population and growth regulation quiz

Which of the following is an assumption of the geometric growth equation?

- reproduction can (and does) occur continuously - population growth is discrete - the growth rate is constant

quiz question: Assume a population of bacteria is growing exponentially under an r = 1.5 per hour. What is the doubling time of this population?

.5 h

quiz question: A bacterial population has a doubling time of 0.5 h. What is its intrinsic growth rate (r)?

1.386

quiz question: The population density of a particular insect species was determined to be 15,000 adults per hectare in the summer of 1996, and 21,000 adults per hectare in the summer of 1997, Based on these population estimates, what is your estimate of λ, the annual rate of geometric growth?

1.4

quiz question: If there are 150 cheatgrass plants in a single plot of land at year 10 and the population is growing with a finite rate of increase (λ) of 1.2, approximately how many plants were in the initial invasion at time zero? Assume geometric growth.

24

quiz question: If there are 150 cheatgrass plants in a single plot of land at year 5 and the population is growing with a finite rate of increase (λ) of 1.2, approximately how many plants were in the initial invasion at time zero? Assume geometric growth.

60

quiz question: A local population of Japanese beetles is growing geometrically with λ = 1.1 (per year). The population on July 31 this year consists of 800 adults. How many adults will be in this population on July 31 in TWO years?

968

quiz question: Which is likely to follow an exponential increase in population size? I. A population of mice that has consumed most of the food in its habitat II. A small population of rats recently introduced to an island with many resources III. Bacteria recently placed on a new petri dish with suitable growth medium

II & III only

quiz question: The age structure of a population is often represented by a pyramid. What does an age structure pyramid with a broad base and a narrow top indicate about a population?

The population is growing.

quiz question: The term that describes the maximum number of individuals in a population that a habitat can support is:

carrying capacity

quiz question: In the logistic growth model, the per-capita growth rate __________ as population size _________.

decreases, increases

quiz question: Factors that can impact a population that vary with the density of a population are called:

density-dependent factors

quiz question: A declining population of an endangered butterfly is determined to have an exponential rate of decrease of r = −0.02. What is the corresponding value of λ for this population?

greater than 0 less than 1

quiz question: Under positive density dependence, population growth rate ______

increases as populations become larger

quiz question: In a population growing according to the exponential growth model, population size is ______

not limited

A population is defined as a group of organisms:

of the same species occupying a particular space at a particular time

quiz question: Negative density dependence occurs when the ______

per capita population growth rate decreases as population becomes larger.

quiz question: In a study of a particular plant species, populations with fewer than 100 individuals had substantially reduced fecundity (fewer fruits per flower and fewer seeds per fruit), than larger populations. This is an example of

positive density dependence

quiz question: The logistic growth form is sometimes also described as a:

s-shaped curve

quiz question: Population growth rates sometimes increase with increasing population density, especially at low population densities, as seen in certain fish stocks. We refer to this kind phenomenon as Allee effect.

true