NCI Dictionary of Genetics Terms

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Welcome to the NCI Dictionary of Genetics Terms, which contains technical definitions for more than 150 terms related to genetics. These definitions were developed by the PDQ® Cancer Genetics Editorial Board to support the evidence-based, peer-reviewed PDQ cancer genetics information summaries.

2 results found for: B
band
(band)
When chromosomes at a particular stage in cell division are stained using one of several laboratory techniques, a specific pattern of light and dark stripes (bands) appears when the chromosomes are viewed through a microscope; the banding pattern assists in assigning each chromosome its particular number and evaluating its structure.
base pair
(bays payr)
Two nitrogen-containing bases pair together between double-stranded DNA; only specific combinations of these bases (e.g., adenine with thymine; guanine with cytosine) are possible, a fact which facilitates accurate DNA replication; when quantified (e.g., 8 base pairs, or bp), this term refers to the actual number of base pairs in a sequence of nucleotides.