High school Biology; Populations and Communities Unit Exam

If there are 40 turtles in a 5 square-kilometre area, what is the population density?

8 turtles per square-kilometer.

What is a species' fundamental niche?

A fundamental niche is the niche an organism would inhabit in the absence of competition with other species.

What is a niche?

A niche is everything that affects a given organism, including the organism's sources of subsistence, the environmental factors present in its habitat, and other factors such as climate.

What is a species' realized niche?

A realized niche is the niche an organism inhabits in the presence of competition with other species.

Which of the following have contributed to historical increases in the global human population?

Advances in medicine and the production of food.

Which types of factors contribute to the carrying capacity of a population?

Carrying capacity is the maximum population size in the logistic model of population growth where as this capacity is dictated by density-dependent factors.

What happens to the given effect of Density-Dependent factors as a population approaches carrying capacity?

Density-Dependent factors have a greater effect.

Which types of factors limit population growth?

Due to certain factors, population cannot grow infinitely larger. These factors are referred to as limiting factors and they all actively participate in limiting population growth.

If the global human population is increasing by 0.012 per capita per year, which of the following is true?

Next year, the population will increase by 0.012 per person.

Why does population growth slow as size increases in the logistic model?

Population growth is affected by limiting factors, some of which have a greater effect on population size within a given area increases. These are called density-dependent factors and these factors slow population growth as a population increases.

What is the process by which two species share different parts of a limited resource?

Resource partitioning.

What two variables are necessary to calculate population growth?

The birth rate and death rate are the two factors required to calculate population growth

Which type of animal is most flexible? a) one with a wide fundamental niche b) one with a wide realized niche c) one that is a strict niche specialist d) one that is extremely competitive

The correct answer is "a", one with a wide fundamental niche.

What will be the distribution pattern of a population of snakes that have no social interactions and whose prey and shelter are abundant? a) randomly dispersed b) evenly dispersed c) clumped d) need more information

The correct answer is "a", randomly dispersed

What will always happen when two species try to fill the same niche? a) extinction b) exclusion c) partitioning d) competition

The correct answer is "c", competition.

Which of these involves estimating the size of a population by counting only the members of the population in a particular area and then using this to estimate the size of the entire population over its entire inhabited area? a) counting the entire population b) mark-and-recapture c) sampling d) population index

The correct answer is "c", sampling.

What does population density tell us that population size does not?

The density of a population is its size divided by the area it inhabits, therefore describing the area of the habit of a population relative to its size.

Some predators rely on speed to catch their prey. How would you expect the prey to evolve in response?

The evolution of predator and prey species depends on each other. When one evolves, the other is likely to evolve in a compensatory fashion. Comparatively, prey that becomes faster will be more successful.

What is the relationship between an organism's fundamental niche and its realized niche?

The fundamental niche of an organism is usually larger than its realized niche.

What is the per capita growth rate of the global human population?

The global human population has been steadily increasing in size for hundreds of years making the growth rate positive.

What is the approximate size of the global human population?

The global human population reached 6 billion in 1999 and has continued to increase at a per capita rate of 0.012 per year now currently approaching 8 billion. It is widely considered to be at 7 billion.

If a population of 100 caterpillars is growing at 0.5 per capita per year, how many caterpillars will there be after one year?

The number of individuals added to a population after one year is the per capita growth rate times the population size. These will be added to the current population and achieve a total of 150 caterpillars.

If the population size of a host decreases, how will this affect the population size of its parasites?

The parasite population will decrease in size.

If the population size of a predator increases, how will this affect the population size of its prey?

The prey population will decrease in size.

What are the two types of predators?

The two types of predators are carnivores and herbivores.