Due to their low density, females of a species of turtles have difficulty finding mates. As a result, the population's growth rate has been low, despite ample resources. This is an example of

A. an Allee effect.
B. environmental stochasticity.
C. genetic drift.
D. isolation by distance.

Apsychologist has developed a series of personality inventories and wants to determine if they are valid. one of the scales measures perfectionism, so he asks a colleague for advice on how to establish the validity of this scale. the colleague tells him that if he were to find a sample of people with personality disorder, these people would obtain high scores on a scale that measures perfectionism.

According to the federal regulations, which of the following studies meets the definition of research with human subjects? a study of twenty 4th grade classrooms in which researchers ask the schools to systematically vary the time of day reading is taught, and collect weekly assessments of reading comprehension for each child over a three-month period.the collection of data, by a playground designer hired by the superintendent of schools, about the physical dimensions of school playgrounds, presence of fencing, and the kinds of equipment currently provided.a feasibility study for implementing a year-round school program, focusing on economic issues such a facilities utilization and transportation costs.an analysis of aggregate data comparing statewide high school graduation rates provided by the state department of public instruction, using county tax information.

Martha entered into a contract with terry, an art dealer. according to the contract, terry was to supply 18 th century artifacts to martha for the play she was directing, and martha was ready to pay $50,000 for this. another director needed the same artifacts and was ready to pay $60,000. terry decided not to sell the artifacts to martha. in this case, the court may order terry to: