Primer
Short preexisting polynucleotide chain to which new deoxyribonucleotides can be added by DNA polymerase. 2. A short length of RNA or single-stranded DNA that is necessary for the initiation of DNA synthesis.

Privacy
In genetics, the light of people to restrict access to their genetic information.

Probe
Single-stranded DNA or RNA molecules of specific base sequence, labeled either radioactively or immunologically, that are used to detect the complementary base sequence by  hybridization.

Product Law
A law that states that the probability of two independent events occurring simultaneously is equal to the product of the probabilities of each event occurring alone.

Product rule
The rule that states that the probability of the occurrence of independent events is the product of their separate probabilities.

Progeny
The offspring of a mating.

Prokaryote
Cell or organism lacking a membrane-bound, structurally discrete nucleus and other subcellular compartments. Bacteria are examples of prokaryotes. 2. Organisms that lack true nuclei, such as bacteria and cyanobacteria. 3. A cell without a distinct nucleus. Bacteria and some other simple organisms are prokaryotic. Compare with eukaryote. In classificatory terms, the group of all prokaryotes is paraphyletic. 4. Microorganisms that lack a membrane-bound nucleus containing chromosomes; other organelles are also absent.

Prophase
The first stage of cell division (meiotic or mitotic). During this stage, chromosomes begin to condense, the nuclear envelope breaks down, and centrioles replicate. In meiosis, the first prophase is divided into five substages: leptonema, zygonema, pachynema, and diakinesis.