| A | B |
|---|
| anatomy | the study of the physical structure of humans and animals |
| antibiotic | a compound that kills or limits the growth and reproduction of bacteria |
| anaerobic | reactions that do NOT involve oxygen |
| aerobic | reactions that DO use oxygen |
| alleles | the different varieties of a gene, X or Y , T or t |
| active transport | movenment of molecules across the cell membrane using energy |
| active site | the part of an enzyme where the substrate or reacted particle bonds |
| accuracy | the amount of conformity of a measurement to its actual value |
| abiotic | nonliving parts of an environment (= light, water, soil & climate) |
| activation energy | what is needed to start a reaction, as in striking matches |
| adenine | one of 4 nitrogen bases found in RNA & DNA |
| amino acids | the building blocks of proteins, such as cysteine, serine, lysine |
| ancestry | the history of an organism’s development; ex) pedigree, lineage |
| anticodon | 3 adjacent nucleotides in tRNA that bind to a codon on mRNA |
| analogous structures | parts that serve the same purpose in different species but that evolved independently, not from the same parts in a common ancestor. Ex: bird wings, human arms, dolphin flippers |
