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 your answer with Punnett squares.

Question

anonymous · Answer

hey again! lol so i c the dominant gene is albino so i use a capital A and the normal ones who are healthy would be a lower case a right?

shrutipande9 · Answer

are you sure it says dominant? because albinism is due to recesive trait...

anonymous · Answer

just how i wrote it thats what it have. it says albinism is dominant but i am unsure how to attemt

shrutipande9 · Answer

ok lets go by dominant...so if a person has albinism then he must have atleast 1 A...CORRECT?

anonymous · Answer

yes:)

shrutipande9 · Answer

cool...now they say that leah and liam have 1 child out of 4 which is not an albino..so his genotype is aa..?

anonymous · Answer

ummm how did u get that?

shrutipande9 · Answer

see albinism is due to dominant allele..correct? so AA and Aa both will have albinism...so what is left is aa which does not have A so no albinism

anonymous · Answer

so how would i set it up in punnet square .sorry im a visual person

anonymous · Answer

u did AA and aa on tope of the punnet square hey?

shrutipande9 · Answer

ok lets go visual then....now tell me what are the possible genotypes of an aalbino person?

anonymous · Answer

um let me work it out to see 1 sec :)

shrutipande9 · Answer

ok sure...

shrutipande9 · Answer

for a person to be albino he has to have atleast 1 A in his genotype

anonymous · Answer

i have to focus on leah and her husbands genotype right?cus we ar finnding the grand children?

shrutipande9 · Answer

yes...but for that we need 2 work out the grandparents cross as well to know the genotype of leah

shrutipande9 · Answer

see for eg i give u the genotype AA...can u tell me the phenotype?

anonymous · Answer

oh so do the granparents first in the punnet square

shrutipande9 · Answer

yep...but its ok if we dont go into the grandparents details...can u ans my ques?

anonymous · Answer

um would i have to do the punnet to answer that?

shrutipande9 · Answer

nope...no punnet...see A gives albinism and a is normal person
so what would be the phenotype of AA?

anonymous · Answer

Aa?

shrutipande9 · Answer

I  am asking about phenotype...
see genotype is AA phenotype is albinism...

anonymous · Answer

oh sorry

shrutipande9 · Answer

so u know exactly what is genotype and a phenotype right? or should we just revise it once?

anonymous · Answer

75% would be  albino and 25% is normal

shrutipande9 · Answer

ok ok..wait...tell me how did u get that? show me the punnet?

anonymous · Answer

um because of how they asked the questithe question. they said  3 are albino and 1 is normal

anonymous · Answer

3 persons =75% and 1 is 25%

shrutipande9 · Answer

ohh ok...actually i want u to think the other way round...that would be easier for u to understand....with me?

shrutipande9 · Answer

Aa=albino
AA=albino
aa=normal 
is this good?

anonymous · Answer

yes

shrutipande9 · Answer

cool...now the only child which is normal must have the genotype aa...correct?

anonymous · Answer

yes

shrutipande9 · Answer

great...now when u right the genotype of a child...u take 1 letter from mother and one from father correct?

anonymous · Answer

yea so its AA

shrutipande9 · Answer

|dw:1385054315199:dw|

shrutipande9 · Answer

See now leah and liam both are albino...so their genotype has to be either AA or Aa..correct?
now 1 of their child is aa so for their child to have aa both of them should have atleast 1 small a...correct?

anonymous · Answer

yes

shrutipande9 · Answer

|dw:1385054490212:dw|

anonymous · Answer

ohhhh i c

shrutipande9 · Answer

so both of them should have atleast 1 a like this|dw:1385054596720:dw|