Chapter 22 and 27 - Biogeochemical Cycles and Human Interactions

Question 1

Biological Nitrogen Fixation

Answer 1

nitrogen gas (N2) from the atmosphere is incorporated into the tissue of certain plants.

Question 2

Nitrification

Answer 2

Breakdown of nitrogen-containing organic compounds into nitrates and nitrites

Question 3

Denitrification

Answer 3

Reduction of nitrates and nitrites to nitrogen by microrganisms

Question 4

Organism that are responsible for biological nitrogen fixation

Answer 4

Bacteria

Question 5

What input from the nitrogen cycle yeilds the most nitrogen

Answer 5

the process of decomosition

Question 6

Effects of Acidic Deposition

Answer 6

• Severe in the soils with low buffering capacity
• Aquatic systems are especially sensitive
• Effects on forest systems – lack of frost hardiness, other nutrients become limiting, decrease in root biomass

Question 7

Atmospheric deposition

Answer 7

whereby precipitation (rain, snow, fog), particles, aerosols, and gases move from the atmosphere to the earth’s surface

Question 8

Effects of oxidation of iron pyrite

Answer 8

Poisons water

Question 9

What gases are responsible for atmospheric decomposition

Answer 9

ozone, nitrogen- and sulphur-containing

Question 10

Bioaccumilation

Answer 10

a process of accumulation of chemicals in an organism that takes place if the rate of intake exceeds the rate of excretion
- EX: ddt

Question 11

How does DDT affect some fish eating birds

Answer 11

Making there egg shells thin and weak

Question 12

Why do we see a fluctuation in atmopheric carbon on an annual basis in the northern hemisphere

Answer 12

Plants do not take up CO2 in winter but take it up in the summer