Question

The difference between birth rate and death rate is termed as
(a) life rate
(b) survival rate
(c) birth ratio
(d) none of these

Answer 1

Hint: Population is described on the basis of several characteristics which include birth rate, death rate, population growth, population size and density. The population has a specific character different from the character of an individual.

Complete answer.
Birth rate, also called Natality, is the total number of births in a population with respect to the total number of individuals of the population in a year. It is expressed as:
Per capita birth rate = Total number of birth/ Initial population
Two types of Natality can be distinguished, Absolute or maximum Natality which includes the maximum production of new individuals under ideal conditions. Ecological Natality refers to an increase in populations prevailing conditions.
Death rate, also called Mortality rate, is defined as the total number of deaths in a population with respect to the total number of individuals in a year. It is expressed as:
Per capita death rate = Total number of death/ Initial population
Two types of Mortality can be distinguished, Minimum mortality which represents the theoretical minimum loss under natural conditions. Actual or realized mortality is the actual loss of individuals in a population under environmental conditions.
Thus, the difference between birth rate and death rate is termed as a survival rate. Survival rate explains the exact difference of people who still survive for a given period of time starting from birth till they are diagnosed by any illness, which would further lead to death. Survival rate emphasizes the period of survival of a particular population.

So, the correct answer is ‘survival rate’.

Note:
Birth rate, death rate are the basic processes which are responsible for fluctuation in population under normal conditions.
These two are also considered to be the important factor for influencing population size and density.
There is a birth-death ratio called the vital index in a given population during a given time.