During which period of the Paleozoic era did the first winged insects evolve?
A.Carboniferous
B. Devonian
C. Permian
D. Ordovician
E. Cambrian
A. Carboniferous
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A new experimental pesticide is being tested by a large agricultural chemical company. An unfortunate side effect in plants treated with this new product is a partial inhibition of ferredoxin-NADP+ reductase in the chloroplasts
Given this observation, what specific change(s), if any, would you expect to observe in the amounts of NADPH, ATP, 3- phosphoglycerate and glyceraldehyde-3-phosphate, and RuBP in the chloroplasts of these plants? What will be an ideal response?
When nitrate is reduced to dinitrogen gas (N2), nitrogen is removed from the ecosystem and returned to the atmosphere through a series of reactions collectively known as ________.
A. denitrification B. nitrogen fixation C. anammox reaction D. All of the choices are correct.
Gentamicin, streptomycin, tetracycline, clindamycin, and erythromycin are _______.
A. examples of antibiotics that inhibit protein synthesis B. examples of beta-lactamase susceptible antibiotics C. examples of aminoglycosides D. examples of antibiotics that are associated with a high incidence of liver toxicity
A woman with severe acne wishes to go on Accutane even though she is pregnant. Based on this drug's critical period, when would be a reasonably safe time for her to do so?
A) When she first becomes pregnant B) After her first month of pregnancy C) After her second month of pregnancy D) After her fourth month of pregnancy