BIO 181 Exam# 1 (Chapters 1, 2, 3, 4 and Labs 1, 2, 3) well answered

BIO 181 Exam# 1 (Chapters 1, 2, 3, 4 and Labs 1, 2, 3)Describe the six characteristics of all living organisms. - correct answer Cellular Organization: made up of cells Ordered Complexity: very complex Sensitivity: responds to environment Growth, Development, and Reproduction: Energy Utilization: make energy and convert to usable Homeostasis: maintain internal factors at a steady rate Evolutionary Adaption: changes based on environment Define hypothesis. Describe two traits that a good hypothesis has. - correct answer A hypothesis is a possible explanation for an observation. Hypothesis must be able to be tested and allow predictions to be made. What is the difference between a test experiment and a control experiment? Why is a control experiment so important? - correct answer A test experiment has a variable that changed and the control experiment is the same experiment with nothing changed. The control experiment is necessary because it is needed to show that the variable is the reason for the result. When does a hypothesis become a theory? - correct answer A hypothesis becomes a theory when it has been tested multiple times over a long period of time that yields the same results throughout. Describe the three components that make up the structure of an atom. Make sure that you discuss the location and charge of the components. - correct answer The three component that make up an atom are protons, electrons, and neutrons. Protons are located in the nucleus and have a positive charge. Neutrons are also located in the nucleus and are neutral in charge. Both the protons and the neutrons have a mass of approximately 1 Dalton. Electrons are located in the orbitals and have a negative charge. The electrons have no mass. What is the difference between mass and weight? - correct answer Mass is the amount of a substance and Weight is the force gravity exerts upon substance. Define the terms oxidation and reduction. - correct answer Oxidation is the loss of an electron and Reduction is the gaining of an electron. These happen in chemical reactions. Sodium has 11 electrons. How many electrons are in its valence electron shell. Does this satisfy the octet rule? If not, what can sodium do to satisfy the octet rule? - correct answer Sodium has 1 electron in its valence electron shell. This does not satisfy the octet rule. To satisfy the octet rule sodium can lose an electron and become a ion (Na+). Why is water considered a polar molecule? Make sure that you use the work electronegativity in your answer. - correct answer Water is a polar molecule because oxygen has a higher electronegativity than Hydrogen which means that the electrons are pulled more to oxygen and away from Hydrogen. This leads to a slightly negative oxygen and a slightly positive hydrogen and an unequal sharing of electrons. Is this a true chemical reaction? If not, explain why it couldn't happen. 6H2O + 6CO2 → C6H12O6 + 5O2 - correct answer This is not a true chemical reaction because the reactants have 18 oxygen and the products only have 16 oxygen. For the chemical reaction to be true, the reactants and products must have the same number of atoms on each side to balance the equation. Describe the three factors that influence the rate of chemical reactions. - correct answer Three factors that influence the rate of chemical reactions are temperature, concentration of reactants and products, and catalysts. The higher the temperature of the chemical reaction is the faster it goes. The higher concentration of reactants and products increases the rate of chemical reaction. Catalysts are enzymes designed to increase the rate of reaction. Why is it important biologically that water has a high specific heat? - correct answer It is important biologically that water has a high specific heat because a lot of reactions happen in the body which gives off a lot of heat but because it happens in a watery environment the temperature of the body is able to stay a steady rate. If you add a strong acid like HCl to water it dissociates into H+ and Cl-. How does this affect the acidity of the solution? How does this affect the pH of the solution? - correct answer This affects the acidity of