A population of snails has an annual per capita birth rate of 0.055 and an annual per capita death rate of 0.015.
Calculate an estimate of the change in population size over one year, for a given starting population of 1,000 individuals. Assume that the population grows exponentially according to the equation dN/dt = r^N.

A) increases by 40 individuals
B) decreases by 15 individuals
C) increases by 400 individuals
D) increases by 55 individuals
E) decreases by 20 individuals

Option A,  increases by 40 individuals

Explanation:

Given,

Annual per capita birth rate

Annual per capita death rate

Net per capita population growth rate

The growth equation of population

     Eq 1

On simplifying we get

Substituting the given values in Eq 1,  we get -

Hence, the population increase by individuals.

Option A is correct

step 1: nitrogen fixation- conversion of atmospheric no₂ into forms useful to plants by lightning, bacteria, and cyanobacteria.

step 2: nitrification-process of converting ammonia to nitrite or nitrate.

step 3: assimilation-plant roots absorb new form of nitrogen.

step 4: ammonification-conversion of organic nitrogen to ammonia by bacteria involved in decomposition.

step 5: denitrification-bacteria turns the decomposed matter back into n₂o, which is released into atmosphere; repeat cycle.