Quiz 4: Human Populations

Geology/Geography/Oceanography/Atmospheric Sciences

Life expectancy: Explanation The mean age of a newborn infant, which is expected to live in a society, is known as Life expectancy. Life span: The species of oldest age survived by the particular species is known as Life span. Difference between life expectancy and life span includes the following: 1. Life expectancy is defined as an average age of newborn infant that is expected to attain in any society. In contrast, life span is defined as the oldest age to which a species is known to survive. 2. Life span includes maximum age possible by any person in a population, whereas life expectancy is the average age at death of everyone in a population. 3. Life expectancy in most societies probably has been 35 to 40 years, while the oldest age means Life span that can be certified by written records was 122 years.

Productivity, diversity, complexity, resilience, and structure are exhibited by all communities in an ecosystem to some extent: Explanation Productivity, diversity, complexity, resilience, and structure are exhibited to some extent by all communities and ecosystems. For instance, local plants on Hawaii are primarily responsible for primary productivity, as they convert sunlight into the energy that is eventually cycle the chain. Additionally, speciation and variations of Hawaii species in the environment of islands is due to diversity. The complexity of the ecosystem comes as a result of millions of years of chance evolution. Resilience and structure develops accordingly in a fully mature ecosystem. Thus, productivity, diversity, complexity, resilience, and structures are exhibited to some extend by all communities and ecosystem.

Dependency ratio: Explanation The ratio of non-working persons associated with working persons in a resident is called as dependency ratio. In United States, Dependency ratio is increasing by means of declining in work population, which supports larger number of retired persons. Since, the resident is becoming older and more retirees to sustain by few people, at working age. Fall down of communal security can occur if this continues; as an outcome. In contrast, some calls calling for better movement to United States remain the mean age of the population down in order to have jobs for sufficient workers.