Exam 3: Biodiversity

The variety of life comes in many types. Briefly explain three of them.

List some of the pros and cons of using biological control agents.

Humans depend on biodiversity in many ways. Which of the following is considered to be an "option value"?

Some people value biodiversity because of the intrinsic value. Justify why humans should protect biodiversity based on the intrinsic value of biodiversity.

What is a biological "hot spot"?

What are the top reasons to protect biodiversity? Justify your answers.

Explain the aesthetic value of biodiversity.

Four types of benefits that biodiversity provides for humans would be

Biodiversity refers to the

Gray wolves once roamed the western portions of North America from Alaska to Mexico. Gray wolves prey on bison, deer, elk, and moose. These prey had been depleted by hunting by settlers. Ranches and farms were built near gray wolf habitat. The wolves thus began to prey on livestock. When the federal government set aside the Greater Yellowstone Ecosystem (GYE) as a national park in 1872, about 300-400 wolves were present, preying mostly on elk and bison (Yellowstone Association 1996). Fearing the wolves' impact on elk and bison herds as well as livestock owned by area ranchers, the federal government began eradicating the wolf population. Bounty programs that continued until 1965 offered as much as $50 per wolf. By the 1930s, wolves had been effectively eliminated from the 48 contiguous states and Mexico and remained in high numbers only in Alaska. The elk population then grew. Elk grazed on plants and soon plant populations declined. Plants such as willow trees and aspen were negatively affected. Song birds depended on the trees for habitat, river banks remain stable because of the trees, but now the trees were not producing saplings (young trees). Which of the following is the best conclusion to make based on this situation?

The present rate of species loss on Earth may be as high as 20,000 species lost per year. At this rate by the year 2050 one-third of the world's species could be lost, many of which have not even been discovered. Never before has a single species, humans, been responsible for the loss of so many species. Based on this information, what is the best conclusion?

What evidence shows that species have lived and gone extinct?

Suppose that a lake commonly used for fishing, both for a food resource and for pleasure, becomes depleted due to overfishing. The community decides it will bring in another fish in large numbers to help reestablished the fish population. The new fish, the Nile perch, is a large, voracious eater, and adapts well to new locations. Which of the following is the best conclusion for this scenario?

Which of the following statements is false?

Explain this statement: Some variation of species may be more important than other variation.