A small island has stable populations of plants and animals, including one species of hawk as the only predator. The removal of the hawks could cause ____________ population size.

Many indicators show that temperatures are increasing, and climate patterns are changing on a global scale.  What is NOT a likely result of these changes?

Considering that the scientific method includes making observations, formulating a hypothesis to explain the observations, testing the hypothesis with experimentation, analyzing data from experiments, and drawing conclusions about the meaning of the data, which of the following statements about a species of flowering plant represents an experiment?

Which ecosystem would be least affected if sunlight did not reach the Earth for an extended period of time?

In a study locality, rabbits are the only prey of coyotes.  Biologists estimated the population sizes of rabbits and coyotes each year for 5 years and the data are shown in the table below.  Interpret these data about predator/prey relationships.    

All animals must get oxygen for respiration.  Which of the following is NOT involved in this critical function?

Two of Darwin’s finches display a character displacement when they occur as sympatric species. Which of the statements correctly interprets the graph?    

A species of beetle is active at night and sleeps in the bark of trees during the day.  These beetles normally mate during the night on the sides of trees.  The forest they live in has lizards that hunt insects by vision and birds that hunt insects by sounds made by their prey.  Which of the following represents the most adaptive way for male and female beetles to find each other for mating?

According to the phylogenetic tree below, modern-day mammals are most closely related to which modern group of reptiles?

Recent extinctions of species can be attributed to several causes.  Which of the following is not considered a major cause of such extinctions?