for normal eye, located on X-chromosome duplicates,
the eyes become smaller, resulting in a disorder called
Bar eye.• In general, duplications are less deleterious to the
individual than deficiencies.
- translocation
• Translocation is the separation of a chromosome
segment, and its union to a non-homologous
chromosome.
• It is of two types – simple and reciprocal.
• In simple translocation, one chromosome shows
deletion or deficiency, while a non homologous
chromosome comes to have an additional segment.
• It is called reciprocal, when segments are exchanged
between two non homologous chromosomes.
• Translocations may be homozygotic, if involving
segments of two chromosomes of a pair, or
heterozygotic, if only one chromosome of a pair is
translocated.
• When both chromosomes are broken near the
kinetochore, a new chromosome may be formed by
centric fusion or Robertsonian translocation.
• The fusion creates a metacentric chromosome,
with two arms in the form of a V, and a small fragment,
which tends to be eliminated.
• It is a process that establishes a new type of
chromosome and reduces the somatic chromosome
number of the species.