Quote:
dear all can anyone answere me the question no 8
(8) What is the chance of diabetic baby born to parents both heterozygous normal ?
a. Zero
b. ¼
c. ½
d. ¾
e. None of these
anyone tells me why 1/4 what about option e, because question doesnt tell the history of parents parent
|
Dear jtalpur, its reason is the fact that parents are ''heterozygous'' meaning each of them[parents] have one allele for the disease. so when u do the cross bw such parents the ratio comes out is 25 % or 1/4. u can understand this concept if u know how to make a cross bw traits.
Suppose a person has 't' allele for diabetes, 'T' [capital] for normal. one parent has 'Tt' and the other likewise has 'Tt' , now then cros [Tt into Tt] and make its possible subsets like this : TT, Tt, tT, tt. in this configuration u can see the letters ''tt'' stands for the disease and its ratio is 25% , therefore it is 1/4 .
hope this concept is clear enough for you.