Genetic Disorders

In human beings 45 chromosomes/single X/XO abnormality causes ______.

(a) Why are thalassemia and haemophilia categorized as Mendelian disorders? Write the symptoms of these diseases. Explain their pattern of inheritance in humans.

(b) Write the genotypes of the normal parents producing a haemophilic son.

A child suffering from Thalassemia is born to a normal couple. But the mother is being blamed by the family for delivering a sick baby. 

(a) What is Thalassemia?

(b) How would you counsel the family not to blame the mother for delivering a child suffering from this disease? Explain.

(c) List the values your counselling can propagate in the families.

Why is pedigree analysis done in the study of human genetics? State the conclusions that can be drawn from it.

Given below is the representation of amino acid composition not the relevant translated portion of β-chain of haemoglobin, related to the shape of human red blood cells

(a) Is this representation indicating a normal human or a sufferer from certain related genetic disease? Give reason in support of your answer.

(b) What difference would be noticed in the phenotype of the normal and the sufferer related to this gene?

(c) Who are likely to suffer more from the defect related to the gene represented the males, the females or both males and females equally? And why?

Give an example of an autosomal recessive trait in humans. Explain its pattern of inheritance with the help of a cross.

A colour-blind child is born to a normal couple. Work out a cross to show how it is possible. Mention the sex of this child.

Give an example of a human disorder that is caused due to a single gene mutation.