How does a catalyst work?
by increasing the temperature of a chemical reaction
by decreasing the pressure of a chemical reaction
by increasing the concentration of reactants in a reaction
by decreasing the activation energy of a reaction

About __ of the mass of the cell is water

As the earth formed, the force of gravity increased due to increased mass. what effect did this increased gravity have on the forming planet?

Transposon can cause mutations in genes at or near the site of transposon insertion. it is possible for these elements to transpose away from their original site, causing a reversion of the mutant phenotype. in some cases, however, even more severe phenotypes appear when these elements excise from this site, due to events at or near the mutant allele. what might be happening to the transposon or the nearby gene to create more severe mutations?