Some people have freckles and some people do not have freckles if a child has freckles at least one parent has freckles however the child may have a sibling that does not have freckles which statement best describes the presence of freckles. a : freckles are not determined by dna b: there are 2 alleles for freckles c: there is no dominant allele for freckles d: freckles are determined by 2 genes instead of by 1

1. an enzyme is considered a(n) because it speeds up a chemical reaction without being used up.2. in a catalyzed reaction, a reactant is often called a(n) . an enzyme is specific because the shape of its matches only particular reactants.4. an enzyme speeds up reactions by lowering the . the between an active site and its substrate often strains bonds and the reaction proceed.6. a( , which is often a vitamin, binds to an enzyme and plays a role in catalysis.7. high temperatures or changes in ph can an enzyme, causing it to lose its shape and biological activity.