Short Answer Type
Long Answer Type(a) What is polygenic inheritance ? Explain with the help of a suitable example.
(b) How are pleiotropy and Mendelian pattern of inheritance different from polygenic pattern of inheritance ?
Short Answer TypeGive an example of an autosomal recessive trait in humans. Explain its pattern of inheritance with the help of a cross.
Sickle Cell Anaemia is an autosomal recessive trait in humans. The genes responsible for this disease are located in autosomes. The disease being recessive the trait should be present in homozygous condition, for it to express.
People who carry a single copy of the gene are clinically normal but are carriers of the disease and can pass on the defective gene to their subsequent generation.
Long Answer TypeA. Why is haemophilia generally observed in human males? Explain the conditions under which a human female can be haemophilic.
B. A pregnant human female was advised to undergo M.T.P. It was diagnosed by her doctor that the foetus she is carrying has developed from a zygote formed by an XX egg fertilized by Y-carrying sperm. Why was she advised to undergo M.T.P.?
Short Answer TypeDuring a medical investigation, an infant was found to possess an extra chromosome 21. Decribe the symptoms the child is likely to develop later in the life.
Long Answer TypeState and explain the ‘law of independent assortment’ in a typical Mendelian dihybrid cross.
Short Answer TypeGive a scientific term:
Exhibition of superiorityof the hybrid over both of its parents
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