CBSE · Class 12 · Biology · Organisms and PopulationsA small pond has an initial population density of 20 lotus plants. Due to heavy reproduction and favorable environmental conditions, 8 new plants are added in a span of one year. Calculate the birth rate (per individual per year) of the lotus population in that pond. Show all calculations clearly.

Given Data:

• Initial population density ($N$) at the beginning of the year = $20$ lotus plants
• Number of new offspring added (births, $B$) during the year = $8$ lotus plants
• Time period ($\Delta t$) = $1$ year

Formula:\nBirth rate ($b$) is calculated as the number of births divided by the initial population size over a given time interval:

$$b = \frac{B}{N \times \Delta t}$|

Step-by-Step Calculation:

1. Substitute the given values into the formula: $$b = \frac{8}{20 \times 1}$$
2. Simplify the fraction: $$b = \frac{8}{20}$|
3. Perform the division: $$b = 0.4 \text{ offspring per lotus per year}$|

Final Answer:\nThe birth rate of the lotus population in the pond is 0.4 offspring per individual per year.