The bark of the pacific yew tree (taxus brevifolia) was the original source of one of the most effective drugs for treating tumors of the breast, lung, and other sites. taxol, a chemical extracted from this bark, kills actively replicating cells by inhibiting the depolymerization of microtubules. why are microtubules good targets for killing cancerous cells

Punctuated equilibrium verses gradualism have long been contested as ways in which species evolve. choose the best evidence for gradualism.

The activity of the modern sample is 1.10 bq . how long does that measurement take?

Which of these is true of the cytoplasm of an unfertilized egg? a. it is an unevenly distributed mixture of mrna, proteins, organelles, and other substances. b. it does not contain substances that are important in directing development. c. these substances are supplied by the sperm. d. it does not contain substances that are important in directing development. e. development is directed solely by the surrounding cells. f. it is a homogeneous mixture of mrna, proteins, organelles, and other substances. g. it does not contain substances that are important in directing development. h. these substances are produced by the dna of the fertilized zygote.