| A | B |
|---|
| photosynthesis | the process by which plants use the energy from sunlight to produce sugar |
| phenotype | a physical characteristic |
| pesticides | chemicals used to kill organisms viewed as pests |
| pedigree | family trees showing the occurrence of traits in parents and offspring across multiple generations |
| parasitism | one organism benefits at the expense of the other (the host) |
| paleontology | a study of the history and development of life on Earth as based on the fossil record |
| organelles | very tiny structures that exist within a cell that allow the cell to function |
| nucleotide | the combination of a sugar, a phosphate molecule, and a nitrogenous base |
| nucleus | a large structure inside a cell that contains the genetic material (DNA and RNA) and controls the cells activities |
| osmosis | the movement of water molecules across a selectively permeable membrane |
| Pangaea | the hypothetical supercontinent that existed when all Earth’s landmasses were joined before the Triassic period |
| passive transport | the movement of molecules across the cell membrane without the expenditure of energy |
| peptide bonds | the bond that holds two amino acids together |
| P generation | the original, or parent generation used in genetic crosses |
| phosphorus cycle | the absorption of phosphorus from the soil by plant roots and then by herbivores and the movement of phosphorus back to the soil from the decay of dead plants and animals |
