Question
Question: When a woman heterozygous for A blood group and heterozygous non-albino marries a man who is heteroz...
When a woman heterozygous for A blood group and heterozygous non-albino marries a man who is heterozygous non-albino and heterozygous for B blood group. The probable numbers of kinds of phenotypes in their progeny are
A. 4
B. 9
C. 8
D. 6
Solution
The ABO system in humans is controlled by a gene that has three alleles, IA , IB and i. In addition to this hyperpigmentation is recessive in nature, the condition for hypopigmentation is drawn as AA or Aa and non-albino is aa.
Complete step by step answer:
Let us represent the woman's blood group by IAi and the non-albino condition as Aa. Similarly, the man's blood group is IBi and for non-albino condition, it is AA.
The gametes and cross are given below:
Female \Male | IB | Ai | aIB | ai |
---|---|---|---|---|
AIA | AAIAIB | AAIA | AaIAIB | AaIAi |
Ai | \begin{array}{*{35}{l}} AA{{I}^{B}}i \\\\\end{array} | AAii | AaIBi | Aaii |
aIA | AaIAIB | AaIAi | aaIBi | aaIAi |
ai | AaIBi | Aaii | aaIBi | \begin{array}{*{35}{l}} aaii \\\\\end{array} |
It is important to note that AA and Aa indicate non-albino while aa indicates the albino condition.
IAIB indicates blood group AB.
IA indicates blood group A
IB indicates blood group B.
From the above table, we can easily make out that there are right phenotypes in total.
From the above table, we can see that there are 12 genotypes.
The probable ranges of varieties of phenotypes in their relatives are nine.
The phenotypes are eight.
Hence, the correct answer is 9 which is option C.
Note: The unwellness in hypopigmentation also called albinism is caused by the deficiency of tyrosinase. Albinism normally a congenital defect {congenital disorder; congenital abnormality} is a genetic disorder, that's characterized by very little or no production of the pigment melanin, or due to lack of amino alkanoic acid. This enzyme helps the body to alter the organic compound amino alkanoic acid into melanin pigment. In people suffering from hypopigmentation, this enzyme is inactive and no melanin pigment is made, resulting in white hair and really light-weight skin color.