Deck 32: Human Impact on the Biosphere

Question 1

Which subfield of biology helps support conservation biology?

A) ecology
B) forestry
C) genetics
D) evolutionary biology
E) All of these are correct.

Answer 1

Conservation biology aims to solve today and future biological challenges. Biological challenges involve different aspects of biology. Thus, knowledge of different fields is necessary. A conservation biologist must be knowledgeable in ecology, forestry, genetics, and evolutionary biology.
Hence, the correct answer is (e) all of these are correct.
Currently, the environment has several challenging issues. Several issues include global warming, desertification, and water shortage. Knowledge of ecology helps conservation biologists. However, a conservation biologist must know other subfields of biology. Hence, the option (a) ecology is incorrect.
Conservation biologists are concerned with the declining forests. People are clearing the forests. They build houses and cities. These activities reduce biodiversity. Knowledge of forestry may help conservation biologists solve these kinds of problems. However, conservation biology involves other subfields of biology too. Hence, the option (b) forestry is incorrect.
Conservation biology also involves genetics. However, other subfields also support conservation biology. Hence, the option (c) genetics is incorrect.
Evolutionary biology helps conservation biologists understand populations through several generations. Human activities could shape the evolution of populations. However, other subfields of biology also support conservation biology. Hence, the option (d) evolutionary biology is incorrect.

Question 2

What is the main goal of conservation biology?

A) conserving natural resources for current and future generations
B) increasing agricultural yields
C) decreasing human mortality
D) identifying species that provide a monetary value to humans
E) All of these are correct.

Answer 2

Conservation biology is a broad field of biology. Conservation biology involves many subfields of biology. These subfields support conservation biology: physiology, field biology, systematics, behavior, veterinary science, range management, agronomy, and wildlife management. Conservation biology has one main goal: conserve natural resources for the present and future generations.
Hence, the correct answer is (a) conserving natural resources for current and future generations.
Conservation biology may aim to increase agricultural yield. Increasing agricultural yield would conserve natural resources. For instance, increasing agricultural yield may conserve water. Increasing agricultural yield may help conservation biology reaches its goal. However, the main goal of conservation biology is not to increase agricultural yield. Hence, the option (b) increasing agricultural yields is incorrect.
Conservation biology mainly deals with conserving natural resources. Humans could be considered natural resources. Conservation biology may extend its target to decrease human mortality. However, the main goal is not to decrease human mortality. Hence, the option (c) decreasing human mortality is incorrect.
Several species could serve valuable medical purposes. Some critical medicines are derived from plants. Other animal species are useful for scientific and medical experimentations. Identifying these species could provide monetary value to human. Conserving these species is one challenge for conservation biologists. However, conservation biology's main goal is not to identify these species. Hence, the option (d) identifying species that provide monetary value to humans is incorrect.
The main goal of conservation biology is to conserve natural resources. This goal is broad. Many or unlimited number of projects may be necessary to achieve this goal. The solutions could be many. More solutions may need to be developed in the future. Thus, the limited number of activities cannot be the main goal of conservation biology. Hence, the option (e) all of these are correct is incorrect.

Question 3

Which of the following is an indirect value of biodiversity?

A) participation in biogeochemical cycles
B) participation in waste disposal
C) provision of fresh water
D) prevention of soil erosion
E) All of these are correct.

Answer 3

Biodiversity has several indirect values. Biogeochemical cycles depend on diverse organisms. For instance, the biogeochemical cycle of nitrogen depends on bacteria. In addition, biodiversity contributes to the disposal of waste. For example, decomposers break down toxic, trash, and other items. Biodiversity helps retain freshwater. Soil with plants is able to absorb rainwater. Furthermore, biodiversity helps prevent soil erosion. The plants could hold the soil better. Soil without plants is easily washed away during precipitation.
Hence, the correct answer is (e) all of these are correct.
The maintenance of the biogeochemical cycles depends on a diverse ecosystem. Biodiversity provides the essential organisms. These organisms contribute to the continuation of the biogeochemical cycles. However, biodiversity has other indirect values. Hence, the option (a) participation in biogeochemical cycles is incorrect.
Bacteria and decomposers are good at breaking down materials. Some materials could be time consuming and expensive to break down by humans. Thus, biodiversity contributes to waste disposable. However, there are other values to biodiversity. Hence, the option (b) participation in waste disposal is incorrect.
Many living organisms depend on fresh water for survival. Soil with plants is able to retain more water. Thus, biodiversity helps retain fresh water. However, there are other indirect values. Hence, the option (c) provision of fresh water is incorrect.
Plants have roots. The roots could hold the soil together. Thus, biodiversity helps prevent soil erosion. However, there are other indirect values. Hence, the option (d) prevention of soil erosion is incorrect.

Question 4

The preservation of ecosystems indirectly provides fresh water because

A) trees produce water as a result of photosynthesis.
B) animals excrete water-based products.
C) forests soak up water and release it slowly.
D) ecosystems promote the growth of bacteria that release water into the environment.
E) plants trap moisture with their leaves.

Question 5

Desertification typically happens because

A) deserts naturally expand in size.
B) humans allow overgrazing.
C) desert animals wander into adjacent areas for food.
D) humans tap into limited water supplies for their water needs in the nearby desert.

Question 6

Soils in tropical rain forests are typically nutrient-poor because

A) they receive more water than other ecosystems.
B) they are sandy.
C) nitrogen-fixing bacteria are absent.
D) nutrients are tied up in vegetation.

Question 7

Most of the fresh water in the world is used for

A) drinking.
B) supporting industry.
C) irrigating crops.
D) cooking.
E) bathing.

Question 8

A major negative effect of the dumping of raw sewage into lakes and rivers is

A) oxygen depletion.
B) the buildup of carbon.
C) a reduction of light penetration into the water.
D) an increase in populations of small fish.

Question 9

Which of the following will help conserve fresh water?

A) saltwater intrusion
B) drought-tolerant crops
C) increased irrigation
D) use of water contained in aquifers

Question 10

The first green revolution resulted from the development of

A) high-responder wheat and rice varieties.
B) effective irrigation systems.
C) transgenic crop plants.
D) crops designed for animal feed.

Question 11

Show how the following diagram must change in order to develop a sustainable society.

Question 12

Which of the following would help make both urban and rural areas more sustainable?

A) plant multipurpose trees
B) use low-flow irrigation to conserve water
C) use more solar energy
D) plant cover crops
E) use green roofs