Why are people with O blood group called as universal donors?

'AB' Blood group individuals are called universal recipients. Justify

What is null allele?

How can erythroblasts foetalis be prevented?

Draw a schematic representation to show ZW - ZZ type of sex determination.

What is SRY?

What is sex Index?

Females are carriers of Haemophilia. Give Reason.

What is the role of the gene responsible for colour blindness in a normal human beings?

What are Y linked or holandric genes?

What is karyotyping?

What is Pedigree analysis?

What are Mendelian disorders?

Draw the symbols for
(a) Mating (b) Dizygotic twins.

What is the chemical reaction that is affected in people suffering from Albinism?