Which mutation causes change in allele?
Chemical
Radiation
Transposons
Spontaneous mutation
$A$ : Pseudoalleles are actually closely linked genes.
$R$ : These can be identified easily as both affect different characters, providing separate phenotypes
Frequency of Down’s syndrome increases when the maternal age is
The chromosome shown in the diagram below is broken at the points which are indicated by the arrows and the genes between these points became inverted
The resulting order of the genes will be
Mongolism syndrome is caused by
A medical technician while observing a human blood smear under the microscope notes the presence of barrbody close to the nuclear membrane in the $WBC$. This indicates that person under investigation is