Which disease results from the genetic inability to synthesize a single enzyme ?

A. Diabetes

B. Phenylketonuria

C. Colour-blindness

D. Down's syndrome

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  1. A child is bom with an extra chromosome in each of its cells. This is usually the result of
  2. Exhibition of superiority by a hybrid over both of its parents is called
  3. The chromosomal theroy of heredity implies that
  4. The nuclear membrane completely disappears during
  5. How many meiosis will be required to produce 102 pollen-grains ?
  6. The science dealing with study of inheritance and variation is
  7. The condition in which only one allele of a pair is present is known as
  8. The scientists who rediscovered the Mendel's laws are
  9. Base substitutions from base analogues I are called
  10.  A person meets with an accident and great loss of blood has occurred. There is no time to analyse…
  11. Linked genes may be separated by the process of
  12. The best method to determine whether an individual is homozygous or heterozygous is
  13. Among the following which is a test cross?
  14. A codon is a sequence of 3 nucleolides on
  15. In the Operon concept, the regulator gene regulates chemical reactions in the cell by
  16. Which one of the following chemical characteristics is not common to all living beings ?
  17. If an individual does not breed true for its characters, it is called
  18. Mutations which are not dominant are not lost by a gene pooL This is known as
  19. The crossing of a homozygous tall plant with a dwarf would yield plants in the ratio of
  20.  A chemical mutagen is
  21. The genetic constitution of an organism is known as
  22. DNA duplication occurs in
  23. Some people experience PTC paper on tongue as bitter, others as tasteless. This character is hereditary…
  24. A colour-blind man marries the daughter of a colour-blind person. In their progeny
  25. Chromosomes exhibit minimum coiling during
  26. Down's syndrome is an example of
  27. A functional unit of a gene which specifies synthesis of one poly-peptide is known as
  28. In humans, an example of sex-linked trait is
  29. An offspring of two homozygous parents different from one another by alleles at only one gene locus…
  30. In a monohybrid cross the Fi ratio of a backcross is