8. Rank, from low to high, the pH of blood, stomach acid, and urine.
(A)blood, urine, and stomach acid
(B)stomach acid, blood, and urine
(C)urine, blood, stomach acid
(D) stomach acid, urine, blood

4. Following a scientific method, which of the following is the correct order of steps?(A)Observation → Analysis → Hypothesis → Conclusion → Communicate results → Experiment(B)Observation → Hypothesis → Experiment → Communicate results → Analysis → Conclusion(C)Experiment → Hypothesis → Observation → Analysis → Conclusion → Communicate results(D) Observation → Hypothesis → Experiment → Analysis → Conclusion → Communicate results

5. Which of the following are compounds? (A)H2O, O2, and CH4 (B)H2O and O2 (C)O2 and CH4 (D) H2O and CH4, but not O2

6. Molybdenum has an atomic number of 42. Several common isotopes exist, with mass numbers from 92-100. Which of the following can be true? (A)Molybdenum atoms can have between 50 and 58 neutrons. (B)Molybdenum atoms can have between 50 and 58 protons. (C)Molybdenum atoms can have between 50 and 58 electrons. (D) Isotopes of molybdenum have different numbers of electrons.

7. The cities of Portland, Oregon, and Minneapolis, Minnesota, are at about the same latitude, but Minneapolis has much hotter summers and much colder winters than Portland. Why? (A)They are not at the same exact latitude. (B)The ocean near Portland moderates the temperature. (C)Fresh water is more likely to freeze than salt water. (D) Minneapolis is much windier, due to its location in the middle of North America.

9. How would acidification of seawater affect marine organisms? Acidification of seawater would (A)increase dissolved carbonate concentrations and promote faster growth of corals and shell-building animals (B)decrease dissolved carbonate concentrations and promote faster growth of corals and shell-building animals (C)increase dissolved carbonate concentrations and hinder growth of corals and shell-building animals (D) decrease dissolved carbonate concentrations and hinder growth of corals and shell-building animals

10. Which of the following statements correctly describes cis-trans isomers?(A)They have variations in arrangement around a double bond.(B)They have an asymmetric carbon that makes them mirror images.(C)They have the same chemical properties.(D) They have different molecular formulas.

11. What is the explanation for how a modern transmission electron microscope (TEM) can achieve a resolution of about 0.2 nanometers, whereas a standard light microscope has a maximum resolution of about 200 nanometers? (A)Glass lenses in light microscopes refract light, which reduces resolution. (B)Contrast is enhanced by staining with atoms of heavy metal. (C)Electron beams have much shorter wavelengths than visible light. (D) The electron microscope has a much greater ratio of image size to real size.

12. Tay-Sachs disease is a human genetic abnormality that results in cells accumulating and becoming clogged with very large, complex, undigested lipids. Which cellular organelle is most likely defective in this condition? (A)the lysosome (B)the Golgi apparatus (C)the smooth endoplasmic reticulum (D) the rough endoplasmic reticulum

13. If plant cells are grown on media containing radioactively labeled thymine for one generation, radioactively labeled macromolecules will be detected in which of the following? (A)only in the nucleus (B)only in the nucleus and mitochondria (C)only in the nucleus and chloroplasts (D) in the nucleus, mitochondria, and chloroplasts

14. Most cells cannot harness heat to perform work because_________.(A)heat is not a form of energy(B)temperature is usually uniform throughout a cell(C)heat can never be used to do work(D) heat must remain constant during work