
Nt+1 = Nt+ [(B+I)-(D+E)]
Where,
B is natality i.e. number of births during a given time period.
I is immigration i.e. number of individuals of the same species that enter a population from elsewhere during a given time period.
D is mortality i.e. number of deaths during a given time period.
E is emigration i.e. number of individuals of the same species that leave a population during a given time period.
Both natality and immigration add individuals to a population and have a positive effect on the population density whereas, mortality and emigration deduct individuals from a population and have a negative effect on it. If the total number of individuals added to a population (B+I) is more than the total number of individuals deducted (D+E), then we can say that the population is growing and the population density increases.
Thus, we can conclude that when,
-
(B+I) > (D+E) - the population density increases
-
(B+I) < (D+E) - the population density decreases
-
(B+I) = (D+E) - the population density remains unchanged
