Exam 39: Biodiversity and People

Although humans appear to be responsible for the current extinction crisis, scientists are confident that human did not contribute to any previous extinction event because

Many prescription drugs have been derived from plants, and numerous potential drugs may never be discovered if the loss of tropical rainforest plants continues.

The behavior of _______ most closely resembles that of invasive species?

For many, stinging insects such as honeybees are a nuisance. Why might it not be a good idea simply to poison all the honeybees and save people from the temporary pain of a sting or even an allergic reaction to such insects?

Numerous reasons have been proposed for maintaining the natural biodiversity of the Earth, but not all can be judged as scientifically valid. For example, science lack the ability to evaluate

Abandoned turtle nest cavities are often used as nesting sites for species unable to dig their own cavities. If turtles are driven to extinction, which of the following is the most likely effect on these other species?

Researchers have observed a direct proportional relationship between the _______ of an ecosystem (the annual growth of plant matter) and its biodiversity.

Because they are visually interesting and relatively accessible, _______ are presently the most thoroughly studied group of organisms on Earth.

Cataclysmic events have the potential to render vast regions of the earth uninhabitable and exterminate their biota; the most recent event occurred 65 million years ago when a(n) _______struck the Earth.

How many previous, well-documented mass extinctions have occurred in Earth's history?

How can the significance of human involvement be assessed in this current mass extinction event?

Ecosystems that are not diverse tend to have a higher productivity that those with greater diversities.

More than half of the presently identified species on Earth are

Although water treatment facilities exist, in most of the world humans are depend on healthy ecosystems for clean water.

Many yet unknown species of insects are likely to live in the nearly inaccessible branches of the ___________ of tropical rainforests.

Although many groups continue to contain undescribed members, scientists have finally completed the classification of all fishes.

Scientists estimate that about 90 percent of the world's species have been catalogued by humans, and anticipate completing the inventory within the next decade.

During the past 30 years amphibians have declined at an alarming rate. Some scientists believe the decline is occurring because amphibians are

Studies have shown that when an ecosystem's biodiversity is high,

The end of the Permian period approximately 250 million years ago coincides with a significant biological event; at that time