In a pond there were 20 lotus plants last year and through reproduction 8 new plants are added taking the current population to 28. Birth rate of lotus plant in pond is:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → 0.4 lotus per year
Birth rate is a population attribute. It is the number of births during a given period per member of the population, not the total number of births.
\( \displaystyle \text{Birth rate} = \frac{\text{new individuals added}}{\text{population at the start}} \)
\( \displaystyle \text{Birth rate} = \frac{8}{20} = 0.4 \)
So the birth rate is 0.4 offspring per lotus plant per year. The value 8 is only the number of new plants, not the rate.
Note: A similar question was also asked in CUET (UG) 2025 on 16-05-2025 (Slot 1) and on 15-05-2025 (Slot 1).
NCERT Extract:
Population Attributes – …
