Question

Please answer in (~250-300 words)

Thanks in advance!!!

The famous silent screen actor, Charlie Chaplin, was sued for paternity in the 1920’s. His defense lawyers used his and the baby’s blood types to show Charlie could not have been the father. Explain how this could have been done considering the only tests that were available at that time where blood type, A, B, O and the Rhesus factor, + or -.

Answer 1

Charlie Chaplin was involved in a legal battle over the paternity of a child born to Joan Barry. The baby was of blood type B, the mother was of blood type A, and Chaplin's blood type O.

For a gene determining blood group there are three versions (called “alleles”): A, B, and O. A person's blood type is determined by which allele he/she inherits from each parent. A and B genes are “co-dominant”. In other words, if both an A and B allele are inherited, both are expressed. O is a recessive allele.

Allele Inherited From One Parent	Allele Inherited From the Other Parent	Child’s Genotype	Child’s Blood Type (Phenotype)
A	A	AA	A
B	B	BB	B
B	A	AB	AB
A	B	AB	AB
A	O	AO	A
B	O	BO	B
O	O	OO	O

If a person's blood type is A, he or she has either two A alleles or one A allele and one O allele. Similarly, if a person has type B blood, this indicates the presence of either two B alleles or one B allele and one O allele

For an A group mother the alleles can be either two A alleles or one A allele and one o allele. She can pass either A allele or an O allele to her offspring.

For an O group father the two alleles will be O only. He can pass only O allele to his offspring.

So the possibility of Child genotype will be Either AO or OO. That means the blood group can be either O or A.

By using this fact chaplin’s advocate proved that he could not be the father of a child having b blood group.

Although blood tests definitively excluded Chaplin as the father, the court did not allow this evidence to be admitted, and Chaplin was ordered to pay child support to Barry.