Chapter 56

Question 1

Conservation biology integrates several fields:

Answer 1

• Ecology
• Physiology
• Molecular biology
• Genetics
• Evolutionary biology

Question 2

Biodiversity has three main components:

Answer 2

• Genetic diversity
• Species diversity
• Ecosystem diversity

Question 3

Genetic Diversity

Answer 3

Refers to genetic variation within a population and between populations

Question 4

Species Diversity

Answer 4

The variety of species in an ecosystem or throughout the biosphere

Question 5

Benefits of genetic and species diversity include:

Answer 5

• Agricultural crops with desired qualities (i.e. virus-resistant commercial rice)
• Prescription drugs can contain substances originally derived from plants (i.e. the rosy periwinkle has alkaloids that inhibit cancer growth)

Question 6

Human activity is _ ecosystem diversity, the variety of ecosystems in the biosphere.

Answer 6

Reducing

Question 7

More than 50% of _ in the contiguous United States have been drained and converted to other ecosystems.

Answer 7

Wetlands

Question 8

The _ that was devastated by Katrina was a wetland that was filled in and made into subdivisions.

Answer 8

New Orleans 9th ward

Question 9

The local extinction of one _ can have a negative impact on other species in an ecosystem.

Answer 9

Species

Question 10

Flying foxes (bats) are important _ and _ in the Pacific Islands.

Answer 10

Pollinators; seed dispersers

Question 11

Ecosystem Services

Answer 11

All the processes through which natural ecosystems and their species help sustain human life

Question 12

Some examples of ecosystem services:

Answer 12

• Purification of air and water
• Detoxification and decomposition of wastes
• Cycling of nutrients
• Moderation of weather extremes

Question 13

Most species loss can be traced to four major threats:

Answer 13

• Habitat loss
• Introduced (invasive species) - species that humans move from native locations to new geographic regions
• Overharvesting - human harvesting of wild plants or animals at rates exceeding the ability of populations of those species to rebound
• Global change - includes alterations in climate, acid precipitation, air pollution, etc.

Question 14

Biologists focusing on conservation at the population and species levels follow two main approaches:

Answer 14

• The small-population approach

- The declining-population approach

Question 15

Small-Population Approach

Answer 15

Studies processes the can make small populations become extinct; the key factor for this approach is the loss of genetic variation that allows a population to respond to environmental changes

Question 16

Declining-Population Approach

Answer 16

Focuses on threatened and endangered populations that show a downward trend, regardless of population size; this approach emphasizes the environmental factors that cause a population to decline

Question 17

Conservation biologists apply understanding of ecological dynamics in establishing protected areas to _ the loss of biodiversity.

Answer 17

Slow

Question 18

Biodiversity Hot Spot

Answer 18

A relatively small area with a great concentration of endemic species and many endangered and threatened species

Question 19

Biodiversity hot spots are good choices for nature _, but identifying them is not always easy.

Answer 19

Reserves

Question 20

The locations of preserves today may be _ for their species in the future.

Answer 20

Unsuitable

Question 21

Human-caused changes in the environment include:

Answer 21

• Nutrient enrichment
• Accumulation of toxins
• Climate change
• Ozone depletion

Question 22

Human activity often removes _ from one part of the biosphere and adds them to another.

Answer 22

Nutrients

Question 23

_ of agricultural crops exports nutrients from the agricultural ecosystem.

Answer 23

Harvest

Question 24

Agriculture leads to the depletion of nutrients in the _.

Answer 24

Soil

Question 25

_ add nitrogen and other nutrients to the agricultural ecosystem.

Answer 25

Fertilizers

Question 26

Humans release many _, including synthetics previously unknown to nature.

Answer 26

Toxic chemicals

Question 27

In some cases, _ persist for long periods in an ecosystem.

Answer 27

Harmful substances

Question 28

One reason toxins are harmful is that they become more _ in successive trophic levels.

Answer 28

Concentrated

Question 29

One pressing problem caused by human activities is the rising level of _ and other greenhouse gases in the atmosphere.

Answer 29

CO2

Question 30

Due to burning of fossil fuels and other human activities, the concentration of _ has been steadily increasing.

Answer 30

Atmospheric CO2

Question 31

Ocean acidification

Answer 31

Decrease in ocean water pH

Question 32

As atmospheric CO2 levels _ and dissolve in the ocean, levels of H2CO3 in the ocean rise.

Answer 32

Increase

Question 33

Leads to a _ in available calcium carbonate for organisms to use in shells and other structures.

Answer 33

Decrease

Question 34

Life of Earth is protected from damaging effects of UV radiation by a protective layer of _ molecules in the atmosphere.

Answer 34

Ozone

Question 35

Satellite studies suggest that the ozone layer has been gradually _ since the mid-1970s.

Answer 35

Thinning

Question 36

The ozone layer is thinnest over _ and southern Australia, New Zealand, and South America.

Answer 36

Antarctica