41) Taiga is characterized by:

A) pines as an early successional stage before deciduous trees, rich understory, and cold climate.

B) few ecological dominants, short growing seasons, and sparse deciduous trees.

C) poor drainage over permafrost, few to no trees, and short growing season; shrubs and sedges dominate.

D) permafrost, short growing seasons, and sparse coniferous trees.

E) coniferous forest, low tree diversity, and no permafrost.

42) Nutrient-poor and often acidic soils with low amounts of organic matter are often found in a ________ ecosystem.

A) desert

B) temperate grassland

C) tropical rain forest

D) deciduous forest

E) chaparral

43) Which of the following statements is true?

A) The temperate deciduous forest is composed of a high diversity of deciduous trees that lose their leaves in the fall because of low soil fertility.

B) Agriculture is often not very successful in a tropical forest because of the poor soils.

C) The high species diversity of a tropical rain forest is supported by a high diversity of soil organisms, high soil fertility, and high rainfall.

D) Agriculture is often not very successful in grasslands because of the poor soils.

44) Is there photosynthetic activity in the benthic zone of the ocean?

A) No, because nutrient availability is too low.

B) No, because this is below the photic zone.

C) Yes, because this is the zone of high light penetration and photosynthetic activity.

D) Yes, because this is the richest zone for nutrient turnover due to microbial activity.

E) Yes, because high light and high nutrient conditions are optimal for phytoplankton production.

45) A marine biologist designs a study to measure net primary productivity in the world’s oceans. She travels to the coastal zone of each continent, takes measurements from north, south, east, and west points along the continent, and combines her data into a global average. Will these measurements be accurate?

A) No, because ocean productivity is greatest past the intertidal zone.

B) Yes, but only if she is sure to sample different climatic zones carefully, because production in different climatic zones may vary by an order of magnitude.

C) No, because the continental edges have much higher productivities than the open ocean.

D) No, because ocean life is greatest near the poles and decreases toward the equator.

E) Yes, because although production in different climate zones differs, the open ocean is well mixed because of strong ocean circulation patterns.

46) The coastal zone is best described as the:

A) area between high and low tide.

B) main profundal zone of the ocean.

C) zone where freshwater and saltwater mix.

D) area between high tide and the edge of the continental shelf.

E) area between low tide and the start of the benthic zone.

47) Coral reefs are highly productive and diverse ecosystems because :

A) they are made of limestone that supports many species of zooplankton with high productivity.

B) corals produce limestone skeletons that create habitats for many ocean species.

C) they are composed of polyps that live in and are adapted to warm, shallow tropical waters with high nutrient availability.

D) they have high turnover rates with high polyp production.

48) In lakes, rooted plants may grow in the ________ zone but no photosynthesizing life is found in the ________ zone.

A) littoral; profundal

B) profundal; pelagic

C) littoral; pelagic

D) benthic; profundal

E) littoral; benthic

49) Oligotrophic lakes have:

A) low oxygen concentrations in the summer.

B) clear water with high production.

C) clear water with low nutrient levels.

D) high nutrient levels and high production by phytoplankton.

E) the largest numbers and diversity of organisms.

50) Which aquatic ecosystem is characterized by ocean tides and river flow stirring up nutrients and producing abundant life?

A) the pelagic zone

B) the intertidal zone

C) estuaries

D) coral reefs

E) wetlands