Biology · Geography

Population Dynamics

978 Questions

Explore key concepts in population dynamics through these practice questions. The focus is on demographic transition models, population pyramids, and life history theory. These topics are useful for general studies and biology exams.

Demographic transition theoryPopulation pyramidsMathematical growth modelsLife history theory

Population Dynamics Questions

Multiple choice zoology human population population ecology population size population and how it changes

Total number of individuals of a species per unit area and per unit time is called 

  1. Population size

  2. Population density

  3. Demography

  4. Population dynamics
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Population density is the number of individuals present per unit area or volume at a given time. If the total number of individuals is represented by letter N and the number of units of space (area for land organisms and volume for water organisms) by letter S, then the population density D can be represented as D =N/S. For instance, number of animals per square kilometer, number of trees per acre in a forest, etc. So, the correct answer is 'Population density'.

Multiple choice zoology human population population ecology population size population and how it changes

For which of the following cases, population density can be easily determined by utulising non-biological parameter?

  1. Fish density

  2. Density of Bactria in culture plate

  3. Siberian cranes at Bharatpur wetlands

  4. Tiger census
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Sometimes, for certain ecological investigations, there is no need to the absolute population densities. Relative densities serve the  purpose equally well. In this case, population size is indirectly estimated without actually counting them. For example, the number of fishes caught per trap is good enough measure of its total population density in the lake. The tiger census in our National park and tiger reserves is often based on pug marks (animal's ft print ) and fecal pellets. So, the correct answer is 'Tiger census'.
Multiple choice zoology human population population ecology population size population and how it changes

Which of the following is not an example of using relative density to measure population density in a certain area?

  1. Counting pug marks of tigers to find population density of tigers a forest

  2. Counting the number of fishes caught in a trap to find population density of fishes in a lake

  3. Measuring biomass of bacterial culture to find out population density of bacteria in a petri dish

  4. Measuring biomass of phytoplanktons in 1 cc water to find out population density of phytoplanktons in a lake
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Option D is correct,  because measuring of biomass of phytoplanktons is very time consuming and It is a microscopic task to measure only PHYTOPLANKTON in 1 cc water except other species found in the given water. 

Multiple choice zoology human population population ecology population size population and how it changes

In some cases, polpulation density is measured in terms of biomass rather than in terms of numbers becouse ________________________.

  1. it is a more meaningful measure when the considered organisms vary greatly in size.

  2. it is more convenient when population is huge and counting is impossible or very time consuming

  3. it is a relatively constant measure

  4. both a and b
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Although the total number is most approprite measure of population density, but in some cases it is difficult to determine.In a forest area, spouse there are 200 Pathenium plants but only a single huge banyan tree with a large canopy. Stating that the population density of banyan is low relative to that of Pathenium, amount to underestimating the great role of bayan in that forest community.

Multiple choice zoology human population population ecology population size population and how it changes

In N = population density at time t, then population density at time +1 can be written as 
$N _t+1 = N _1 + [(A +B) - (C + D)]$
Select the correct option for A, B, C and D in the above equation. 

  1. A can be mortality and B can be natality

  2. B can be immigration and C can be natality

  3. C can be mortality and D can be immigration

  4. A can be natality and D can be emigration
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A and B are nasality and immigration. They add to population density. C and D are mortality and emigration. They decrease population density 

Multiple choice zoology human population population ecology population size population and how it changes

Which of the following would necessarily decrease the density of a population in a given habitat?

  1. Natality > mortality

  2. Immigration > emigration

  3. Mortality and emigration

  4. Natality and immigration
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Population density in a given habitat is influenced by four processes:
- Natality : It is the number of birth in a population during a given period of time,
- Mortality : It is the number of deaths in a population during a given period of time.
-Immigration : Number of individuals coming from other habitats in a given period of time 
-Emigration : Number of individuals exiting form a given population in a given period of time.

Mortality and emigration will, therefore decrease the population density while natality and immigration will increase it.
So, the correct answer is 'Mortality and emigration'.

Multiple choice zoology human population population ecology population size population and how it changes

Population density refers to

  1. Number of women per thousand men

  2. Number of individuals per square kilometer at any given time

  3. Number of men per thousand women

  4. Number of men died in a year
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Population density is defined as the number of individuals of a species per unit area or volume at a specific time. It is a fundamental measure in ecology.

Multiple choice zoology human population population ecology population size population and how it changes
The average population density of developing countries as India in comparison to developed countries like USA is

  1. Equal

  2. Less

  3. More

  4. Everchanging
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Population Density is defined as the number of people living per square km. As per the provisional population totals of Census 2011, the population density of India has been 382 persons per square kilometer. Population density in the United States was last measured at 34.86 in 2014, according to the World Bank. Therefore population density of developing country like India is more than developed country like the USA. So, the correct answer is option D.

Multiple choice zoology human population population ecology population size population and how it changes

Population density means

  1. The number of human per unit area

  2. The number of human in a unit area at a specific time

  3. The concentration of human population at a place

  4. None of above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Population density of a species is the number of individual of a species per unit area or volume e.g.,number of animals per square km. 

Multiple choice zoology human population population ecology population size population and how it changes

Carrying capacity of a population is determined by

  1. Limiting resources

  2. Mortality rate

  3. Natality rate

  4. Predation
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Carrying capacity is the maximum population size of a species that an environment can sustain indefinitely, given the food, habitat, water, and other necessities available in the environment (limiting resources).

Multiple choice zoology human population population ecology population size population and how it changes

The carrying capacity of a population is determined by its

  1. limiting resources

  2. natality

  3. mortality

  4. population growth rate
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
The carrying capacity of an environment refers to the maximum number of organisms that it can support. It is usually denoted by a K and is determined by the limiting resources like food and space.
So, the correct answer is 'limiting resources'
Multiple choice zoology human population population ecology population size population and how it changes

Logistic growth occurs when there is

  1. A fixed carrying capacity

  2. Asexual reproduction only

  3. Sexual reproduction only

  4. No inhibition from crowding
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Logistic growth occurs when the population size increases with time but levels off after reaching a maximum which is known as the carrying capacity. Carrying capacity is fixed and is the maximum number of individuals that can be supported by a population. So, the correct option is 'a fixed carrying capacity'.

Multiple choice zoology human population population ecology population size population and how it changes

Which of the following statements is correct?

  1. The number of organisms can decrease but never increase once a population reaches its carrying capacity

  2. All populations experience exponential growth once they reach carrying capacity

  3. A population always grows rapidly once it reaches its carrying capacity

  4. Limiting factors can influence the number of organisms in a population once it reaches its carrying capacity
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Answer : 
i) Carrying Capacity-when the number of births equals the number of deaths, the population is at its carrying capacity for that habitat. 
ii) If resources are being used faster than they are being replenished, then the species has firstly exceeded its carrying capacity. 
iii) If this occurs, later the population will then decrease in size due to intraspecific competition for resources.

So the correct answer is option D. Limiting factors can influence the number of organisms in a population once it reaches its carrying capacity.
Multiple choice zoology human population population ecology population size population and how it changes

Which of the following statements defines the density of population?

  1. Number of persons living per unit area

  2. Number of persons living in a country

  3. Change in the number of inhabitants of a country during a specific period of time

  4. Absolute numbers added every year
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A population is a unit of biotic community made up of near permanent group of an interbreeding individual of a species found in a space or geographical area at a particular time. It is called local population or deme. Increasing population is a challenging issue for the developing country like India. If the population increases more than its carrying capacity it may lead to food crisis resulting in famines, hunger and poor health, acute shortage of shelter and clothing. Spreading awareness among the people about the ill-effects of increasing population may be helpful to control the over increasing population. So, the correct answer is option D.