A stable population is described as one in which birth rate equals to death rate, and the number of children is about equal to the number of reproducing adults.

By definition a population is all persons, plants, or animals inhabiting a specified area. A community is the interacting populations within an ecosystem. A gene pool is the total of all alleles of all genes in a population. The definition of an inhabitant is a person or animal that lives in or occupies a place. An organism is any living thing, plant, or animal. 

Populations consist of individuals of the same species in a common area. Communities are made up of groups of populations of different species within a given geographic range. Last, a niche refers to the specialized role and position that a species has within its environment.

A species is "endemic" when it is found only in one particular location. The flightless cormorant, marine iguana, and Galapagos penguin are all examples of species that are endemic to the Galapagos Islands.

Least concerned refers to the lowest risk where species members are abundant. Near threatened means the species is likely to become endangered at some point. Vulnerable means that, in the wild, the species are at high risk for becoming endangered. Endangered is similar to vulnerable, but has a high risk of extinction, not just endangerment. Extinct means there are no more members of the individuals in a species remaining. The correct ranking is as follows: least concerned, near threatened, vulnerable, endangered, and extinct.

Population growth is an underlying cause of depletion and premature extinction of a wild species, but is not a direct cause. On the other hand, habitat loss is a direct cause of depletion and premature extinction of wild species due to processes like over logging, damming rivers, or urban development. Pollution is a direct cause of extinction in the wild, usually caused as streams, rivers, and oceans are polluted. The introduction of an invasive, nonnative species to an environment can create an unbalanced ecosystem, directly causing extinction of wild species. These invasive species are often harmful and fill niches previously occupied by native species. Increasing predator species in an area can significantly reduce or drive prey species to extinction. Similarly, increasing the use of pesticides and pest controls can directly cause extinction of organisms in the affected ecosystem.

A population is a collecting of individuals from the same species. Populations are a unit of organization that has measurable properties, such as population density and home range. Populations are altered by birth and death, immigration, and emigration. 

The correct answer is “metapopulation model.” It describes multiple sub-populations that are connected together in a larger, metapopulation. This is typically shown as patches within a larger landscape. The patches represent sub-populations. Individuals can migrate from one patch to another, but they are all part of the same population.

The correct answer is “evenness.” All the other terms describe life history traits. “Maturity” refers to the age of first reproduction. “Parity” is described as the count of reproduction events. Last, “fecundity” is defined the number of offspring at each reproduction event.

The correct response is “keystone species.” A keystone species makes up a small portion of community; however, it has a major impact on the community structure despite making up a small percentage of the ecosystem that it inhabits. "Dominant species" have large number and large impacts; thus, this answer choice does not fulfill the disproportionate part of the description. "Common species" and "rare species" both have low impacts on the community structure, so they are poor answer choices.