151. The concept that “population increases geometrically while food supply increases arithmetically” was given by
Stuart Mill
Charles Darwin
Adam Smith
Thomas Malthus
Answer.4. Thomas Malthus
Explanation:
The concept that “population increases geometrically while food supply increases arithmetically” was given by Thomas Malthus.
Malthus stated that population increased in a geometric progression (ie., 2, 4, 16, 132…) while food production increased in arithmetic progression (ie., 2, 4, 6, 8…). Thus population grew faster than food production and tended to outstrip it in a short time.
152. Population pyramids are useful to
Express the population growth rates
Indicate the birth rates
Indicate the death rates
Express age-sex distribution of a population
Answer.4. Express age-sex distribution of a population
Explanation:
A population pyramid is a way to visualize two variables: age and sex. They are used by demographers, who study populations. A population pyramid is a graph that shows the distribution of ages across a population divided down the center between male and female members of the population.
153. The carrying capacity of a population is determined by
Population growth rate
Natality
Mortality
Limiting resources
Answer.4. Limiting resources
Explanation:
Limiting factors or resources determine carrying capacity. The availability of abiotic factors (such as water, oxygen, and space) and biotic factors (such as food) dictates how many organisms can live in an ecosystem. Carrying capacity is also impacted by the availability of decomposers.
154. HIV is not likely to be transmitted by
Sharing needles for injections
Mosquito bites
Blood transfusion
Breastfeeding
Answer.2. Mosquito bites
Explanation:
HIV is not likely to be transmitted by mosquitoes, ticks, or other insects. Through saliva, tears, or sweat. By hugging, shaking hands, sharing toilets, sharing dishes, or closed-mouth or “social” kissing with someone who has HIV.
155. Today, the world’s number one problem is:
Pollution
Population explosion
Nuclear proliferation
Natural calamities
Answer.2. Population explosion
Explanation:
Today, the world’s number one problem is Population explosion. Population explosion gives rise to a number of social problems. It leads to migration of people from rural areas to the urban areas causing the growth of slum areas. People live in most unhygienic and insanitary conditions.
156. Population explosion has occurred in the last
500 years
300 years
400 years
150 years
Answer.4. 150 years
Explanation:
Population explosion has occurred in the last 150 years. The population explosion first occurred on a small scale and with relatively moderate intensity in Europe and America, more or less between 1750 and 1950.
157. Study of trends in human population growth and prediction of future growth is called
Demography
Psychology
Biography
Kalography
Answer.1. Demography
Explanation:
Demography deals with the study of populations attributes. Population attributes like natality, mortality and age distribution keep on fluctuating and greatly affects the growing population.
Demography examines the size, structure, and movements of populations over space and time. It uses methods from history, economics, anthropology, sociology, and other fields.
158. One of the critical mechanisms by which the environment controls the population of species is
Spread of disease
Removal of excreta
Supply of food
Control on death rate
Answer.4. Control on death rate
Explanation:
the critical mechanism by which the environment controls the population of species is to control the death rate. Environmental catastrophes such as fires, earthquakes, volcanoes, and floods can strongly affect population growth rates via direct mortality and habitat destruction.
159. If the rate of addition of new members increases with respect to the individual loss of the same population, then the graph obtained has
Decline growth
Zero growth
Exponential growth
None of these
Answer.3. Exponential growth
Explanation:
If the rate of addition of new members increases with respect to the individual loss of the same population, then the graph obtained has exponential growth. The exponential phase is the period of the rapid rise in population due to the availability of food and requirements of life in plenty and there is no competition.
160. The number of babies produced per thousand individuals is called
Natality
Mortality
Immigration
Emigration
Answer.1. Natality
Explanation:
The birthrate is the ratio of total live births to the total population in a particular area over a specified period of time; expressed as childbirths per 1000 people (or population) per year.
161. The zero population growth due to equal birth and death rates is called
Fertility rate
Replacement level
Natural increase
Demographic transition
Answer.4. Demographic transition
Explanation:
The zero population growth due to equal birth and death rates is called demographic transition.
Thus, zero population growth occurs when birth and death rates are equal. The birth rate refers to the number of births per 1,000 people per year, while the death rate refers to the number of deaths per 1,000 people per year.
162. Demographic features of developing countries are
High infant mortality, low fertility, young age distribution and uneven population growth
High fertility, high density, high mortality rate and young age distribution
High fertility, falling mortality rate, rapid population growth and young age distribution
High density, high mortality, uneven population growth and very old age distribution
Answer.3. High fertility, falling mortality rate, rapid population growth and young age distribution
Explanation:
A young growing population is considered an asset for any developing country as it contributes to the working population. Developing countries show expanding population pyramid with maximum age distribution in the pre-reproductive phase i.e., the maximum number of individuals in the young, pre-reproductive phase, high fertility, and high mortality rate.
163. Density of a population (D) is
D = S(size) / W(weight)
D = S(space) / N(number)
D = N(number) / S(space)
None of the above
Answer.3. D = N(number) / S(space)
Explanation:
The number of individuals living within that specific location determines the population density or the number of individuals divided by the size of the area.
D = N/S = Number/Space
164. Each environment supports a limited population depending upon its
Biotic potential
Carrying capacity
Natality
Reproductive potential
Answer.2. Carrying capacity
Explanation:
The carrying capacity of an environment is the maximum population size of a biological species that can be sustained by that specific environment, given the food, habitat, water, and other resources available. Each environment supports a limited population depending on its Carrying capacity.
165. A group of interbreeding organisms found in a particular area is
Species
Community
Tribe
Density
Answer.1. Species
Explanation:
Species are a group of interbreeding organisms. Species possess distinct morphological characters. They interbreed among themselves. They are reproductively isolated from other species. They have a common gene pool.
166. In India, the human population has higher number of younger age group because of
Long life span and low birth rate
Short life span and high birth rate
Short life span and low birth rate
Birth rate is equal to death rate
Answer.2.
Explanation:
In India, the human population has a higher number of younger age groups because of the short life span and high birth rate.
167. The number of births per 1000 is
Growth rate
Conception rate
Reproduction rate
Crude birth rate
Answer.4. Crude birth rate
Explanation:
The crude birth rate is the annual number of live births per 1,000 population. The crude birth rate is generally computed as a ratio.