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Organisms and Populations — BIOLOGY STD 12 Science — Question

Bihar BoardEnglish MediumSTD 12 ScienceBIOLOGYOrganisms and Populations5 Marks
Question
Study the 3 representative figures of age pyramid relating to human population given below and answer the following question:

  1. Mention the names given to the 3 kinds of age profiles (i), (ii), and (iii).
  2. Which one of them is ideal for a population and why?
  3. How do such age-profile studies help policy makers get concerned about our growing population and prepare for future planning? (say for example: for the year 2022.)
[Hint. The age profile you would name as stable was prepared on the data available on January 2007].
✓

Answer

  1.  
  1. Expanding.
  2. Stable.
  3. Declining.
  1. The stable pyramid is ideal for a population.

Because :

The number of individuals in the pre-reproductive period is almost equal to those in the reproductive period. As a result, the number of individuals in the reproductive period will be the same in future.

  1. The shape of the pyramids reflect the growth status of the population; any aspect of ecological processes is evaluated in terms of a change in the population size.

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