Exam 54: Populations

Population A starts with 100 rabbits and grows at 10 percent per year.Population B starts with 100 rabbits and grows at 15 percent per year.Which shows the total number of individuals in each population after three years?

If 300 mice in a mouse colony are born in January and 150 of them are still alive in September, what is the survivorship rate of these mice from January to September?

Organisms carry out life history trade-offs because they have a limited amount of _______ that they must allocate among survival, growth, and reproduction.

Eighty-one pocket gophers were present in Maddox Field at the start of 2015.During that year, 24 individuals were born and 19 died.Twelve individuals immigrated, and 10 emigrated.How many pocket gophers were present in Maddox Field at the start of 2016?

Women in the twenty-first century are waiting longer to have children than in past generations.This suggests that they are likely making a life history trade-off; that is, they are maximizing

Refer to the mark-recapture equation below. Suppose researchers mark 20 Pacific giant salamanders on the first day of sampling.On the second day, 50 salamanders are captured, of which 10 are marked.In the equation, n₁ is the total number of individuals in the first sample (captured, marked, and released); n₂ is the total number of individuals in the second sample; and M is the number of marked individuals recaptured in the second sample.Which is the best estimate of the overall size of this salamander population?

In a study of the population density of apple maggot flies, 150 flies are captured and marked in the first sampling.Two days later, 300 flies are captured, 15 of which have marks.Based on these results, the estimated number of apple maggot flies in this population would be

A group of ecologists is studying a metapopulation of native bees.The species, an important pollinator, is on the verge of extinction.The ecologists hope to preserve and increase the population.For the greatest chance of success, they should probably focus on

One year, a garden has many tiger swallowtail butterflies.The next year, there is an extreme drought; the flowers do not bloom, and there are no butterflies.In the third year, there is plenty of rain, the flowers bloom, and the butterflies reappear.Why did the butterflies likely reappear?

The patterns and processes of changes in populations are called population

A laboratory population of fruit flies in ideal environmental conditions begins with 100 flies and quickly increases to 124 flies.What is the value of r for this time period?

A clumped dispersion pattern would most likely be found in

Suppose the r value for the population growth curve on this graph equals 1.00.Describe how the curve would appear if the r value were 1.50 instead of 1.00.Explain why this would happen.

The maximum number of individuals of a given species that the environment can support is the environment's _______.

Of 150 mice alive at the start of September, 120 are still alive at the start of October.What was the mortality rate during the month of September?

When Pacific salmon migrate to freshwater streams to spawn, they bring with them marine nutrients.These nutrients fertilize the freshwater habitats when the salmon dies, improving the habitat for juvenile salmon that hatch several months later.Thus, the density of the migrating salmon affects the ability of the new generation to survive.This is an example of the

Advanced fishing technology has made overharvesting of fish populations much easier in the late twentieth and early twenty-first centuries.That is, fishers harvest the fish faster than fish reproduction can replace them.Also, fishers preferentially catch larger fish rather than smaller ones.List two things fishery managers might do to decrease the impact of overharvesting.

Which statement about the South American cane toads that were introduced into Australia as biological control agents is false?

A dog has a very large population of intestinal roundworms.As the population of roundworms increases, the parasites begin to produce fewer eggs.This is an example of population control by

When scientists calculate a per capita birth or death rate, what aspect of the calculation differs from the calculation of a population growth rate?