SG 4

Question 1

Describe how our planet consists of many complex, large-scale, interacting systems. What patterns help us understand how our planet “works”?

Answer 1

They interact with and influence one another through the exchange of matter and energy.

A network of relations that interact- lithosphere, hydrosphere, biosphere, and atmosphere.

Question 2

Describe and give examples of negative and positive feedback loops. Which type of feedback stabilizes a system?
Which type is destabilizing? Which type is rare in nature but common in systems disturbed by human activities?

Answer 2

Pos. loops drive a system to extreme. Increase in output leads to increase in input, leading to further increase in output. Rare in nature. Nutrient overenrichment, blooms of algae, increased production of organic matter, decomposition, and hypoxia

Neg. loops create balance. The output of a system also acts as the input, driving the system in the opposite direction.

Question 3

Describe the structure and components of an atom. Distinguish between an isotope and an ion.

Answer 3

There are three parts of an atom: protons, neutron, and electrons. Protons have a positive charge, electrons have a negative charge, and neutrons possess no net charge.

Isotopes - Atoms of a given element with
differing numbers of neutrons

Ions - Atoms that gain or lose electrons and thus become electrically charged (+ or -)

Question 4

Distinguish between covalent, ionic, and hydrogen bonds. Which type of bond is the strongest?

Answer 4

Covalent bond = form when two or more atoms share the electrons in their outer shells H2O, CO2

Ionic bond = charged atoms held together by electrical attraction. Salts like NaCl

*Hydrogen bond = are the attraction formed between a slightly positively charged hydrogen atom and another
slightly negatively charged atom
-Account for the unique properties of water and the geometric shape of many biological molecules

Question 5

Describe the importance of water and be able to recognize its unique chemical properties.

Answer 5

Exhibits cohesion and adhesion.

Resists temperature changes.

Water as ice is less dense than liquid so floats.

Important in biological solutions and reactions.

Essential for life

Question 6

Define an acid and a base. Distinguish between acids and bases.

Answer 6

Base- property of a solution in which the concentration of hydroxide ions is greater than concentration of hydrogen. Bases—substances that either take up H+ or release OH-

Acids—substances that dissociate in H2O,
releasing H+

Question 7

Understand how hydrogen ions determine acidity. Be able to read a pH scale and recognize the pH of normal rainwater, seawater, and acid rain.

Answer 7

Acid rain- 4, normal rainwater- 5.5, seawater- >8

A pH of 7 is neutral. A pH less than 7 is acidic. A pH greater than 7 is basic.

Question 8

Distinguish between inorganic and organic compounds. What are hydrocarbons?

Answer 8

Hydrocarbons - consist solely of C and H. Simplest is methane gas. Crude oil is a complex mixture of 100s of them.

Question 9

Define energy and be able to distinguish between potential and kinetic energy. Recognize that chemical energy is a form of potential energy and describe how living and economics systems utilize this energy.

Answer 9

P: Stored energy. Water behind a dam.

K: Associated with motion. Water released from a dam.

Question 10

Give examples of energy transformations. Understand that they are usually not 100% efficient. Some energy is “lost” or “escapes” often in the form of heat.

Answer 10

Plant eats sun, cat eats plat, hawk eats cat.

Question 11

Describe the first and second laws of thermodynamics. How does burning firewood demonstrate an increase in entropy and the second law of thermodynamics?

Answer 11

The first law, also known as Law of Conservation of Energy, states that energy cannot be created or destroyed in an isolated system. Second law energy changes from a more-ordered to a less ordered state

entropy- an increasing state of disorder. living organisms resist entropy (get energy) dead organisms increase in entropy (no energy, decomposition)

increase in entropy burning firewood demonstrates the second law of thermodynamics. ex: potential energy (stored in the molecular bonds of wood) - kinetic energy (released as heat and light) - increase in entropy.

Question 12

Know that light energy from the sun powers most living systems.

Answer 12

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Question 13

What are autotrophs or producers? What are heterotrophs or consumers?

Answer 13

An organism capable of synthesizing its own food from inorganic substances using light or chemical energy. Green plants, algae, and certain bacteria are autotrophs.

An organism that cannot manufacture its own food and instead obtains its food and energy by taking in organic substances, usually plant or animal matter. All animals, protozoans, fungi, and most bacteria are heterotrophs.

Question 14

Describe and distinguish between the processes of photosynthesis and cellular respiration.

Answer 14

the process by which green plants and some other organisms use sunlight to synthesize foods from carbon dioxide and water. Photosynthesis in plants generally involves the green pigment chlorophyll and generates oxygen as a byproduct.

The term cellular respiration refers to the biochemical pathway by which cells release chemical energy from the chemical bonds of food molecules and provide that energy for the essential processes of life.

Question 15

Define ecosystem. Give examples of ecosystems.

Answer 15

A biological community of interacting organisms and their physical environment

Wetlands, forest, ocean

Question 16

Distinguish between gross primary production and net primary production. Recognize which ecosystems have the
lowest and greatest net primary productivity. How does cultivated land compared with natural ecosystems?

Answer 16

Gross primary production (GPP) is the total amount of energy produced by vegetation; some of that energy is used for cellular respiration i.e. for the growth and development of the plant.

Net primary production is the rate at which all the plants in an ecosystem produce net useful chemical energy; it is equal to the difference between the rate at which the plants in an ecosystem produce useful chemical energy (GPP) and the rate at which they use some of that energy during respiration.

NPP = GPP – cellular respiration

Secondary production
– Total biomass that heterotrophs
generate by consuming autotrophs

Question 17

Describe the cycling of the elements nitrogen, carbon, and phosphorus through the Earth’s systems. Recognize the
sources, sinks, or reservoirs involved in each cycle. Know which reservoirs are the largest. What is a flux rate?

Answer 17

Carbon Cycle - Producers pull carbon dioxide (CO2) from the air and use it in photosynthesis

Sedimentary rock is largest single reservoir and C can reside there for 100s of millions of years. Ocean is second.

Question 18

Describe how human activities have influenced the carbon, phosphorus, nitrogen, and water cycles. Describe the
evidence that demonstrates how these impacts can be minimized.

Answer 18

We mine for mineral and burn things- Getting them into the air and water causing eutrophication and damaging amphibians, increasing greenhouse gasses.

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Avoid phosphorus fertilizer, don’t burn anything, use organic toiletries

Question 19

Describe how “dead zones” have developed in aquatic ecosystems around the world. Describe the process of eutrophication? What are considered to be the key causes?

Answer 19

Excessive richness of nutrients in a lake or other body of water, frequently due to runoff from the land, which causes a dense growth of plant life and death of animal life from lack of oxygen.

Key cause- The most common nutrients causing eutrophication are nitrogen and phosphorus. The main source of nitrogen pollutants is run-off from agricultural land, whereas most phosphorus pollution comes from households and industry, including phosphorus-based detergents.

Question 20

biomass

Answer 20

the total mass of organisms in a given area or volume.

Question 21

cyanobacteria

Answer 21

Blue-green algae, which are more correctly known as cyanobacteria, are also frequently found in freshwater systems. A phylum of bacteria that obtain their energy through photosynthesis.