What must happen before a chemical reaction can begin? a. the activation energy must be exceeded b. the activation energy must be reached c. the concentrations of products and reactants must be equal d. the concentration of reactant molecules must be reduced

Which statement best explains how cellular respiration maintain homeostasis in animals? it maintains body temperature by absorbing energy. it breaks glucose into energy required by the organism. it speeds up metabolism by making oxygen. it produces energy from hormones present in the organism.

How are the tortoises that darwin observed on the galápagos islands similar to the anoles that losos studied

What is a gene ? a) a section of a protein that codes for dna. b) the alternate version of a trait. c) the visible trait in the f1 generation. d) a section of dna that codes for a specific trait .