| A | B | 
| Macromolecules | carbohydrates, lipids, proteins, and | 
| Mechanism | The combination of components and processes that serve a common function | 
| Meiosis | two‐phase nuclear division that results in the eventual production of gametes | 
| Migration (Genetics) | permanent movement of genes into or out of a population resulting in a change in allele frequencies | 
| Mitochondrion | organelle found in eukaryotes; site of cellular respiration | 
| Mitosis | nuclear division resulting in the production of two somatic cells having the same genetic makeup | 
| Molecule | smallest particle of a substance that retains the chemical and physical properties of the substance | 
| Monomer | molecule of any compound that can react with other molecules of the same or different compound to form a polymer | 
| Multicellular | Made up of more than one cell | 
| Multiple Alleles | More than two forms of a gene controlling the expression of a trait | 
| Mutation | permanent transmissible change of genetic material | 
| Natural Selection | process in nature in which organisms possessing certain inherited traits are better able to survive and reproduce | 
| Nondisjunction | The process in which sister chromatids fail to separate during and after mitosis or meiosis | 
| Nonnative Species | species normally living outside a distribution range that has been introduced | 
| Nucleic Acid | A biological macromolecule (DNA or RNA) composed of the elements C, H, N, O, and P that carries genetic information | 
| Nucleus | organelle that holds the genetic material and controls cell functions |