Exploring how organisms get and use energy.

  • How Do Living Things Get Energy?

    Energy flows through all living things and the environment. Some energy is stored and much is lost into the environment as heat. Food webs, food chains and energy pyramids are used to represent energy flow.

  • Where Does Energy Go?

    Cells and organisms get and give off energy in a variety of ways: photosynthesis, chemosynthesis, cellular respiration and fermentation.

  • What Do We Need to Eat?

    Living organisms use matter and energy to create a wide variety of organic molecules (e.g., proteins, carbohydrates, lipids and nucleic acids) and to allow life to happen in growth, reacting to the environment, reproduction and movement. Ecosystems also recycle many materials, such as water, carbon and nitrogen.

  • How Does Energy Affect the Inside of the Earth?

    Explain how conduction, convection and radiation influence the movement of different layers of the Earth, resulting in volcanoes, earthquakes, mountain building, and other results of plate tectonics.

OGT Questions:

  1. The pesticide DDT was at one time referred to as a “miracle” pesticide. Its widespread use in the United States peaked in 1959, but then usage steadily declined until its ban in late 1972. Reasons for declining usage included increased insect resistance and public concern over potentially harmful environmental effects.

    How did this concern affect the field of agricultural science?

    1. It led to the development of equally harmful herbicides.
    2. It encouraged farmers to violate the ban and increase the use of DDT.
    3. It led to the development of more effective, alternative pesticides.
    4. It encouraged farmers to reduce the number of crops grown in their fields.
  2. Energy produced by cellular processes is stored as

    1. CO2.
    2. ATP.
    3. DNA.
    4. RNA.
  3. In 1864, Louis Pasteur was asked to investigate diseases afflicting the wine in Arbois, France. He discovered that these diseases were caused by micro-organisms that could be killed by heating the wine to 55C for a period of time.

    What is this process called today that applies to milk?

    1. homeostasis
    2. fermentation
    3. differentiation
    4. pasteurization
  4. A simple food chain in a wetland is represented below.

    1. migration of blue herons out of the wetland area
    2. introduction of a predator that feeds on blue heron eggs
    3. application of insecticides to wet areas where mosquitoes breed
    4. implementation of new conservation laws to protect the wetland

    An ecologist doing population counts in the wetland observes a drop in the number of trout over an extended period of time.

    What change is most likely responsible for the trout decline?

  5. Environmental monitoring of a lake located to the southeast of a factory has shown a consistent decrease in pH over the period of a year. A researcher investigating the pH change hypothesizes that either a factory or a farm along the river is responsible for the pH change. The river flows into the lake.
    The researcher collects a water sample from locations Y and Z in the diagram and runs pH analyses on each sample. He finds that the pH in sample Z is lower than the pH in sample Y and concludes that the factory is responsible for the low pH values in the lake.

    Based on the diagram and the researcher’s investigation, provide two reasons why this may not be a valid conclusion. Describe how each reason could invalidate the conclusion.

    Respond in the space provided in your Answer Document. (4 points)