Cruciform is a term for physical manifestations resembling a common cross or Christian cross. The label can be extended to architectural shapes, biology, art, and design. Cruciform architectural plan Christian churches are commonly described as having a cruciform architecture. In Early Christian, Byzantine and other Eastern Orthodox forms of church architecture this is likely to mean a tetraconch plan, a Greek cross, with arms of equal length or, later, a cross-in-square plan. In the Western churches, a cruciform architecture usually, though not exclusively, means a church built with the layout developed in Gothic architecture. This layout comprises the following: An east end, containing an altar and often with an elaborate, decorated window, through which light will shine in the early part of the day. A west end, which sometimes contains a baptismal font, being a large decorated bowl, in which water can be firstly, blessed (dedicated to the use and purposes of God) and then used for baptism. North and south transepts, being "arms" of the cross and often containing rooms for gathering, small side chapels, or in many cases other necessities such as an organ and toilets. The crossing, which in later designs often was under a tower or dome. In churches that are not oriented with the altar at the geographical east end, it is usual to refer to the altar end as "liturgical east" and so forth. Methodist tabernacles also have a cruciform shape. Another example of ancient cruciform architecture can be found in Herod's temple, the second Jewish temple. Cruciform DNA DNA can undergo transitions to form a cruciform shape, including a structure called a Holliday junction. This structure is important for the critical biological processes of DNA recombination and repair mutations that occur in the cell. Cruciform joint A cruciform joint is a specific joint in which four spaces are created by the welding of three plates of metal at right angles. Cruciform manuscript A cruciform manuscript was a form of Anglo-Saxon / Insular manuscript written with the words in a block shaped like a cross. Cruciform melody In music, a melody of four pitches where a straight line drawn between the outer pair bisects a straight line drawn between the inner pair, thus forming a cross. In its simplest form, the cruciform melody is a changing tone, where the melody ascends or descends by step, skips below or above the first pitch, then returns