Chapter 3

Question 1

Which is NOT an example of an abiotic component of an ecosystem?

air
sunlight
fungi
water

Answer 1

fungi

Question 2

Which is NOT characteristic of most ecosystems?

biotic components
abiotic components
distinct boundaries
a wide range of sizes

Answer 2

distinct boundaries

Question 3

Which is produced during photosynthesis?
I. glucose
II. sulfur
III. carbon dioxide

II and III
I and III
I only
III only

Answer 3

I only

Question 4

Which could be a cause of decreased evapotranspiration?

increased precipitation
increased percolation
increased vegetation
decreased runoff

Answer 4

increased percolation

Question 5

At which trophic level are eagles that consume fish that eat zooplankton that eat algae?

secondary consumers
producers
tertiary consumers
primary consumers

Answer 5

secondary consumers

Question 6

At which trophic level do organisms use a process that produces oxygen as a waste product?

producers
secondary consumers
tertiary consumers
primary consumers

Answer 6

producers

Question 7

Which statement about precision agriculture is false?

a) It increases the efficiency of fertilizer application.
b) It focuses on areas where crops are growing poorly.
c) It prevents fertilizer runoff to local streams and rivers.
d) It uses satellite imagery and GPS technology.

Answer 7

It prevents fertilizer runoff to local streams and rivers.

Question 8

Which food chain found on the Serengeti Plain is in the correct sequence from lowest trophic level to highest?

a) gazelles–decomposers–cheetahs–shrubs
b) shrubs–decomposers–cheetahs–gazelles
c) shrubs–gazelles–cheetahs–decomposers
d) decomposers–cheetahs–shrubs–gazelles

Answer 8

shrubs–gazelles–cheetahs–decomposers

Question 9

Which macronutrient is required by humans in the largest amounts?

calcium
nitrogen
sulfur
potassium

Answer 9

Nitrogen

Question 10

Roughly what percentage of incoming solar energy is converted into chemical energy by producers?

99
1
50
80

Answer 10

1%

Question 11

The net primary productivity of an ecosystem is 1 kg C/m2/year, and the energy needed by the producers for their own respiration is 1.5 kg kg C/m2/year. The gross primary productivity of such an ecosystem would be

2.0 kg C/m2/year.
1.5 kg C/m2/year.
0.5 kg C/m2/year.
2.5 kg C/m2/year.

Answer 11

2.5 kg C/m2/year.

Question 12

A particular plot of land can produce 700 kg of beef per hectare. Beef sells for $4/kg. If that land is converted to producing corn, which sells for $0.15/kg, approximately how much will the farmer make selling corn? Assume 10 percent ecological efficiency.

$1,000
$500
$3,000
$100

Question 13

Which biogeochemical cycle does NOT have a gaseous component?

I. potassium
II. sulfur
III. phosphorus

I and III
II only
I and II
II and III

Answer 13

II and III

Question 14

Which statement about the carbon cycle is TRUE?

a) Carbon transfer from photosynthesis is in steady state with respiration and death.
b) The majority of dead biomass is accumulated in sedimentation.
c) Most of the carbon entering the oceans is from terrestrial ecosystems.
d) Combustion of carbon is equivalent in mass to sedimentation.

Question 15

Human interaction with the nitrogen cycle is primarily due to

a) the decreased assimilation of ammonium and nitrates.
b) the breakdown of ammonium into ammonia for industrial uses.
c)the acceleration of the nitrification process in aquatic ecosystems.
d) the leaching of nitrates into terrestrial ecosystems.

Question 16

Research at Hubbard Brook showed that stream nitrate concentrations in two watersheds were ________ before clear-cutting, and that after one watershed was clearcut, its stream nitrate concentration was ________.

a) similar; increased
b) different; decreased
c) different; increased
d) similar; decreased

Question 17

Small inputs of this substance, commonly a limiting factor in aquatic ecosystems, can result in algal blooms and dead zones.

a) dissolved oxygen
b) sulfur
c) dissolved carbon dioxide
d) phosphorus

Answer 17

Phosporus

Question 18

Name 6 macronutrients needed by organisms in relatively large amounts

Answer 18

Nitrogen, phosporous, potassium, calcium, magnesium, and sulfur

Question 19

After a severe drought, the productivity in an ecosystem took many years to return to pre-drought conditions. This observation indicates that the ecosystem has

low resilience.
high resistance.
low resistance.
high resilience.

Answer 19

low resilience.

Question 20

Which describes a key difference between photosynthesis and aerobic respiration?

a) Photosynthesis generates organic compounds whereas aerobic respiration generates inorganic compounds.
b) Aerobic respiration has a higher energy efficiency than photosynthesis.
c) Photosynthesis releases energy whereas aerobic respiration consumes energy.
d) Photosynthesis consumes chemical energy whereas aerobic respiration generates chemical energy.

Answer 20

Photosynthesis consumes chemical energy whereas aerobic respiration generates chemical energy.

Question 21

Ocean acidification represents a key component of the

a) nitrogen cycle.
b) sulfur cycle.
c) carbon cycle.
d) hydrologic cycle.

Answer 21

Carbon Cycle