A ________ ring is the characteristic feature present in BOTH cephalosporins and penicillins produced by fungi. Semisynthetic versions of these drugs typically ________ this ring structure with other functional groups
a. ?-lactam / add to
b. ?-lactam / replace
c. lactone / add to
d. lactone / replace
Answer: A
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The key point in Darwin's proposal is that the ___________ imposes the conditions that determine the direction of selection.
A. gene B. environment C. parent D. individual
Members of the genus Thermomonospora
A. can be isolated in compost piles and hay. B. produce single spores on their mycelia. C. spores can form on either aerial or substrate mycelia. D. All of the choices are correct.
The surface of a Paramecium is covered with thousands of short, hair-like ____
a. plasmadesmata b. pseudopods c. trichomes d. flagella e. cilia
In Drosophila, dosage compensation is controlled by the male-specific lethal (MSL) complex consisting of MSL proteins and roX RNAs. Based on what you know about dosage compensation, the role of the MSL complex in males would be to
A. decrease the level of expression of genes on the X chromosome by 100%. B. increase the level of expression of genes on the X chromosome by 50%. C. double the level of expression of genes on the Y chromosome. D. decrease the level of expression of genes on the X chromosome by 50%. E. double the level of expression of genes on the X chromosome.