A child is bom with an extra chromosome in each of its cells. This is usually the result of

A. nondisjunction

B. crossing over

C. segregation

D. hybridization

You can do it
  1. A giant chromosome having many chromo-nemata lying side by side all along their length is called
  2. Klinefelter's syndrome is developed when the chromosome in male is
  3. Albinism in com plants is best described as
  4. Exhibition of superiority by a hybrid over both of its parents is called
  5. In the Operon concept, the regulator gene regulates chemical reactions in the cell by
  6. The best method to determine whether an individual is homozygous or heterozygous is
  7. Among the following which is a test cross?
  8. The term 'meiosis' was coined bv
  9. The nuclear membrane completely disappears during
  10. In humans, an example of sex-linked trait is
  11. Crossing over in meiosis occurs in
  12. The crossing of a homozygous tall plant with a dwarf would yield plants in the ratio of
  13. Which one of the following chemical characteristics is not common to all living beings ?
  14. Linkage is
  15. The first person to induce mutations was
  16. A functional unit of a gene which specifies synthesis of one poly-peptide is known as
  17. The scientists who rediscovered the Mendel's laws are
  18. The number of characters investigated by Mendel was
  19. Mutations which are not dominant are not lost by a gene pooL This is known as
  20. The segment of DNA which participates in crossing over is known as
  21. Chromosomes exhibit minimum coiling during
  22. The science dealing with study of inheritance and variation is
  23. Down's syndrome is an example of
  24. The condition in which only one allele of a pair is present is known as
  25. An offspring of two homozygous parents different from one another by alleles at only one gene locus…
  26. DNA duplication occurs in
  27. Base substitutions from base analogues I are called
  28. The chromosomal theroy of heredity implies that
  29. The genetic constitution of an organism is known as
  30. Transfer of a gene or genes through a virus is called