2.  Food chains, food webs, and energy pyramids are all ways to show the flow of energy through different organisms in an ecosystem.  Energy comes from the sun to producers then move up through consumers and end with the apex predators or decomposers.

3.  Make up living things.  C-goes-SHOPN (Non-metals)  Carbon, Sulfur, Hydrogen, Oxygen, Phosphorus, and Nitrogen.

4.  Both physical and chemical changes happen during the digestive system process.  Examples:  Physical- chewing your food in your moth to break it down into smaller pieces.  Chemical- enzymes break down food molecularly to be absorbed into the blood stream.

5.  If you lift a box straight up and place it on a table, or use a ramp to push the box up to the table the same amount of work is being done.  W=Fxd  If no movement occurs then no work is done because no distance is covered.

6.  Human activities can affect groundwater (aquifers) and surface water (lakes, ponds) in a negative way by pollution. Water sources are linked together by the water cycle. If you pollute one source you can potentially pollute them all.  Examples:  Humans cause more watershed into surface and underground water systems which pollutes them with human trash, wastes, fertilizers, and pesticides.  Also humans can over-use water causing water shortages.

7.  Biodiversity contributes to the sustainability of an ecosystem because there is more organisms in the ecosystem to help balance the ecosystem.

8.  There are two types of ecological succession that can occur after a catastrophic event:  Primary Succession -ecosystem starts with no soil in place for producers to grow. Pioneer species must create soil over time. (occurs after volcanos or glaciers).  Secondary Succession – after the natural disaster or ecological disturbance, soil is left where producers can grow. (forest fires, an overgrown garden microhabitat).

9.  A Dichotomous key is used to identify organisms based on their physical structures.

10.  Natural selection is the process by which organisms that can adapt to changes in their environment are able to survive and reproduce. (Nature controls which organisms survive).  Ex-Galapagos Islands Finches.(Darwin)  Selective breeding is the intentional reproduction of specific organisms in an attempt to produce offspring with desirable characteristics. (Controlled by humans).  Ex- Race horses  Ex- Crops  Ex- Chickens/Cows

11.  Circulatory system- The system of blood, blood vessels, and heart that is responsible for circulation/transportation of nutrients, oxygen, and wastes.  Respiratory system- The system of organs functioning in respiration and gas exchange in the lungs. (Oxygen and Carbon dioxide).  Skeletal system- The framework of the body, consisting of bones, which protects and supports the body tissues and internal organs.

12.  Muscular system- controls movement in the body.  Digestive system- The system by which ingested food is acted upon by physical and chemical means to provide the body with nutrients.  Excretory system- The system that excrete wastes from the body.  Reproductive system- The male or female organs that allow an organisms to reproduce.  Integumentary system- covers and protects; Outer layer of the body.

13.  Nervous system- The system of nerves, brain, and spinal cord. Responsible for communication throughout the body.  Endocrine system- consists of the endocrine glands and the hormones they secrete. Regulates growth and reproduction.

15.  According to the cell theory all organisms are composed of cells and cells carry on similar functions such as extracting energy from food to sustain life. Cell theory: 1. Cell is basic unit of life. 2. Cells come from pre- existing cells. 3. Organisms are made up of one or more cells.

16.  Cell membrane- Outer layer of the cell that lets things in and out of the cell.  Ribosomes- create proteins that make DNA.  Nucleus- Control center of the cell.  Vacuoles- used for storage.  Mitochondria- powerhouse of the cell (Energy).  Lysosomes- They break down waste and food and are known as the stomach of the cell.  Cell Wall- The ridged and strong outer layer of a plant cell.  Chloroplasts- Where photosynthesis (makes glucose) takes place in a plant cell.

17.  Sexual reproduction requires two parents to create the offspring, DNA of the offspring is diverse.  Asexual reproduction requires only one parent to create the offspring, which means that the offspring will be uniform to the parent.

18.  Inherited traits of individuals are governed in the genetic material found in the genes within chromosomes and the nucleus.