Chromosomal integration site
A chromosomal location where foreign DNA can be integrated, often without impairing any essential function in the host organism.

Chromosomal polymorphism
The occurrence of one to several chromosomes in two or more alternative structural forms within a population; the structurally changed chromosomes are the result of chromosome mutations (i.e., any structural change involving the gain, loss or re-location of chromosome segments). Chromosome (Gr. chroma, colour + soma, body)1. A single DNA molecule, a tightly coiled strand of DNA, condensed into a compact structure in vivo by complexing with accessory histones or histone –like proteins

Chromosome aberration
Abnormal structure or number of chromosomes; includes deficiency, duplication, inversion, translocation, aneuploidy, polyploidy, or any other change from the normal pattern. Chromosome banding staining of chromosomes in such a way that light and dark areas occur along the length of the chromosomes in repeatable patterns. Lateral comparisons identify pairs. Each chromosome can be identified by its banding pattern

Chromosome mutation
A change in the gross  structure of a chromosome, usually causing severely deleterious effects in the organism. They are often due to an error in pairing during the crossing –over stage of meiosis. The main types of chromosome mutation are translocation, duplication, deletion and inversion

Chromosome theory of inheritance
The theory that chromosomes carry the genetic information and that their behaviour during meiosis provides the physical basis for segregation and independent assortment.

Chromosome walking
1 . A technique that identifies overlapping cloned DNA fragments that form one continuous segment of a chromosome. These fragments can be generated wither by random shearing or by partial digestion with a four-base-pair cutter such as Sau3A. A series of colony hybridizations is then carried out, starting with some cloned fragment which has already been identified and which is known to be in the region encompassed by the overlapping clones. This identified fragment is used as a probe to pick out clones containing adjacent sequences. These are then used as probes themselves to identify clones carrying sequences adjacent to them and so on. At each round of hybridization one “walks” further along the chromosome from the initial fragment. See positional cloning.
2. A technique for cloning everything in the genome around a known piece of DNA (the starting probe). You screen a genomic library for all clones hybridizing with the probe, and then figure out which one extends furthest into the surrounding DNA. The most distal piece of this most distal clone is then used as a probe, so that ever more distal regions can be cloned. This has been used to move as much as 200 kb away from a given starting point (an immense undertaking). Typically used to “walk” from a starting point towards some nearby gene in order to clone that gene. Also used to obtain the remainder of a gene when you have isolated a part of it