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?  

Evidence suggests that an asteroid struck the Gulf of Mexico near what is now the Yucatan Peninsula about 65 million years ago.  What was likely the cause of the cause of the loss of many plants?

What features of charophytes provides evidence for charophytes being the closests relative to land plants?

Which organ system plays the least role in maintaining optimal conditions of the animal body?