MHT-CET : Biology Entrance Exam

### MHT - CET : Biology - Human Population Know More

Population Growth Curves
The two main types of population growth curves are:

1. S-shaped:
S-shaped growth curve is seen occurs when food supply ceases and growth becomes stationary. It is applicable to bacteria, yeast cells, plants and animals.

2. J-shaped:
J-shaped growth curve is seen occurs when food supply ceases and mass starvation leads to deaths.
J-shaped curve is applicable to human population in the absence of environmental resistance.

Causes of Population Explosion in Human History

 Cause 1. First population explosion Change in culture and environment 2. Second population explosion (6,000 years ago) Agriculture and farming 3. Third population explosion ·  Decrease in death rate ·  Industrial revolution ·  Modern medical facilities

Test Tube Baby
Test tube baby is produced when the ovum is fertilised outside (in vitro fertilisation) but development of the foetus takes place inside the uterus.
Durga is the name of the first test tube baby born in
India (Kolkata).

Density of a Population
Density refers to the total number of individuals in a population per unit area at a specific time.
The density of a population is closely related to the size of the organism.
Smaller the size of an organism, greater is the density of organisms and larger the size of an organism, lesser is the density of organisms.

Calculation of Density
The density of a population is calculated with the help of the formula given below:

D =
n/a

D is the density of the population
n is the total number of individuals in the population
a is the area in square kilometres.
The density of population in an area is determined by dividing the total number of people living in an area by the area of land in which they live.

According to the Census of 1991, the density of human population in
India was 267 per square kilometre.

Population Dynamics
Population is an assemblage of individuals of the same species occupying a particular locality at a given time.
The change in the number and composition of a population influenced by one or more factors at a given place at any given time is known as population dynamics.
An increase in the number and size of the population is termed as positive population dynamics.
A decrease in the number and size of the population is termed as negative population dynamics.

• The present rate of growth of human population is about 2% per annum. In developing countries it is 2.5% per annum.
• Japan is the most thickly populated country of the world.
• Australia is the most thinly populated country.
• Kerala is the most thickly populated state of India.

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