4.20.23 part 2

According to the graphic of the phosphorus cycle, we would expect a loss of phosphorus in the soil in ALL but one of the ways listed below. That is

• plant uptake

• animal manure

• crop harvest

During the water cycle, the sun's energy evaporates water from the surface of Earth. This water is the source of

• precipitation

• respiration

• ozone depletion

Students set up the stream table apparatus seen here. They began their experimentation by building a stream bed with several bends or meanders. A steady flow of water was directed through the opening at the head of the stream. After running the water at a steady rate for two minutes, the students saw an increase in the sediment being deposited at the base of the stream table.

Based on your knowledge of meandering streams, where is stream velocity(speed) the slowest and why?

• Point A, at the start of the stream bed where there is the least friction.

• Point C, where erosion takes place and the stream channel is the deepest

• Point D, where deposition is taking place and the channel is shallowest

Phosphorus is an essential nutrient for plants and animals and is a limiting nutrient for aquatic organisms. Phosphates from fertilizers, sewage and detergents can cause massive algae blooms which, when they die and decay, cause ________________ in freshwater habitats.

• microbial immobilization

• eutrophication

• mineralization

According to the IPCC ( Intergovernmental Panel for Climate Change ) , 1.6 billion tons of carbon dioxide a year are released into the atmosphere due to deforestation. Until the early 1900s, deforestation was the dominant source of increased CO in the atmosphere.

What has surpassed deforestation as the number one anthropogenic source of carbon dioxide emissions?

• cellular respiration

• burning of fossil fuels

• livestock production

CFCs can act as greenhouse gases and as chemicals that reduce the ozone levels in the stratosphere. A worldwide ban on CFCs in 1987 was enacted as part of the Montreal Protocol. However, according to the graph, the level of CFCs did not significantly decrease after 1990.

Which statement best explains the level of CFCs after 1990?

• CFCs are persistent organic pollutants that require a long time to break down.

• CFCs are still being released as volcanoes erupt.

• CFCs are still being released by post - industrial nations at high levels

Scientists have divided the ocean into five main layers. These layers, known as zones, extend from the surface to the most extreme depths where light can no longer penetrate.

Consider the map of the ocean's zones. Formulate a hypothesis regarding life forms as you move from the epipelagic (the sunlight zone) to the hadal zone (the trenches).

• Primary producers change from photosynthetic organisms in the epipelagic zone to chemo-synthesizers in the hadal zone.

• Marine life decreases with depth, both in abundance and biomass, until we reach the hadalpelagic zone, where no life exists.

• We see much biodiversity in the epipelagic zone, including flowering plants and vertebrate animals but in the hadal zone, only bacteria exist.

A greenhouse gas is a gas that absorbs and emits radiant energy within the thermal infrared range. When we hear the term greenhouse gas , we think carbon dioxide, an air pollutant that is the result of fossil fuel combustion. But there are others that are also considered air pollutants: methane, nitrous oxide, fluorinated gases, and ozone. The concentration of methane in the atmosphere has more than doubled since preindustrial times, reaching approximately 1,800 ppb in recent years. Identify the sources of methane in the atmosphere.

All BUT ONE could apply...

• anaerobic decay of organic waste in solid waste landfills

• production and transport of oil and natural gas

• chemical reactions of VOC's in the presence of sunlight

In some places, hazardous substances on a site can be naturally occurring, meaning it was not manufactured or created by human activities. Radon is a well - known naturally occurring hazardous substance that can enter into indoor air and is potentially harmful to humans. Which of these would NOT explain how radon in the environment becomes a hazard and a source of indoor air pollution?

• Every state has homes with radon levels above the EPA recommended concentration

• Radon undergoes radioactive decay and can emit high-energy alpha particles

• Radon gas in rocks and soil can move to air, groundwater, and surface water and diffuse into homes

The carbon cycle describes the process in which carbon atoms continually travel from the atmosphere to the Earth and then back into the atmosphere. Examine the model. What are biotic components of the carbon cycle? Choose ALL that apply.

• decomposers

• cows

• trees

• sunlight

• soil