The Dark Biosphere
Nitrogen’s Chemical Alphabet
Algae, Oxygen, & Death
The Carbon & Nitrogen Ledger
100

Greenhouse gases cause global temperatures to rise by doing this to heat.

What is trapping it (preventing it from radiating into space)?

100

This is the chemical formula (NH3) for the substance produced immediately after nitrogen is "fixed" by bacteria.

What is Ammonia?

100

This is the term for the movement of excess fertilizer from a farm into a nearby stream or river.

What is Runoff?

100

This is the general term for any cycle—like carbon or nitrogen—that moves elements between living things and the physical environment.

What is a Biogeochemical Cycle?

200

These specific microorganisms serve as the "producers" at the base of hydrothermal vent food webs.

What are Chemoautotrophs (or Sulfurimonas bacteria)?

200

In the process of nitrification, bacteria convert ammonia into these two specific forms (NO2- and NO3-).

What are Nitrites and Nitrates?

200

The text describes this as the "rapid growth" of algae and cyanobacteria due to excess human nutrients.

What is an Algal Bloom?

200

This specific greenhouse gas (N2O) is formed when fossil fuels are burned and contributes to climate change.

What is Nitrous Oxide?

300

If a producer has 10,000 Joules of energy, how much energy is available to a Secondary Consumer?

What is 100 Joules? (10% of 10%)

300

In an energy pyramid, this level always contains the most "Matter" (Biomass)

What is the Producer level (the bottom)?

300

This is the main reason why global temperatures have risen over the past century.

What is the rapid increase of Greenhouse Gases (like CO2) in the atmosphere?

300

oceans and plants cannot absorb all human emissions, meaning carbon is entering the atmosphere "______" than it can cycle back.

What is Faster?

400

Before humans started burning fuels, this was the primary natural "source" that returned carbon from the deep geosphere to the atmosphere

What are Volcanic Eruptions?

400

This is the biological reason why an algal bloom removes oxygen from a lake or ocean.

What is through Cellular Respiration?

400

These two physical forces transform buried organic matter into coal, oil, and natural gas over millions of years.

What are Heat and Pressure?

400

Algal blooms harm aquatic life by doing these two things: blocking sunlight and using up this specific gas.

What is Dissolved Oxygen?

500

besides fossil fuels, carbon is also stored in the geosphere as this common type of sedimentary rock.

What is Limestone?

500

Human activity disrupts the "balance" of cycles by creating too many "________" and not enough "______."

What are Sources (releasers) and Sinks (absorbers)?

500

This is the reason why we cannot use the N2 gas that we breathe in.

What is because we cannot break the bonds.

500

Carbon is entering the atmosphere faster than it can cycle back into these, which are meant for long-term storage.

What are Reservoirs?