Represented by only two living genera, Psilotum and Tmesipteris, ____ resemble the extinct Cooksonia. Having no
true roots or leaves, these seedless vascular plants are essentially forking green stems.
a. mosses
b. whisk ferns
c. ferns
d. club mosses
e. horsetails
ANSWER: b
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A patient who is positive for the human immunodeficiency virus (HIV) is diagnosed with a Cryptococcus neoformans infection. The attending resident prescribed Griseofulvin; however, the patient's condition did not seem to improve. Which one of the following statements explains this discrepancy?
a. The dose should be increased to penetrate the blood-brain barrier. b. Nystatin, which would have been more effective, should have been prescribed. c. Griseofulvin is not effective against C. neoformans; therefore the therapy should be changed. d. Potassium iodide is the therapy of choice, not griseofulvin.
Adenoviruses are a frequent cause of acute upper respiratory tract infections in humans. Adenoviruses have a genome composed of double-stranded DNA; they are non-enveloped and their capsid contains a "fiber" protein that is analogous in function to the spike glycoproteins of HIV. Latency of the adenovirus can occur in lymphoid tissues. Based on this information, which of the following would be the best type of drug to develop to combat adenoviruses in humans?
A. a drug that inhibits reverse transcriptase B. a drug that binds to fiber protein receptors in human cells C. a drug that can switch off latency D. a combination of drugs that inhibit reverse transcriptase and that binds to fiber protein receptors in human cells E. a combination of drugs that inhibit reverse transcriptase, binds to fiber protein receptors in human cells, and switches off latency
Indicate the statements that are true about carnivorous plants: (check all that apply)
_____ Carnivorous plants fix their own nitrogen. _____ Carnivorous plants with active trapping mechanisms are often stimulated by wind. _____ Carnivorous plants are likely to be green. _____ Some carnivorous plants engage in symbioses. _____ Some carnivorous plants produce substances that enhance their ability to attract prey.
DNA codes for the production of
a. proteins. b. minerals. c. inorganic molecules. d. vital gasses. e. water.