the structures on which the genes are carried which,in turn, are the mechanism by which hereditary characteristics are transmitted from parents to off-spring.
(the genes; are carried; ) (the structures on which the genes are carried which; are; the mechanism by which hereditary characteristics are transmitted from parents to off-spring) (hereditary characteristics; are transmitted; from parents)
the genes the structures on which the genes are carried which hereditary characteristics
are carried are are transmitted
the mechanism by which hereditary characteristics are transmitted from parents to off-spring
from parents