Checkpoint area either tell the cell to go ahead and progress forward in the cell cycle, or stop because there is an issue of some kind.

Restriction enzymes are used in making recombinant dna. describe the role restriction enzymes perform when constructing recombinant dna.

How can a geological time scale best be reconstructed? a) comparing vestigial structures in living species b) comparing homologous structures in living species c) examining homologous structures in fossil remains d) examining the written records of scientists from past cultures

How have high taxes on tobacco products impacted the number of people who use them? a. the number of tobacco users has increased. b. the number of tobacco users has decreased. c. the number of tobacco users has not changed. d. the number of adolescent tobacco users decreased, while the number of adult users increased