Energy of activation . a. is the energy required for molecules to react with each other b. requires the use of enzymes c. allows for feedback inhibition d. acts on the products of metabolic reactions

a. is the energy required for molecules to react with each other

Explanation:

Activation energy may be defined as the extra energy required to start a reaction and the conversion of reactants into its products. It is the energy required to energize or activate molecules or atoms to undergo a transformation or a chemical reaction.

It is necessary for all types of chemical reaction to proceed. With the help of a catalyst the reaction rate increases as the energy of activation lower for the reaction to start.

answer; i believe the correct answer is (replication is not conservative);

answer : haversian

[explanation: -(compact bone is organized as parallel columns, known as haversian systems, which run lengthwise down the axis of long bones. these columns are composed of lamellae, concentric rings of bone, surrounding a central channel, or haversian canal, that contains the nerves, blood vessels, and lymphatic system of the bone)]