Question

If a pond with an average population of 20 lotus plants experiences 8 new plants through reproduction in one year, what is the natality rate?

Options

• 0.4 offspring per lotus per year

• 0.25 offspring per lotus per year

• 8 offspring per lotus per year

• 2.5 offspring per lotus per year

Answer 1

Using the natality formula:

\[
\begin{aligned}
b &= \frac{\text{Number of births per unit time}}{\text{Average population}} \\[4pt]
b &= \frac{8}{20} = 0.4
\end{aligned}
\] 

0.4 offspring per lotus per year. This represents the birth rate relative to the population size.