1.)In a particular family, the presence of albinism is dominant. Ken and Jan was both albino having four albino children. Their albino daughter Leah met and married Liam who was also albino. Leah and Liam had four children and to the surprise of their parents one of the four grandchildren was not an albino. When considering genotypes and phenotypes explain this phenomena. Support with Punnett squares.
Posted in Biology, asked by csmith, 6 years ago. 2345 hits.
Hey fellow, this is a complicated one. Had it been in my biology textbook i would have also got a headache. I do not know about your course or your grade to explain properly but lets give it a try. You need to visit the wikipedia link i have given to see the reference to the proof of my answer.
The husband Liam has a different form of the disease which is inherited from one parent only. He has an allele for albinism which is dominant, his allele is NOT recessive. He has one normal allele which does not cause albinism and one dominant allele which causes albinism. He is heterozygous. He got his disease from one parent.
As a proof of this statement I'll like to quote from wikipedia
As for the daughter Leah, she has the normal form of the disease which is running in the family and she is homozygous recessive.
So if you draw the punnet square you can clearly get the idea that one child will have one allele for albinism from Leah and one normal allele from Liam which will be expressed as dominant in this condition because Leah's allele for albinism is recessive. So the child will not have albinism.
Dont know if this convinces you are not but as for the latest information from the wikipedia, this seems to be the possible explanation. Reply to my answer if you want further ask something.
The alternative form of gene is called allele. if an individual having same allele called homozygous and having different allel called heterozygous.
In this case ken and jha was albino.Suppose allele ‘A’ stands for albino which is dominant and ‘a’ for recessive.Thay have four albino daughter now Leah married with Liam both are albino and out of their four children one is normal.
If albino gene is dominant then this normal child does not have albino gene A.He/she got the allele from one of the albino parent so it is clear one of the parent carries normal allele.Now Leah is albino and carries recessive allele of albino i.e.homozygous.
If we put this data in punnet square we will get the genotypic ratio from which it will be clear that the normal child got the recessive allel from mother Leah and another allele from father Liam which is dominant over the recessive allele.so Liam is heterozygous carries albino gene and a normal gene.
- jayeeta sarkar 6 years ago
genes are factor(mendel) and mono mean single hybridcross mean crossing between dominant or homozygous (same zygote)and recessive or heterozygote (different zygote) we get an hybrid generation and crossing between hybrid triat with other traits there are so many xample present in text