4.2 Nutrient Cycles

Question 1

What is nitrogen fixation?

Answer 1

the process in which nitrogen is converted into ammonia

Question 2

What is nitrification?

Answer 2

the process in which ammonia is converted into nitrate

Question 3

What is denitrification?

Answer 3

the process in which nitrate is released back into the atmosphere

Question 4

What are the inputs of photosynthesis?

Answer 4

CO2 + H2O + energy (sunlight) = O2 + glucose

Question 5

What are the inputs of cellular respiration?

Answer 5

glucose + O2 = CO2 + H2O + energy (heat)

Question 6

What type of organisms perform the processes of photosynthesis and cellular respiration?

Answer 6

Only plants/producers perform photosynthesis, but all organic matter performs the process of cellular respiration.

Question 7

How do humans affect the carbon cycle?

Answer 7

Humans affect the carbon cycle when burning wood, fossil fuels (oil, coal, natural gasses, etc.), and other forms of carbon.

Question 8

How do humans affect the nitrogen cycle?

Answer 8

burning fossil fuels, application of nitrogen-based fertilizers, etc.

Question 9

What is BTB, and how does it work?

Answer 9

BTB stands for “bromothymol blue.” Scientists use BTB to detect CO2. When CO2 dissolves in water, it forms a weak acid. Solutions with more pH will appear yellow. In solutions with less dissolved CO2, the BTB is blue.

Question 10

How are the pathways of energy and carbon similar to each other? How are they different?

Answer 10

Carbon and energy move along the same path. They both enter through photosynthesis and leave the food chain through cellular respiration. however, carbon is continuously cycling, while energy is lost as heat and it doesn’t come back.