Which of these would most likely change the number of chromosomes found in a cell? A. A pair of chromosomes does not separate when a cell divides. B. A set of chromosomes is duplicated when a cell divides by mitosis.
C. A chromosome in a cell has a sequence of bases altered by a mutation.
D. A pair of chromosomes in a cell overlaps and exchanges genes during meiosis.

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.