Test Review using the Quiz Biogeochemical Cycles Yes, as a matter of fact this is on the test. What draws water back to earth? Gravity pulls the water towards the earth. Solar heat warms the liquid to gas which rises. Two forces drive the water (hydrologic) cycle: What is transpiration? Water vapor is released from leaves. What is an aquifer? Underground water Confined aquifer Name two ways water travels from land to the oceans. Surface Runoff (rivers, etc.) Underground flow (Water flows back from the ocean into the aquifer, too.) (The packet was completely wrong.) In the crust. In the form of carbonate (CO 3 ) rocks like limestone. But the atmospheric amount is increasing. How does carbon enter the biotic part of the ecosystem? When carbon dioxide (CO2) is used by plants in photosynthesis to make sugar (C 6 H 12 O 6 ) Carbon! What is a primary producer? A plant. The Trophic Pyramid (Put of food at the end of each name) What is fossil fuel? A fuel created from the remains of living things from long ago How does carbon get in the oceans? It is absorbed from the atmosphere. What percent of the air is nitrogen? 78% 78% Why is nitrogen essential to life? It is used to make amino acids which make proteins which make just about everything. Molecules we eat: Sugar Carbohydrates Fats amino acid From the soil, converted by nitrogen fixing bacteria What is denitrification? Bacteria breaking down nitrates and nitrites from decaying dead matter and converting back to N 2. Why is phosphorus an important biological substance? Its in ATP and DNA What happens to phosphorus that erodes from rocks and soil? It goes in the water and mixes with oxygen to make phosphate (PO 4 ) How are phosphates incorporated into plants and animals? animals eat the plants. Plants absorb it through the roots What is different about the phosphorus cycle as compared to water, carbon and nitrogen? Phosphorus doesnt go into the air. Phosphorus doesnt go into the air.