What is the main idea behind the model of a molecular clock?
a. that neutral mutations accumulate at a steady rate
b. that certain traits are under the pressure of natural selection
c. that segments of DNA can be compared with segments of RNA
d. that phenotypes, not genotypes, are affected by natural selection

What mistake did john needham make that caused him to conclude that spontaneous generation for microorganisms occurred? a. he re-contaminated his boiled broth solutions. b. he destroyed the vital force in the solutions. c. he did not boil his broth solutions, only warmed them. d. he failed to seal his flasks of boiled broth. e. he allowed his assistant to conduct the experiment which he did not monitor closely.