Question

name:____ period:__ date:__ score:____ cycles of matter set b 1. which process in the carbon - cycle converts carbon dioxide into organic compounds? a. cellular respiration b. decomposition c. photosynthesis d. combustion 2. in the nitrogen cycle, what form of nitrogen can plants directly absorb from the soil? a. nitrogen gas (n₂) b. nitrates (no₃⁻) c. ammonia (nh₃) d. nitrites (no₂⁻) 3. what is the primary source of oxygen in earths atmosphere? a. volcanic eruptions b. decomposition c. ocean evaporation d. plant photosynthesis 4. which process releases water vapor into the atmosphere as part of the water cycle? a. transpiration b. infiltration c. condensation d. precipitation

Explanation:

1. Photosynthesis uses carbon - dioxide and water to produce organic compounds and oxygen. Cellular respiration releases carbon - dioxide, decomposition breaks down organic matter to release carbon - dioxide, and combustion also releases carbon - dioxide.
2. Plants can directly absorb nitrates (NO₃⁻) from the soil. Nitrogen gas (N₂) needs to be fixed first, ammonia (NH₃) can be converted to nitrates, and nitrites (NO₂⁻) are less commonly directly absorbed compared to nitrates.
3. Plant photosynthesis is the primary source of oxygen in the atmosphere. Volcanic eruptions release various gases but not mainly oxygen, decomposition consumes oxygen in most cases, and ocean evaporation is part of the water cycle and not a major oxygen source.
4. Transpiration is the process by which plants release water vapor into the atmosphere as part of the water cycle. Infiltration is water seeping into the soil, condensation is water vapor turning into liquid, and precipitation is water falling from the atmosphere.

Answer:

1. c. Photosynthesis
2. b. Nitrates (NO₃⁻)
3. d. Plant Photosynthesis
4. a. Transpiration