ISB 201 1st EditionExam # 3 Study Guide Lectures: 11-16Lecture 11 (February 25)SoilHow did the Hawaiian Islands become lush and green?Soil is a complex ecosystem of living and non-living things that occur on the land surface and characterized by ability to support rooted plants.The Islands began as a chain of volcanoes that formed as the pacific plate moved over a hot spot in the Pacific Ocean. First just mounds of lava and ash, soil formed through the breakdown of rocks (decomposers and fungus) and algae growth which makes its own food. Lichens attach to rock surface and secrete chemicals that break down rock. Fungus and algae begin to form in crevices and as they die, decompose to create soil. Then, deep rooted plants can colonize and the island becomes green with life.Why is the Grayling no longer a species of fish in Michigan Rivers?As loggers cut down mass amounts of trees along river banks, it caused the breakdown of rock and living material or erosion that fell into the rivers. Soil filled rivers, destroying the Grayling’s ecosystem. What are the three components of healthy soil and give an example of each. A healthy ecosystem needs fresh water and healthy soil. Healthy soil contains nutrients, minerals, and texture.Nutrients: organic, decomposition of plants and animals. This consists of macronutrients that are needed in large amounts, such as Nitrogen and Phosphorous, and micronutrients that are need in smaller amounts like Iodine. Minerals: come from rocks and are inorganic. Texture: the percentage of silt, clay, and sand in soil and the ability to hold and store water. Lecture 12 (March 2) Describe the difference between selective breeding and genetic modification? How can these be beneficial for farming? What is one problem that could arise with each?Selective breeding is developing plants or animals based on selecting desirable characteristics ofthe parents. This is how corn that we eat today was created. A possible problem is that plants natural defenses can be modified like that of the milkweed plant. Genetic modification is more invasive. It involves taking genetic information from one organism and introducing in to a different organism. GMO’s are used in agriculture to produce bigger crops, prevent against pests, and even to notify farmers when crops need water. This is highly controversial because of possible health threats. How do insects become resistant to pesticides? What is the pesticide treadmill and use an insect in you explanation. We will never beat insects because their high biotic potential causes high genetic variability leaves insects to reproduce and survivors build up immunity. The pesticide treadmill explains how insets build up resistance which causes famers to use moreand more pesticides. Insects respond by building up even more of a resistance which then causes more and more pesticides in the environment. This is seen with aphids that became resistant to DDT and other pesticides. Because of this, biological control was uses along with pesticides to protect crops. Lecture 13 (March 4)How is water both a renewable and non-renewable resource?Water is renewable because it never really goes away. There will always be the same amount of water on Earth. However, water is being considered non-renewable because the quality of water has been compromised by human activity. We can no longer use all of it so we have a limited supply. What are similarities and differences between the natural water cycle and the urban water cycle?The natural and urban water cycles have the same steps of condensation, infiltration, ground water flow to a water body, and evaporation. Infiltration is far less for the urban water cycle because it is an impermeable surface. This causes more runoff into streams rather than in bedrock. Water has to be recycled at the surface level. Lecture 14 (March 16)What is the difference between oligotrophic and eutrophic water bodies? Provide 2 examples of human activity that can create a eutrophic water body?Oligotrophic: Clear blue water, deep, less sediment, pine trees, water colder (less decomposition and higher oxygen levels)Eutrophic: sediment build up, shallow, trees that drop leaves, plants dominate shore line and aquatic vegetation, murky water, warmer (less oxygen)Humans add excessive nutrients by using fertilizers, laundry detergents and soaps that contain high phosphorous and nitrogen levels. Human and animal wastes also contribute to eutrophic water bodies if they feed into a natural stream or local water source. Lecture 15 (March 18)Describe the steps that contribute to the Gulf of Mexico dead zone.1. Nutrients from farms, neighborhoods, and cities in the Great Plains and corn-belt run offinto nearby rivers and streams. 2. These nutrients enter the Mississippi River watershed that drains into the Gulf of Mexico.3. The excess levels of nitrogen and phosphorous cause free floating phytoplankton to reproduce at rapid rates as the nutrients float on the surface.4. Phytoplanktons block sunlight from the benthic plants, discouraging them from producing oxygen and causing many to die.5. Aerobic bacteria reproduce quickly in response to the mass increase of dead and decaying material at the bottom of the Gulf from lack of Oxygen. They use of the remainder of the oxygen creating a Hypoxic or low-oxygen area. Lecture 16 (March 23) What is the difference between a point-source of pollution and a non-point source?Point-source: associated with big business and industry directly dumping waste into a water body through a drainage pipe. Cattle feed lots are now considered one too. Non-point source: accumulated effects of everyone; cannot pin-point exact source. This makes itvery difficult to regulate and manage. What are the three components of pollution and give two example of each. Water pollution is the physical, chemical, or biological change in water quality. It has harmful effects on living organisms or makes water unsuitable for use. Physical: sediment, suspended matter, heatBiological: E.coli, invasive speciesChemical: oil, heavy metal,