focus – n. a main purpose or interest

genetic code – biology n. the arrangement of chemical groups within the genes which specify particular kinds of amino acids used to make proteins

instruction – n. an order or command

immune response – medical n. a bodily response to an antigen that occurs when lymphocytes identify the antigenic molecule as foreign and induce the formation of antibodies and lymphocytes capable of reacting with it and rendering it harmless

birth defect – n. a physical or biochemical defect that is present at birth and may be inherited or environmentally induced

delivery – n. the transfer of something from one place or person to another

mutation – n. a change in a gene or the resulting new trait it produces in an individual

replace – v. to be used instead of (something)