Biology [1 Mark Question Answer]

Immigration refers to the addition of individuals to a population while emigration refers to the decrease in a population due to the outgoing population of individuals.

A census is taken in India every ten years by the government to count the number of people in the country.

Women are operated to prevent the flow of eggs into the oviduct by tubectomy.

Population density is defined as the size of a population in relation to a particular unit area at a given time.

For man, Vasectomy and contraceptive, For woman, Tubectomy and pills.

The popular sign for the Family Planning and Welfare Centres in India is the inverted Red Triangle.

At present human population is checked by disease, death due to old age, wars, epidemics, natural calamities such as earthquakes and floods and also by family planning methods.

The growth rate of population can be negative when the death rate is higher than the birth rate of the population.

The growth rate of population is the difference between birth rate and death rate.

Vasectomy

Mortality

Immigration

Natality

Population dynamics

Population density

Population

Full form of MTP: Medical Termination of Pregnancy.

Castration

Homo sapiens

Growth rate of population

More than 10 million, 1000 million (1 billion) and 6 billion

Population explosion

Sex ratio

Age ratio

Emigration

Contraceptives

Demography

Medical discoveries such as antibiotics and vaccinations have resulted in the decrease of death rate resulting in a corresponding rise in growth rate which leads to an increase in population.

In developed countries both death-rate and birth-rate are low due to better medical facilities and family planning methods.

Intrauterine device (IUD) placed in the uterine passage prevents the implantation of fertilized ovum. This checks pregnancy.

The maximum number of individuals which an environment can support is called the carrying capacity. Available space, water, etc., determine it.

Emigration is the decrease in the population due to the movement of organisms outside an area.

Death rate is defined as the number of individuals eliminated from a population by death in a year per thousand population. It is also called mortality rate.

The estimation of human population by physically counting of individuals per unit area. The census Bureau physically verifies the number of persons living in each house.

The number of offspring produced per unit of population is termed natality.

The number of individuals belonging to different age groups is called age-ratio.

Consequences of ‘population explosion’ in India:

1. Scarcity of food, space and water: Although the population is growing rapidly the living and food, space, production available per person has remained constant.
2. Increase in epidemics a (id diseases as a result of unhygenic and crowded living conditions in cities, towns and villages.
3. Unemployment and poverty will be uncontrollable and may lead to social unrest and lack of educational facilities.
4. Destruction of forests and their fauna and flora so that more land can be brought under cultivation or for human dwellings.
5. Problems of sanitation, cleanliness and clean drinking water for the increasing population.
6. Lack of facilities such as schools, colleges, hospitals, transportation, etc.
7. Non-renewable resources such as coal, oil, water, minerals, etc., will be consumed very quickly.
8. Disturbances in ecological balance due to deforestation and pollution.