9. Which of the following processes involves the net movement of water across a selectively permeable membrane?
(A) Active transport
(B) Facilitated diffusion
(C) Osmosis
(D) Cotransport

5. A single polypeptide chain can have all of the following levels of structure EXCEPT:(A) Primary structure (B) Secondary structure (C) Tertiary structure (D) Quaternary structure

6. Which of the following is present in a prokaryotic cell?(A) Mitochondrion (B) Ribosome (C) Nuclear envelope (D) Chloroplast

7. For a resting neuron, which of the following is true regarding ion distribution and membrane potential?(A) The concentration of Na+ is higher inside the cell, and the membrane potential is positive.(B) The concentration of K+ is higher outside the cell, and the membrane potential is positive.(C) The concentration of Na+ is higher outside the cell, and the inside is negatively charged relative to the outside.(D) The concentration of K+ is higher outside the cell, and the inside is positively charged relative to the outside.

8. Which of the following classes of large biological molecules does NOT consist of polymers?(A) Carbohydrates (B) Proteins (C) Lipids (D) Nucleic acids

10. To study the process of protein translation from mRNA, which cellular component would be most enriched in the finalpellet after cell fractionation?(A) Nuclei (B) Mitochondria(C) Pieces of plasma membranes (D) Ribosomes

11. Consider a metabolic pathway where compound X is converted to Y, and Y is converted to Z. If the enzyme converting X to Y is inhibited by the accumulation of Z, this is an example of:(A) Allosteric activation. (B) Competitive inhibition.(C) Noncompetitive inhibition. (D) Feedback inhibition.

12. An enzyme is added to a solution where its substrate and product are in equilibrium. What will occur?(A) Additional substrate will be formed.(B) The reaction will change from endergonic to exergonic.(C) The free energy of the system will change.(D) Nothing; the reaction will stay at equilibrium.

13. What percentage of the human genome codes for proteins or gives rise to rRNAs or tRNAs?(A) 1.5% (B) 5% (C) 20% (D) 75%

14. The immediate energy source that directly drives ATP synthesis by ATP synthase during oxidative phosphorylation is the:(A) oxidation of glucose and other organic compounds.(B) flow of electrons down the electron transport chain.(C) H+ concentration gradient across the membrane holding ATP synthase.(D) transfer of phosphate to ADP.

15. How do transposons and retrotransposons differ in their movement mechanisms within the genome?(A) Transposons move via an RNA intermediate, while retrotransposons move via a DNA intermediate.(B) Transposons are less prevalent and move via an RNA intermediate, while retrotransposons are more prevalent and move via a DNA intermediate.(C) Transposons move via a DNA intermediate, while retrotransposons are more prevalent and move via an RNA intermediate.(D) Both transposons and retrotransposons move via a DNA intermediate, but only retrotransposons create new copies.