It is hypothesized that RNA may have evolved before DNA because RNA molecules A. were the first molecules synthesized by Miller and Urey
B. are more important to genetic inheritance than DNA
C. can catalyze a variety of biologically important reactions
D. are found in more modern cells than are DNA molecules

In an experiment examining the effects tai chi on arthritis pain, callahan (2010) selected a large sample of individuals with doctor-diagnosed arthritis. half of the participants immediately began a tai chi course and the other half (the control group) waited 8 weeks before beginning. at the end of 8 weeks, the individuals who had experienced tai chi had less arthritis pain that those who had not participated in the course.

Atest cross can be used to -predict the phenotypes of a monohybrid cross -predict an unknown genotype of a purebred dominant plant -cross-breed dominant and recessive plants -give probabilities that a trait will appear

In the sentence "a mining company will consider the distribution of coal when deciding how to mine the coal," what does the word distribution mean?