Tag: population and how it changes

Questions Related to population and how it changes

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

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

  1. Population size

  2. Population density

  3. Demography

  4. Population dynamics

Show answer
Correct Option: B
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'.

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

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

  1. Fish density

  2. Density of Bactria in culture plate

  3. Siberian cranes at Bharatpur wetlands

  4. Tiger census

Show answer
Correct Option: D
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'.

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

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

  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

Show answer
Correct Option: D
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. 

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

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

  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

Show answer
Correct Option: D
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.

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. 

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

  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

Show answer
Correct Option: D
Explanation:

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

Which of the following factors influence population density under normal conditions?

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

  1. Deaths

  2. Immigration

  3. Emigration

  4. Both (A) and (B)

Show answer
Correct Option: A
Explanation:

Under normal condition births and deaths influence density of a population the other two factors being only active under special condition 

The maximum possible number of individuals that a habitat can support is called its _________________.

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

  1. fecundity

  2. surviving ability

  3. carrying capacity

  4. biotin potential

Show answer
Correct Option: C
Explanation:

In nature, a given habitat has resources to support a certain number of individuals of a population, beyond which no further growth is possible. This limit is called as nature's carrying capacity (K) for that species in that habitat 

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

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

  1. Natality > mortality

  2. Immigration > emigration

  3. Mortality and emigration

  4. Natality and immigration

Show answer
Correct Option: C
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'.

Population density refers to

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

  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

Show answer
Correct Option: B
The average population density of developing countries as India in comparison to developed countries like USA is
zoology human population population ecology population size population and how it changes

  1. Equal

  2. Less

  3. More

  4. Everchanging

Show answer
Correct Option: C
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.