The "cri-du-chat" syndrome is caused by change in chromosome structure involving
Deletion
Duplication
Inversion
Translocation
The reason why some mutations which are harmful do not get eliminated from the gene pool, is that
If the genotype of an individual consists of only one type of genes at same locus. It is called
One of the parents of a cross has a mutation in its mitochondria. In that cross, that parent is taken as a male. During segregation of ${F_2}$ progenies that mutation is found in
The defect sickle-cell anaemia is caused by the ______ of glutamic acid by valine at the $6^{th}$ position of the ______ globin chain of the haemoglobin molecule.
Alleles which show independent effect are called