Exam 12: Population Growth and Regulation

Which reflects positive density-dependent population regulation? I. Small populations of flowers produce fewer seeds per individual than large populations of flowers. II. Large groups of birds are better able to detect and avoid predators than small groups of birds. III. The probability that a squirrel will be killed by a forest predator does not depend on the size of the squirrel population.

The following table shows the survival and fecundity of a flowering plant. Use it to answer questions 47 to 49. -What is the R₀ for this species?

Which accurately describes the inflection point in the logistic growth model? I. Population growth slows after the inflection point. II. The inflection point is equal to the carrying capacity. III. The highest growth rate occurs at the inflection point.

A biologist grew 10 groups of flowers in 1-square-metre plots of soil. In five plots, the biologist planted 20 flowers, and in the other five plots, the biologist planted 100 flowers. At the end of the summer, the biologist counted the seeds that each flower produced and found 100 seeds per plant in the plot with 20 plants and 500 seeds per plant in the plot with 100 plants. This is an example of

The graph shows one possible answer; students will have their own values. The figure should show log-transformed mass on the y axis and log-transformed survival on the x axis. The points they plot should form a negative slope. -A biologist studies a population of birds for 25 years. Each year the biologist records the amount of rainfall and the density of birds (number of birds per 100 square metres). Additionally, the biologist determines the survival rate for eggs laid that year. The biologist then plots egg survival rate against both rainfall (graph a) and bird density (graph b). In each plot the individual points represent the data for one year of the study. Based on these data, does this population of birds appear to have positive density-dependent population regulation, negative density-dependent population regulation, or density-independent population regulation? As part of your answer, list the prediction for each type of population regulation and explain whether the data meet that prediction.

Example: Correct plot student might draw; student may vary units on y axis. -Using the logistic growth model, draw a line that shows the relationship between per capita growth rate (y axis) and population size (x axis) for a hypothetical population with a carrying capacity of 500 individuals. Explain how the slope relates to changes in population size over time and give an example of an environmental factor that could cause a population to follow a logistic model of population growth.

A species of louse (an external parasite) infests salmon. Researchers have found that the lice have difficulty finding a mate when there are only a few lice on an individual fish. The lice find mates more easily and produce more offspring when there are many lice on an individual fish. This is an example of

Use this figure for questions 2 and 3. -Which plot is consistent with an exponential growth model when r > 0?

Which of the following statements about the logistic growth model is accurate? I. The per capita rate of population increase declines as population size increases. II. The overall rate of population increase is highest at K/2. III. The overall rate of population growth is negative when N is greater than K/2.

Define population doubling time. Starting with the model for exponential population growth, explain how to derive the formula for population doubling time.

A disadvantage of static life tables is that

According to the exponential growth model, which would reduce a population's doubling time?

Which reflects density-independent population regulation? I. a winter storm that kills birds with equal probability regardless of bird abundance II. a drought that kills a higher proportion of plants when there are many plants and a smaller proportion when there are fewer plants III. a lethal disease that is more easily transmitted when animals are found in high abundance than in low abundance

You are a biologist studying deer populations in four parks: Chagrin, Bedford, Bradley, and Brookside. These four parks are all the same size, and they have similar weather. You estimate deer population size in October 2011, before winter comes. Then you estimate the size of the herd the next year, in October 2012. The data are listed in the table: Explain whether each of the following statements is supported by the data and why or why not. I. These populations have exponential growth. II. The changes in population size are density dependent. III. All of these populations are below their carrying capacity.

In the logistic growth model, which term determines the maximum number of individuals a population can sustain?

Which factors could limit a species' carrying capacity? I. the amount of food available II. the number of eggs a female can produce III. the number of nesting sites present

Which reflects negative density dependence? I. A fungus infects and kills plants at a higher rate when they are abundant than when they are rare. II. A group of birds has a higher per capita survival rate when it is large than when it is small. III. A large population of deer exhausts local food supplies and has a high risk of death; a small population has plentiful food and low risk of death.

The larvae of a carnivorous species of salamander inhabit ponds. When the pond contains few larvae, they mostly eat small invertebrates and have a high survival rate. When there are many salamander larvae in a pond, the larvae will also cannibalize each other and have a low survival rate. This is an example of

Describe the similarities and differences between a cohort life table and a static life table. Give an actual example of each.

According to an exponential growth population model, when the number of births is less than the number of deaths,