Na is made of nucleotides which are composed of a. a phosphate group, a sugar group and a nitrogenous base. b. a sugar group, an amino acid group and a nitrogenous base. c. a phosphate group, a starch group and a nitrogenous base. d. a protein group, a sugar group and a nitrogenous base.

Development of new communities in disturbed environments, such as a burned or a clear cut forest, is called

Explain how sequences of amino acids in proteins can be used to reveal relationships among organisms.

Lactase is essential for digesting lactose in milk. this enzyme is specific for this sugar. why? molecules and active sites vary in size; only properly sized molecules can fit.there is a precise compatibility between the active site and the lactose molecule.specificity refers to the action of the enzyme, such as hydrolysis, and relatively few molecules can be hydrolyzed.reaction-specific enzymes assume a fit by folding around the most numerous substrate molecules.