Population ecology - class-XI

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'.

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. 

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.

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

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

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 

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.

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.

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.

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. 

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).

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'.

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.

Population density is a measurement of population per unit area or unit volume. Formulas of population density is total population divided by total area. It can also be represented by number of births/no. of individuals and number of births/space.

When the necessary conditions for sustaining life are adequately available, like the food, habitat, water, the maximum number of members of a species that the environment can sustain indefinitely can be called as the carrying capacity of the environment. Thus, the correct answer is option A.

Carrying capacity is the maximum size of the population of a species that a certain environment can support for an extended period of time. Overgrazing of pasture would make it barren. Once population overshoots the carrying capacity, it starts decreasing as at this point. An overgrazed pasture would no longer support the cattle leading them to starve or look for another food source. Thus, the correct answer is B.

The carrying capacity of an environment is the maximum population it can support with available resources. Carrying capacity is one of the limiting factors for population increase.

The carrying capacity of a population is determined by its limiting resources. Carrying capacity is the upper limit of an ecosystem upto which it can Provide the basic needs to the population under given circumstances.

Population carrying capacity of any environment is the maximum population size of a species that can have indefinite sustained growth. Here, for the deer being 1000.

Carrying capacity is the maximum number of population species that the particular environment can survive. In this case, the number of individuals that are mortal and the number of new births will be equal. SO, the mortality rate will be equal to birth rate. 

In a population, if the number of individuals are more..the population density will be more. And if the population density is less..the number of individuals will be less. Density of a population is determined by the number of individuals residing in a particular area. 

• How many organisms there are per unit area is referred to as density.

The logistic growth equation is dN/dt = rN(1 - N/K), where K represents the carrying capacity. This model accounts for environmental resistance as the population approaches K.

Non biological parameters of water can be easily used to determine the population density of the fishes.

In the given example, K represents carrying capacity or the maximum capacity that can exist and N represents the actual population present at a particular time. If in a population showing sigmoid growth curve the value of K - N/K is 0.95, then the carrying capacity of this population has not been substantially realized and it can accommodate more organisms. This population has maximum growth rate because it shows that environment can sustain more population.

Carrying capacity is the maximum population size of a species that an ecosystem can support indefinitely. When carrying capacity is reached, a population can survive on the resources available without depleting the overall availability of the resources. When a population is below the carrying capacity, the individuals have access to more than enough resources to survive. When a population grows and begins to reach the carrying capacity, the population begins using resources at an equal rate to which the resources are created. This often creates competition between individuals for the available resources. As a result, some individuals will die when they cannot get enough resources and others will not reproduce because they do not have the resources to support offspring. Environmental resistance leads to the establishment of a carrying capacity.

The formula for finding the population density is: 

Human population is directly affected by - 

If the population of a species is transferred to the more suitable environment, then it will show  protection against enemies. Populations are groups of individuals belonging to the same species that live in the same region at the same time. Population density is a measure of the number of organisms that make up a population in a defined area. In the suitable environment, the species of the population becomes more strong to fight with enemies and protect themselves.

Dispersion pattern is a species-specific feature and shows the spatial relationship between population members present in the specific area. When members of same species inhibit the growth of another individual of the same species present nearby or those with defined territories exhibits the uniform pattern of distribution. In the present example, hawk population faces intraspecific competition for limited nesting sites and therefore will be present at a uniform distance from each other.