Chapter 21a. tropical rain forests cover about 2% of the earth's land surface, and contain about 2% of th 21b. the outermost layer of the atmosphere is the troposphere. of the earth biodiversity 22a. oxygen is the most abundant gas in the atmosphere. 22b. complex arrangements of feeding patterns in ecosystems are best described as food webs. ny co 23a. ozone, a gaseous oj molecule that filters out harmful uv radiation is found in the stratosphere. 23b. ecologists study interactions within and among the five levels of organizations of cell, atom, molecule, organism, and biosphere. 24a. bacteria and fungi are typically categorized as decomposers in an ecosystem. 24b. process of photosynthesis is best shown as carbon dioxide + water + solar energyglucose+ oxygen. 25a. a grizzly bear eating blueberries is best categorized as tertiary consumer 25b. autotrophs are also known as consumers. 26a. organisms that feed on both plants and animals are called omnivores animals the break down bodies of dead plants and animals into nutrients that are released into the soil or water are called detritivores. 27a. the process that results in alcoholic beverages is anaerobic respiration. 27b. a hawk would be considered a tertiary consumer 28a. if the producers in an ecosystem capture 40,000 energy units, assuming average efficiency of energy 28b. net primary productivity is usually reported as the energy output of a specified area of producers over a transfer, 4,000 energy units can likely be successfully converted into secondary consumer biomass. given time. 29a. nitrogen makes up approximately 85% of the volume of the atmosphere. 29b. the biogeochemical cycle of carbon does not include the atmosphere as a temporary reservoir. 30a. ammonium ions are converted to nitrite ions and nitrate ions through the process of denitrification. 30b. decomposers or detritus feeders are essential to us because they eat waste and recycle nutrients.