Question

If a normal pigmented woman marries an albino man, 50% of their offsprings are albino and 50% of them are normal, then the women are
(a) heterozygous normal
(b) homozygous normal
(c) normal
(d) none of the above

Answer 1

Hint: Two copies of abnormal genes are required to show the disease in autosomal recessive disorders. If a woman or man is heterozygous, they are considered normal individuals but they are carriers of the disease.

Complete answer:
Albino is an autosomal recessive genetic disorder characterized by the lack of pigmentation in the eyes, skin, and hair. Mammals, fishes, birds, reptiles, and amphibians are affected by this disorder. Since it is an autosomal recessive disorder, heterozygous woman genes are crossed with the normal man i.e homozygous, it results in the formation of 50% albino offsprings and 50% are normal offsprings

Additional information:
- In general, a normal human contains 23 pairs of chromosomes. In those 23 pairs, 22 pairs are exactly the same in both males and females. They are called autosomes and in that remaining one pair, a pair of X chromosomes are present in females and a pair of X and Y chromosomes determine the male characteristics.
- If the genetic diseases caused by the differences in the autosomes are called autosomal disorders which are of two types, autosomal dominant and autosomal recessive.
- Albino is an example of an autosomal recessive disorder where two copies i.e, homozygous recessive mutated genes are required to show the disease. If a woman or man is heterozygous, they are considered normal individuals but they are carriers of the disease.

So, the correct answer is ‘heterozygous normal’

Note: In autosomal dominant disorders, one copy of the mutated gene is enough to show the disease whereas in autosomal recessive disorders two copies of abnormal genes are required to show the disease. Cystic fibrosis, sickle cell anemia, etc are examples of autosomal recessive disorders.