environmental test

The United Nations estimates that ______ percent of the world's marine fisheries are being overexploited or are being fully exploited.

70

Which of the following are the three groups of organisms that appear to be greatly affected by climate change?

Corals Arctic species Amphibians

How do forest plantations differ from natural forests?

Forest plantations often consist largely of exotic species. Forest plantations have even-aged trees. Forest plantation trees mature to harvestable size faster than those from a typical naturally reproducing forest.

Which of the following statements correctly describe the main concerns raised by tropical deforestation?

Loss of tropical rainforests means less rainfall is trapped, runoff is more rapid, and soil erosion in the region is exacerbated. Loss of tropical forests is significantly reducing the species diversity of the world.

Which of the following are the primary reasons why biodiversity in freshwater ecosystems is under threat from human activity?

River water withdrawal is high in some areas, causing rivers to shrink in size or dry up. Rivers have been channelized to facilitate navigation. Dams have been built for flood control and for hydroelectric power.

the three types of organism that appear to be greatly affected by climate change are ______, ______, and ______.

amphibians; corals; Arctic species

The process of looking for potentially valuable genetic resources and biochemical compounds in nature is called ______.

bio-prospecting

The conversion of native lands to agricultural lands, excessive nutrient loading, and climate change are all major causes of ______ today.

biodiversity loss

Which of the following examples correctly identify major causes of biodiversity loss today? (Select all that apply.)

conservation of native lands to agriculture climate change excessive nutrient loading

Desertification is the process of ______.

converting arid and semiarid land to desert because of improper land use by humans

about 40 percent of the world's land surface has been converted to ______.

cropland and permanent pasture

Which of the following are deforestation activities?

cuttings timber for fuel harvesting trees for building materials clearing forest for farming

Extinction is ________.

elimination of all the individuals of a particular kind of species

______ occurs when humans harvest organisms faster than the organisms are able to reproduce.

overexploitation

Approximately how many species on Earth are known to science and have been taxonomically described?

1.4 million

According to the IUCN's Red List of threatened species, there are currently around ______ species threatened with extinction.

21,000

According to the International Union for Conservation of Nature and Natural Resources (IUCN), about ______ percent of threatened species are under threat because of habitat loss.

80 to 90 percent

Which of the following statements correctly identify environmental impacts from aquaculture?

Increased nutrient levels can be found in the surrounding water, causing algal blooms that negatively affect other fisheries. Farm-raised fish may escape and establish exotic populations that compete with native species. New genetic stocks may be released that interbreed with wild fish, altering the genetic makeup of wild populations.

Which of the following are examples of overexploitation?

Now highly endangered, rhinos continue to be hunted and killed for their horns, which are made into dagger handles or powders sold as aphrodisiacs. In the United States, many wild cactus plants are collected and placed in people's yards, resulting in drastic declines in wild population numbers.

Which of the following groups of examples all have been known to contribute to declines in salmon runs in the Pacific Northwest for over a century?

Overharvesting, poor hatchery management, logging activities

Why is there a high degree of endemism in river systems?

River systems are linear, with a variety of different habitats from their headwaters to their mouths.

Which of the following statements is true regarding the net change in forest area from 1990-2015 in different parts of the world or for different forest types?

Temperate parts of the world, such as North America, Europe, and China, are maintaining or increasing their forests.

Which of the following statements correctly relates urban and industrial land conversion to biodiversity loss?

The expansion of impermeable surfaces prevents plant growth and diverts rainfall to local streams, threatening most species of wildlife in the area.

Why do scientists think that Arctic and Antarctic species declines are associated with a warming planet?

They have observed a reduction in the extent of the sea ice and prey availability.

Which of the following are negative impacts resulting from the presence of exotic species?

They may kill or directly compete with native species and drive them to extinction. Their management can result in soil and/or freshwater pollution, such as from the application of pesticides. There may be an increase in vectors or carriers of diseases that harm human health.

Why do scientists think that amphibian declines are associated with a warming planet?

They think that the prevalence of a fungal disease that has become common in the last few decades is linked to temperature increases.

How do aquaculture facilities pollute their surrounding environment?

Uneaten food and waste from the farm-raised fish facilities may be released into the surrounding environment, leading to algal blooms.

Which of the following is a correct example of consumption of bush meat?

Using nets, a family captures migrating birds in the forest to be eaten at a holiday feast.

Which of the following species reduction or extermination efforts have received support, for the most part, from humans?

Wolves in Alaska and Canada Malaria parasite Smallpox

mutations

changes in the genetic information of an animal

selective breading

choosing certain desired characteristics to be passed on to offspring over many generations

Reforestation is a process in which ______.

clear-cut sites are naturally reseeded or trees are replanted

reforestation is a process in which

clear-cut sites are naturally reseeded or trees are replanted

______ is the forest-harvesting method that involves the removal of all the trees in a large area. In ______, small areas have all the trees removed, but these areas are surrounded by areas of untouched forest. In ______, individual, mature, high-value trees are removed, without disrupting the forest ecosystem.

clear-cutting; patchwork clear-cutting; selective harvesting

what human activity has resulted in the extinction of species

damming streams to produce water power harvesting of wood for fuel and building materials clearing land for farming

Why have salmon runs in the Pacific Northwest have been in decline for more than a century?

dams poor hatchery management logging activities overharvesting

the removal of forests for fuel, building materials, or conversion to agriculture are all considered forest-destroying activities, often called

deforestation

Overgrazing and the removal of trees for firewood are primary causes of ______.

desertification

___________ is the process of converting arid and semiarid land to desert because of improper use by humans.

desertification

Which of the following are factors that influence the ecosystem diversity of an area?

difference in soil type natural events topographic changes

Overexploitation, habitat loss, the introduction__________ of species, predator __________and control activities, __________and change are major human impacts that threaten to reduce biodiversity.

exotic pest climate

sexual reproduction's

generation of new genetic combinations during fertilization

Human populations differ in appearance from one global region to another. This is an example of ______ diversity.

genetic

A species of snail is made up of many populations that each display unique gene expressions, such as populations of red-colored snails, brown snails, and white snails. This is an example of ______ diversity.

genetic diversity

Which of the following are the primary activities resulting in habitat loss?

grazing by livestock conversion to urban and industrial landscapes forestry farming

In North America, ______ and ______ were systematically reduced to small, isolated populations, partly because they preyed upon domesticated animals.

grizzly bears; mountain lions

Forestry, farming, grazing by livestock, and conversion to urban and industrial landscapes are the primary activities resulting in ______.

habitat loss

which of the following factors increase the likelihood that a species will become extinct?

having specialized niche having a low population density being found in small areas

The use of fire to clear land, the harvesting of wood for fuel and building materials, and the damming of rivers to provide water power are all types of ______ activities that have resulted in the extinction of species.

human

In recent times, which of the following has significantly modified natural ecosystems, leading to major increases in present-day extinction rates and major declines in global biodiversity?

humans

Which of the following are major human impacts that threaten to reduce biodiversity?

introudction of exotic species predator and pest control activities climate change habiatat loss overexploitation

Which of the following are factors that influence the genetic diversity of a population?

migration sexual reproduction mutations

which of the following are factors that positively influence the species diversity of a particular location?

migration the geologic and evolutionary history of a region

natural forests

mixed-species trees variable-aged trees

the larger the area studied, the ______ kinds of ecosystems are present.

more

migration

movement of individuals of a species from one population to another

_____ create patches of habitats in early successional stages, increasing the diversity of ecosystems in a region.

natural events

Rhino populations that are hunted and killed for their horns, which are made into dagger handles or powders sold as aphrodisiacs, to the point that their populations are now threatened by extinction is an example of ______ of a species.

overexploitation

Which of the following are causes of desertification?

overgrazzing; deforestation

ranking the following species based on its probability of becoming extinct soon.

rats rattlesnakes cheetah

Habitat loss results in a(n) ______ in the numbers of species that were a part of the original ecosystem.

reduction

______ is a process in which clear-cut sites are naturally reseeded or trees are replanted.

reforestation

forest p lantations

single-species trees even-aged trees

The geologic and evolutionary history of a region, migration, and human activity are all factors that influence the ______ diversity of a particular location.

species

Knowing that biodiversity is under threat, some nations have begun ______ for the future.

storing genetic material such as in seed banks

A region with many different categories of organisms, such as frogs, birds, mammals, insects, pine trees, and mosses, is said to have high ______ richness, as compared to a region that has high numbers of different species of ferns and mosses, which would be described as having high ______ richness.

taxonomic, species

biodiversity is

the term used to describe the diversity of genes, species in an ecosystems in a region

The removal of forests often leads to a hotter, drier regional climate because in an intact forest, the ______.

trees would transpire large quantities of water, creating fog or clouds trees shade the soil, keeping it cooler

rank the regions based on their level of species diversity highest to lowest

tropical rainforest grassland tundra

The ______ is a region with high species diversity, and the ______ is a region with low species diversity.

tropical rainforest, artic tundra

Why are tropical forests less likely to regenerate after logging than temperate forests?

tropical soils have lower fertility tropical soils are more erodible

______ forests are less likely to regenerate after logging than ______ forests because they have ______.

tropical; temperate; fewer species of trees and plants available to reestablish the site

The removal of forests often leads to more rapid runoff of water and greater soil erosion because in an intact forest, the ______.

water has more time to sink into the soil and recharge groundwater trees hold water on their surfaces, reducing the amount and rate of runoff

the removal of forests often leads to more rapid runoff of water and greater soil erosion because in an intact forest, the ______.

water has more time to sink into the soil and recharge groundwater trees hold water on their surfaces, reducing the amount and rate of runoff