The metabolic reactions that occur in all cells require a certain molecule that was also believed to be present very early on Earth. What is this molecule?
a. nitrogen
b. carbon
c. water
d. oxygen
e. hydrocarbon
c
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Celiac disease is a condition in which the lining of the small intestine is damaged. Which of
the following is most affected by this disease?
a. villi b. gallbladder c. bile secretion d. salivary glands
Which of the following statements is false?
A) Some prophage genes can cause the transformation of a nonpathogenic bacterium into a form that causes human disease. B) Sometimes an environmental signal can trigger a switchover from the lysogenic to the lytic cycle. C) The lysogenic cycle always occurs inside of host cells. D) The lysogenic cycle typically results in the rapid lysis of all infected cells.
What could be a possible consequence if a structural gene's TATA box is mutated?
A. Unusable transcripts may be produced. B. The transcriptional start site may not function properly. C. Transcription may start at a variety of sites. D. The preinitiation complex may form at the wrong site. E. All of the choices are correct.
Which of the following is an advantage of the
three-chambered heart over the two-chambered heart?
a. blood flow is faster when there are two circuits instead of one circuit b. blood pressure is independently controlled in each vascular circuit c. oxygen-rich and oxygen-poor blood do not mix d. capillary beds are possible with a threechambered heart but not a two-chambered heart e. more than one of these is an advantage of the three-chambered heart over the twochambered heart