Identify the correct characteristics of Age-Sex distribution of population by pyramid method.
A. Age-Sex pyramid of Australia is bell-shaped.
B. Age-Sex pyramid of Bangladesh is narrow base and wide top.
C. Age-Sex pyramid of Nigeria is triangular shaped.
D. Age-Sex Pyramid of Japan has narrow base and tapered top.
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → A, C and D only
An age-sex pyramid shows the number of males and females in each age group. Its shape tells how the population is changing.
A. Age-Sex pyramid of Australia is bell-shaped. — Correct. Australia’s pyramid is bell shaped and tapered towards the top. Birth and death rates are almost equal, so the population stays nearly constant.
B. Age-Sex pyramid of Bangladesh is narrow base and wide top. — Incorrect. Bangladesh’s pyramid looks the same as Nigeria’s: a triangle with a wide base. High birth rates give it many young people.
C. Age-Sex pyramid of Nigeria is triangular shaped. — Correct. Nigeria’s pyramid is triangular with a wide base, typical of less developed countries with high birth rates.
D. Age-Sex Pyramid of Japan has narrow base and tapered top. — Correct. Japan’s pyramid has a narrow base and a tapered top, showing low birth and death rates.
Note: This question is taken from the pre-rationalised NCERT book. The latest edition (2026-27) does not have this part. An extract of the pre-rationalised NCERT book is given below for the benefit of students.
Pre-rationalised NCERT: “Expanding Populations … The age-sex pyramid of Nigeria as you can see is a triangular shaped pyramid with a wide base and is typical of less developed countries. These have larger populations in lower age groups due to high birth rates. If you construct the pyramids for Bangladesh and Mexico, it would look the same.”
Fig. 3.1: Expanding Population “Constant Population … Australia’s age-sex pyramid is bell shaped and tapered towards the top. This shows birth and death rates are almost equal leading to a near constant population.”
Fig. 3.2: Constant Population “Declining Populations … The Japan pyramid has a narrow base and a tapered top showing low birth and death rates. The population growth in developed countries is usually zero or negative.”
Fig. 3.3: Declining Population |
