3. Which of the following statements best describes how unsaturated fatty acids increase membrane fluidity at lower temperatures?
(A) The double bonds form kinks in the fatty acid tails, preventing adjacent lipids from packing tightly.
(B) Unsaturated fatty acids have a higher cholesterol content, which prevents adjacent lipids from packing tightly.
(C) Unsaturated fatty acids are more nonpolar than saturated fatty acids.
(D) The double bonds block interaction among the hydrophilic head groups of the lipids.

39. The term "synapse" has been used to describe the contact points between: (1) neuronal cells. (2) immune cells. (3) epithelial cells. (A) (1) (B) (2) (C) (3) (D) None of above (E) All of the above

40. Which of the following statement about myelination is incorrect? (A) Myelination is required in both the CNS (central nervous system) and PNS (peripheral nervous system). (B) Myelination involves the ensheathment and insulation of axons by radial glial cell membranes. (C) Myelinating Schwann cells extend their processes to wrap up axons at a 1:1 relationship. (D) Myelinating Oligodendrocytes extend multiple processes that will contact and myelinate several axons. (E) None of above is incorrect.

1. A newly synthesized protein destined for secretion from a eukaryotic cell will generally follow which of the pathways listed below? (A) rough ER → Golgi → transport vesicle → nucleus (B) Golgi → rough ER → lysosome → transport vesicle → plasma membrane (C) rough ER → Golgi → transport vesicle → plasma membrane (D) rough ER → lysosome → transport vesicle → plasma membrane

2. Which of the following structures form cytoplasmic channels that connect adjacent plant cells through the cell walls? (A) desmosomes (B) gap junctions (C) plasmodesmata (D) tight junctions

複選題4. Which of the following responses is stimulated by cell signaling the formation of biofilms? (A) formation of mating complexes (B) aggregation of bacteria (C) secretion of substances that inhibit the growth of foreign bacteria (D) inhibition of quorum sensing

5. Upon completion of the citric acid cycle, most of the energy originally stored in each glucose molecule catabolized by cellular respiration is stored in which of the following molecules? (A) acetyl-CoA (B) ATP (C) CO2 (D) NADH

6. On a spaceship designed to support a multiyear voyage to the outer planets of the solar system, plants will be grown to provide oxygen and to recycle carbon dioxide. Because the spaceship will be so far from the sun, an artificial light source will be needed to support photosynthesis. Which of the following wavelengths of light should be used to maximize plant growth? (A) a mixture of yellow and orange light (B) green light (C) a mixture of blue and red light (D) ultraviolet light

7. Which of the following statements describes a characteristic feature of metaphase? (A) alignment of chromosomes on the equator of the cell (B) separation of the centromeres (C) cytokinesis (D) separation of sister chromatids

8. How many unique gametes could be produced through independent assortment by an individual with the genotype AaBbCCDdEE? (A) 4 (B) 8 (C) 16 (D) 64

9. Use the following information to answer the question. In the figure, the letters A-G represent individual species that all descended from a common ancestor. Which of the following groups of these species forms a monophyletic group? (A) A, B, C, D (B) C and D (C) D, E, and F (D) E, F, and G