Question

Which figure relates the trend of population growth of India from 1951-2001?
A)

B)

C)

D)

Answer 1

Hint: Scientific study of human population is called demography. The total number of individuals of a species present in a particular area at a given time together form a population. The population has specific characters different from the character of individuals. Populations evolve different strategies to maximize their reproductive fitness.

Complete answer:
(1) Population density: It is measured as the total number of individuals present in unit area or unit volume. The size of a population for any species constantly changes depending on various factors including food availability, predation pressure and weather change.
(2) Birth rate/ Fertility/ Natality: Birth rate is defined as total number of birth in a population with respect to total number of individuals of the population in a year. Birth rate is represented as per capita birth rate.
(3) Death rate: Death rate is defined as total number of deaths in a population with respect to total number of individuals of the population in a year.
(4) Growth rate: Growth rate refers to the percentage change of a specific variable within a specific time period. Intrinsic growth rate $(r) = b - d$.
Natality, Mortality, Immigration and emigration are the other basic processes responsible for fluctuation in population size under normal conditions.

Time of 1951-61: is named as population blast period. High birth rate, low death rate and better wellbeing facilities were explanations behind this.
Time of 1961-71: growth rate of population was 24.8%
Time of 1971-81: growth rate of population was 25%
Time of 1981-91: growth rate of population was 25.3%
Time of 1991-2001: growth rate of population was 26.9%.

Population of India expanded to 102.70 crore in 2001. The main reason behind this tremendous population over the most recent 50 years was a fall in death rate, progressed health facilities and no fall in birth rate. Subsequently, the concave shaped growth curve is obtained.

So, the right answer is option (C).

Note:
Natality and mortality are the most important factors influencing population size then other two factors that is immigration and emigration.
Some other characters of population are as Age and Sex structures. The Age structure of a given population refers to the proportion of individuals of different ages is an important aspect because many functional aspects of individuals are related to age. Age structure of the population can be depicted in the form of a pyramid diagram.