Chapter 3 Test Review

Chapter 3 Test Review - Dr. Marcum, Exploring Environmental...

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Dr. Marcum, Exploring Environmental Issues 1301 05 Chapter 3 study guide **Describe how positive and negative feedback loops work in nature Negative feedback loops = output resulting from a system moving in one  direction acts as an input that moves the system in other direction. Input and output essentially neutralize one another Example: body temperature and most systems in nature Positive feedback loops = instead of stabilizing  a system, it drives it further  toward one extreme or another Examples: exponential growth in human population, spread of cancer,  erosion. Rare in nature, but are common in natural systems altered by human  impact. Understanding requires system considerations Environmental entities are complex systems that work with each other.  For example, river systems consist of hundreds of smaller tributary  subsystems. The Gulf of Mexico from a system perspective Nutrients (nitrogen and phosphorus) from fertilizer enter the Mississippi  River from Midwestern US, which causes phytoplankton to grow, then  bacteria eat dead phytoplankton and wastes and deplete something,  causing aquatic organisms to suffocate.  **Describe the pH scale Acidic = less than 7.  Basic = greater than 7.  Neutral = equals 7.
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**Discuss the importance of proteins, DNA, carbohydrates, and lipids. They are essential to life.   Proteins: produce tissue, provide structural support, store and transport  energy, have long chains of amino acids, animals use proteins to generate  skin, hair, muscles, and tendons.  Some function as components of the  immune system, they can serve as enzymes molecules that promote  certain chemical reactions. DNA and RNA: carry the hereditary information of organisms.  Long 
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This note was uploaded on 05/05/2008 for the course ENV 1301 taught by Professor Larrylehr during the Spring '07 term at Baylor.

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Chapter 3 Test Review - Dr. Marcum, Exploring Environmental...

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