Some of the "branches" of a phylogenetic tree do not extend to the end. What do these lines represent?
A. Species of unknown origin
B. Extinct species
C. Lineages that have not changed
D. Convergent species
Answer: B
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Which of the following is false regarding agerelated
macular degeneration? a. It results in progressive destruction of photoreceptors in the fovea and surrounding region. b. It clouds the center of the visual field. c. It has no genetic basis. d. Smoking, high blood pressure, and obesity increase its risk. e. It cannot be cured, but its progression can be slowed.
Four of the five substances listed below are
cofactors or coenzymes. Select the exception. a. mineral b. water-soluble vitamin c. metallic ions d. NAD+ e. protein
Which one of the following statements is TRUE regarding the structure of a muscle?
A) The outer surface of a muscle is enclosed by many layers of epidermis. B) All muscle cells in a muscle have the same origin and insertion. C) Fascicles of a muscle are surrounded by a thin sheath of hyaline cartilage. D) Connective tissues associated with the muscle converge to form a ligament at each end of the muscle. E) Each fascicle consists of two muscle cells.
Which of the following statements about secretion is true?
(a) The membrane of a secretory vesicle will fuse with the plasma membrane when it discharges its contents to the cell's exterior. (b) Vesicles for regulated exocytosis will not bud off the trans Golgi network until the appropriate signal has been received bythe cell. (c) The signal sequences of proteins destined for constitutive exocytosis ensure their packaging into the correct vesicles. (d) Proteins destined for constitutive exocytosis aggregate as a result of the acidic pH of the trans Golgi network.