Isochore

noun

1. A <xref>line</xref> drawn on a <xref>pressure</xref> / <xref>volume</xref> / <xref>temperature</xref> <xref>graph</xref> through all <xref>points</xref> having the same <xref>value</xref> of the volume
2. A <xref>contour</xref> showing points of equal <xref>vertical</xref> <xref>thickness</xref> of <xref>strata</xref>; equal to an <xref>isopach</xref> if strata are horizontal
3. A <xref>sequence</xref> of <xref>DNA</xref> that has a reasonably <xref>constant</xref> <xref>proportion</xref> of pairs of <xref>guanine</xref> and <xref>cytosine</xref> bases, and is rich in <xref>genes</xref>