14.1 (a) Structure of chromosomes :
Each chromosome consists of two strands which are called as
chromatids. The two chromatids of a chromosome are joined together
at a point called as centromere.
(a) Structure of chromosome (b) Metaphase chromosome.
- Depending on the position of centromere a chromosome
can be of different types and attain different shapes during
anaphase. They are :
(i) Metacentric : They are V - shaped. These have centromere in the
middle of chromosome so that the two
arms are almost equal.
(ii)Sub metacentric : They are L shaped. In this centromere
is slightly away from the mid point, so that the two arms are
unequal.
(iii) Acrocentric : They are J-shaped with centromere at subterminal
position.
(iv)Telocentric : They are rod shaped, having terminal centromere.
