T or F- Elements such as oxygen, nitrogen, and carbon cycle through a system once.
FALSE
Two hydrogen atoms and one oxygen atom form this molecule essential for life.
water
What gas do animals exhale that provides carbon to the atmosphere?
Carbon dioxide (CO2)
The air is about what percent nitrogen gas? Give the number
78
What primary gas released by plants during photosynthesis do animals need to breathe?
Oxygen (O2)
T or F-Nitrogen, as it is found in the atmosphere, can be used by plants and animals.
False
The process by which liquid water heats up and turns into water vapor.
Evaporation
What organisms break down dead plants and animals, returning carbon back to the soil and air?
Decomposers (bacteria and fungi)
How animals get the nitrogen needed to build proteins and DNA?
by eating plants or other animals
Approximately what percentage of Earth's atmosphere is made up of oxygen gas?
21%
Organisms like bacteria, fungi, and earthworms that break down dead material and return nutrients to the soil.
decomposers
The process where water vapor cools down high in the atmosphere and forms clouds.
Condensation
What term describes the chemical burning of fossil fuels or wood, which releases carbon into the atmosphere?
Combustion
A natural weather phenomenon high in energy that can break nitrogen bonds in the air and fix small amounts into the soil.
Lighting
Do plants use oxygen?
Yes (they perform cellular respiration continuously when sunlight is not available for photosynthesis )
Special bacteria living in soil or plant root nodules that convert unusable nitrogen gas into usable compounds like nitrates.
Nitrogen-fixing bacteria (or nitrogen fixers)
What primary source of energy drives the entire global water cycle?
The Sun
Shellfish and corals use dissolved carbon in the ocean to build which hard protective body structures?
Shells (or calcium carbonate skeletons)
What specific group of microscopic organisms is responsible for converting atmospheric nitrogen gas into usable nitrates, and in what plant structures do many of them live?
Nitrogen-fixing Bacteria living in the root nodules of plants
Besides the atmosphere, in what giant Earth reservoir is the majority of Earth's oxygen chemically bound inside rocks and minerals?
The Earth's crust
According to the Law of Conservation of Matter, what happens to the total number of carbon, hydrogen, and oxygen atoms during photosynthesis and cellular respiration?
The total number and types of atoms remain exactly the same; they are only rearranged.
What percentage of Earth's total water supply is salty ocean water?
97%
What holds the title of the largest reservoir of dissolved carbon dioxide on Earth?
the ocean
Most organisms cannot use free nitrogen gas. Name the process that converts free nitrogen into a usable form for plants
Nitrogen fixation
During photosynthesis, plant cells split what molecule to release oxygen gas into the air?
Water (H2O)