Chapter 16: Conservation and Biodiversity

How many species do biologists estimate to be currently on earth?

between five million and one hundred million Scientists are unsure of the actual number. Many species still are unknown and may become extinct before they can be identified.

A flagship species is one that:

conservationists use to increase public knowledge and support for all conservation issues. A flagship species increases public awareness and support for conservation issues in general. China's giant panda is a good example.

An important conservation strategy is to connect isolated habitat patches with ______________, thus ensuring migration routes for plants and animals.

corridors Natural corridors connecting isolated habitat patches would ensure migration for plants and animals.

Overexploitation:

is a major factor responsible for species extinction. Overexploitation includes the killing of animals for food, pelts, tusks or other body parts, and medicinal products. It is a major factor responsible for species extinction and, ultimately, the reduction of biodiversity.

Global warming results from increased carbon dioxide in the atmosphere because:

less heat can radiate from the earth into space. Increased carbon dioxide in the atmosphere prevents some heat from radiating into space.

Biodiversity hotspots are defined by which two criteria?

species richness and degree of threat In many cases, it is the encroachment of humans that causes biodiversity hotspots. As the name implies, these hotspots have a rich diversity of species, many of which are under threat.

Burning fossil fuels releases, among others, two gases primarily responsible for acid rain. These two gases are:

sulfur dioxide and nitrogen dioxide. Sulfur dioxide and nitrogen dioxide are the two gases primarily responsible for acid rain.

When sulfur dioxide (SO2) reacts with water vapor in the atmosphere, it produces:

sulfuric acid (H2SO4). Sulfuric acid is produced when sulfur dioxide reacts with water vapor.

What is landscape conservation?

the conservation of habitats, ecological processes, and species All of these are needed to ensure a viable environment is maintained.

What defines an exotic species?

a species introduced by human activities to areas other than the species' native range This can be disastrous for native species.

Which of the following is considered a form of habitat degradation? agriculture fisheries logging All of the above.

All of the above. All of the above practices are a form of habitat loss and degradation—the chief reason for the loss or impending loss of many species.

Biodiversity is considered to be important because of: the direct economic benefit to humans, such as medicines and food. the symbolic value that elements of the natural world can provide. the aesthetic value it holds. its potential for helping humans understand the processes that gave rise to the diversity we see. All of the above.

All of the above. Unfortunately, a great deal of the earth's biodiversity is under threat. Many species will become extinct even before scientists are able to discover them.

What is the difference between an endangered species and a threatened species?

An endangered species is under imminent threat of extinction; a threatened species is vulnerable to extinction. Species can move from one status to another as conditions change.

Which of the following is FALSE regarding biodiversity hotspots? Biodiversity hotspots cover less than 1% of the world's area. Biodiversity hotspots contain 20% or more of the world's species. Examples of biodiversity hotspots are the coral reefs and tropical rain forests. There are 25 hotspots identified around the world. These are regions of the world having significant reservoirs of biodiversity without any threat of destruction.

These are regions of the world having significant reservoirs of biodiversity without any threat of destruction. Unfortunately, these regions of the world are under high threat of destruction.

Which of the following habitats has the greatest biodiversity?

This question cannot be answered because defining biodiversity is not completely objective. Biodiversity can be defined in many ways and is essentially a function of one's values, biases, and interests.

Exotic species can disrupt ecosystems because:

they frequently have no predators in their new habitat and grow unchecked. As a result of their unchecked population growth, they can outcompete other species, including endemic ones.