G185 - Chapter 2 Assignment

Which of the following statements about systems and feedbacks are true? (select all that apply)

A. Both positive and negative feedback can lead to system instability and collapse. B. A system is essentially a network, with materials and energy flowing from one component to another C. With positive feedback, an increase in a state variable leads to further increases in that same variable D. With negative feedback, an increase in a state variable leads to further increases in that same variable E. All systems are closed B., C.

Match the trophic level name to the percentage of energy that it obtains from the original capture of energy from the sun.

100% - Producers 16.1% - Herbivores 1.8% - Primary Carnivores 0.1% - Top Carnivores 24.2% - Decomposers

Drag and drop each molecule in the word bank to the correct type of biological molecule

- Carbohydrate: Cellulose, Starch - Nucleic Acid: DNA, RNA - Lipids: Hormones, Fats, Oils - Proteins: Enzymes

Classify each description below as either part of the Hydrologic Cycle, Carbon Cycle, Nitrogen Cycle, Sulfur Cycle, or Phosphorus Cycle by dragging the correct term to the box next to the description

- Carbon Cycle: includes the processes of cellular respiration, photosynthesis, and combustion; excess gases released by combustion put this cycle out of balance - Nitrogen Cycle: bacteria are a critical part of this cycle; the atmospheric gas must be fixed into a form that organisms can use - Phosphorus Cycle: does not have an atmospheric component; weathering of rocks is an important process - Hydrologic cycle: evaporation from the oceans is a critical component - Sulfur cycle: in this cycle, burning of fossil fuels contributes to acid rain

Match each diagram of a molecule with the correct scientific name for that molecule

- Hydrogen: H2 - Oxygen: O2 - Nitrogen: N2 - Hydrochloric Acid: HCl - Water: H2O - Carbon Dioxide: CO2 - Sulfur Dioxide: SO2 - Nitrogen Dioxide: NO2 - Methane: CH4

_________

- Positive feedback: plant -> inhibits bird populations -> bird -> (eat) beetle -> (eat) plant - Negative feedback: plant -> provides habitat for birds -> bird -> (eat) beetle -> (eat) plant

Energy enters ecosystems from the sun (represented as the bottom of the arrow). Place the trophic levels and their relative biomass in the appropriate ascending order.

- Secondary Consumers --- Primary Consumers ------ Primary Producers

Which of the following are accurate descriptions of water? (select all that apply)

A. Water molecules are polar, and thus dissolve other polar or ionic substances B. Water molecules are nonadhesive, tending to repel each other forcefully, resulting in a low surface tension C. Water shrinks when it crystallizes, and ice is more dense than liquid water D. The slow response of water to temperature change helps moderate global temperatures E. Water's high heat of vaporization makes evaporation an effective way for many organisms to shed excess heat A., D., E.

Biogeochemical cycling is defined as

A. the movement of matter within or between ecosystems

Which biogeochemical cycle does NOT have an atmospheric component?

A. the phosphorus cycle

How do consumers harness the sun's power and use it as an energy source?

B. by eating producers at the bottom of the food chain

Which of the following does NOT contribute to the fact that tertiary consumers are rare in ecosystems compared to members of lower trophic levels?

C. Tertiary consumers always have greater body mass than primary and secondary consumers in a given system

Using this diagram of a simple system, demonstrate how carbon is conserved and not destroyed between states by dragging the flows (processes) to the correct boxes

Carbon dioxides (CO2) -> (Photosynthesis) -> Carbohydrates (CH2O) -> (Consumption) -> Sugar (C6H12O6) -> Cellular Respiration -> Carbon Dioxide (CO2)

For each statement below, decide whether it refers to photosynthesis or cellular respiration. Drag and drop the correct term next to the statement

Cellular respiration - a process that releases energy, a process that breaks the bonds of a sugar molecule, a process that is part of animal metabolism Photosynthesis - A process that produces a building block of carbohydrates, a process that requires the input of carbon dioxide, a process that requires energy input, a process that produces oxygen, a process that uses water

If chemical bonds did not exist, or were so strong that they never broke apart, there would be no movement of _________, which is required to break bonds, and is released when they are formed

energy