Name Date Period



Name                                                                                                     Date                     Period

H ES:  Biogeochemical Cycles Review

|Introduction |What does each of the following prefixes mean? |

| |Bio - life |

| |Geo - earth |

| |Chem - chemical |

| | |

| |What are the five (5) biogeochemical cycles? |

| |water (hydrologic), carbon, sulfur, phosphorus, nitrogen |

| | |

| |What drives the cycles? |

| |incoming solar energy and gravity |

| | |

| | |

| | |

| | |

| | |

| | |

| | |

| | |

| | |

| | |

| | |

| | |

| | |

| | |

| | |

| | |

| | |

| | |

| | |

| | |

| | |

|Hydrologic |What are the main processes in the recycling of water? |

|(Water) |evaporation, transpiration, condensation, precipitation, infiltration, percolation, runoff |

| | |

| |Starting in a cloud, describe the journey a molecule of water would take. |

| |fall to the earth in the form of rain, runoff on ground until it infiltrates into the ground, groundwater |

| |movement into the ocean, evaporation from the ocean, condensation into a cloud |

| | |

| |What are the major reservoirs of water? |

| |Ocean (main reservoir), lakes, streams, glaciers, clouds |

| | |

| |What processes help to purify water? |

| |evaporation and precipitation, flowing water above ground through streams and lakes and below ground into |

| |aquifers (especially through wetlands) |

| | |

| |In what three ways have human activities impacted the water cycle? |

| |1)  withdraw large amounts of water leading to groundwater depletion  |

| |2) clear vegetation (agriculture, road, mining…)leading to increased runoff, reducing infiltration, |

| |increasing flooding, and accelerating soil erosion  |

| |3) modify water quality by adding nutrients and other pollutants that can change or impair ecological |

| |processes that purify water |

| | |

| |Can you answer these? |

| | |

| |The process of rainwater entering the soil |

| |Process of converting water vapor to liquid |

| |Conversion of liquid water to vapor  |

| |Evaporation of water from leaves of plants               |

| |Examples include rain, hail, sleet, snow          |

|Carbon |[pic]Why is the carbon cycle important? |

| |it is essential to life as we know it; it is the basic building blocks of carbohydrates, fats, proteins, |

| |DNA, and other organic compounds necessary for life |

| | |

| |What percent of the atmosphere is carbon dioxide gas?  0.037% |

| | |

| |Why is carbon dioxide important to nature’s thermostat? |

| |If too much carbon dioxide is removed then the atmosphere will cool; if not enough carbon dioxide is |

| |removed then the atmosphere will heat up (burning of fossil fuels adds CO2 to the atmosphere) |

| | |

| |In what different forms is carbon found within the biosphere? |

| |carbon dioxide, glucose, fossil fuels, carbonate ions, bicarbonate ions, calcium carbonate |

| | |

| |What are the different forms of carbon used for? |

| |carbon dioxide – photosynthesis          transfer of C between organisms |

| |glucose – aerobic respiration    |

| | |

| |What is calcium carbonate used for? |

| |to build shells and skeletons of marine animals |

| | |

| |Why are decomposers important to the carbon cycle? |

| |help to release the carbon stored in the bodies of dead organisms and return it to the soil |

| | |

| |In what two ways have human activities impacted the carbon cycle? |

| |1)  by clearing trees and other plants that absorb carbon dioxide from the atmosphere |

| |2) add large amounts of carbon dioxide to the atmosphere by burning fossil fuels |

| | |

| | |

| |Could you answer these? |

| | |

| |Remains of plants and animals compacted deep in the earth's crust over thousands of years            |

| |Process by which plants change carbon dioxide and water into carbohydrates and oxygen            |

| |Process by which consumers turn carbohydrates and oxygen into carbon dioxide and water            |

| |Break down dead material into simple components |

|Nitrogen |Why is the nitrogen cycle important? |

| |important component of proteins, DNA, RNA (nitrogenous bases) and other compounds important to living |

| |organisms |

| | |

| |How much of the atmosphere is made up of nitrogen gas?  78% |

| | |

| |Why does nitrogen have to be fixed from nitrogen gas? |

| |nitrogen gas cannot be used directly by plants and animals – nitrogen gas must be converted into another |

| |form |

| | |

| |In what two ways is nitrogen fixed? |

| |1) specialized bacteria called Rhizobium bacteria (which live on the roots of legumes) convert nitrogen gas|

| |into ammonia (a form of nitrogen that can be used by plants) |

| |2) lightning or industry |

| | |

| |What are the different forms of nitrogen used for? |

| |to make nitrogen-containing organic molecules such as DNA, amino acids, and proteins |

| | |

| |In what five ways have human activities impacted the nitrogen cycle? |

| |1) addition of nitric oxide into the atmosphere by the burning or fossil fuels creates acid rain (which can|

| |damage and weaken trees, upset aquatic ecosystems, corrode metals, damage buildings) |

| |2) addition of nitrous oxide) from bacteria living on animal wastes and inorganic fertilizers) which is a |

| |greenhouse gas and contributes to the depletion of the ozone layer |

| |3) removal of nitrogen from topsoil through agricultural practices |

| |4) addition of nitrogen to aquatic ecosystems (runoff of fertilizers, discharging municipal waste) which |

| |leads to too many nutrients in these ecosystems so that lots of plants grow, prevent sunlight from entering|

| |the water, plants die, decomposers break down dead plant material and deplete the water of dissolved |

| |oxygen, animals die |

| |5) destruction of wetlands and forests releasing more nitrogen |

| | |

| | |

| | |

| |And these… |

| | |

| |The return of nitrogen back into the atmosphere       |

| |Converts nitrogen gas into compounds that can enter food webs  |

| |Huge family of plants that house nitrogen fixing bacteria on their roots       |

| |A process that removes nitrogen from the air            |

| |Convert nitrogen-rich organic compounds and wastes into simpler inorganic compounds |

| | |

|Phosphorus |Why is the phosphorus cycle important? |

| |major component of amino acids, ATP, and other nutrients important to the survival of living organisms, DNA|

| |and RNA |

| | |

| |In what different molecules and body parts of living organisms can phosphorus by found? |

| |DNA, RNA, cell membranes (phospholipids) can be found in amino acids, ATP, and in vertebrate bones and |

| |teeth |

| | |

| |Why would phosphorus not typically be found in the atmosphere? |

| |does not typically exist in a gas state |

| | |

| |In what form is phosphorus found in the atmosphere? |

| |Dust (stored in rock) |

| | |

| |Where and what form would phosphorus most likely be found? |

| |phosphate salts in terrestrial rock formations and ocean bottom sediments |

| | |

| |In what two ways is phosphorus transferred? |

| |1) as water runs over rocks it erodes away inorganic compounds that contain phosphorus (runoff) |

| |2) transferred by food webs from producers to consumers |

| | |

| | |

| |Why is phosphorus often considered a limiting factor? |

| |soil typically does not contain a lot of phosphorus which plants need in order to grow, this lack of |

| |phosphorus limits how much a population of plants can grow |

| | |

| |In what three ways are human activities affecting the phosphorus cycle? |

| |1) mine large quantities of phosphate rock for use in fertilizers and detergents |

| |2) reduce available phosphate in tropical forests by removing trees |

| |3) add excess phosphate to aquatic ecosystems (eutrophication) leading to explosive growth of organisms |

| |which ultimately leads to the destruction of the environment |

| | |

| | |

| | |

| | |

| | |

| | |

| | |

| | |

| | |

| | |

| | |

| | |

| | |

|Sulfur |Why is the sulfur cycle important? |

| |component of proteins (amino acids methionine and cysteine), also creates S bonds to make proteins have 3D |

| |structure and also plays a role in allowing organisms to use oxygen |

| |Sulfur makes cell membranes more pliable allowing for improved oxygen transport to the cell and improved |

| |waste transport from the cell- so sulfur would definitely help anyone to remove toxins from the body. |

| |Sulfur helps us regenerate all of our cells so we can heal from the inside, out. |

| | |

| | |

| |Where is much of the earth’s sulfur stored? |

| |underground in rocks and minerals |

| | |

| |How does sulfur enter the atmosphere? |

| |hydrogen sulfide is released from active volcanoes and from organic matter in swamps, bogs, and tidal flats|

| |broken down by anaerobic decomposers |

| |marine algae may produce dimethyl sulfide (which condenses in clouds) |

| | |

| |In what three ways do humans intervene in the sulfur cycle? |

| |     1) burn sulfur-containing coal and oil to produce electric power |

| |2) refine sulfur-containing petroleum to make gasoline, heating oil, and other useful products |

| |3) use smelting to convert sulfur compounds of metallic minerals into free metals such as copper, lead, and|

| |zinc which releases large amounts of sulfur dioxide into the environment |

| | |

| | |

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download