12 Biology Organisms and Populations - Set No : 9 Question No :1
Question No : 1
Age
pyramid  and  indicates |
| a) | A-Expanding population, B-Stable population, C-Declining population | b) | A-Expanding population, B-Declining population, C-Stable population |
| c) | A-Stable population, B-Declining population, C-Expanding population | d) | A-Declining population, B-Stable population, C-Expanding population |
Answer No : 1
| (a)A-Expanding, B-Stable, C-Declining.Age pyramid Graphic representation of different age groups found in a population with pre-reproductive group at the base. Reproductive ones in the middle and post-reproductive group at the top is called age pyramid.Age pyramid have three kinds(i) Triangular Age Pyramid The number of pre-reproductive is very large. Number of reproductive individual is moderate and post-reproductive are fewer. Population size is growing(ii) Bell-shaped Age Pyramid The number of prereproductive and reproductive individuals is almost equal. Post-reproductive individuals are comparatively fewer. Population size is stable(iii) Urn-shaped Age Pyramid Proportion of reproductive age group is higher than the individuals in pre-reproductive age group. Number of post-reproductive individuals is also sizable. It is declining population with negative growth |