A microbial geneticist observes that a significant number of pyrimidine dimers are present in bacterial DNA following exposure to a particular mutagen. To which mutagen were the bacterial cells likely exposed?
A. UV light
B. X-rays
C. Acridine orange
D. 5-bromouracil
Answer: A
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Which of the following is not true of telomerase function?
A. Telomerase carries a 9-base DNA template complementary to 1.5 repeat units of the telomere sequence. B. One strand of the telomere sequence is elongated 6 bp at a time. C. The telomerase repeats its reaction many times in one telomere-binding event. D. The telomeres extended 3' end is made double-stranded by lagging strand synthesis. E. The RNA template is repositioned after each extension of the 3' end.
If the bacterium Staphylococcus aureus experiences a cost for maintaining one or more antibiotic-resistance genes, then what should happen in environments from which antibiotics are missing?
A. These genes should continue to be maintained in case the antibiotics ever appear. B. These bacteria should be outcompeted and replaced by bacteria that have lost these genes. C. The bacteria should start making and secreting their own antibiotics. D. The bacteria should try to make the cost worthwhile by locating, and migrating to, microenvironments where traces of antibiotics are present.
The process of fossilization typically begins when an organism or traces of it ____.
A. settle on the seafloor B. are pressurized under the weight of sediment C. crystallize into minerals D. are saturated with groundwater E. become covered with sediments, mud, or ash
The internal structure of eukaryotic cilia and flagella are the same
Indicate whether the statement is true or false