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. The number of characters investigated by Mendel was
  2. Albinism in com plants is best described as
  3. The scientists who rediscovered the Mendel's laws are
  4. How many meiosis will be required to produce 102 pollen-grains ?
  5. In a monohybrid cross the Fi ratio of a backcross is
  6. A codon is a sequence of 3 nucleolides on
  7. Which disease results from the genetic inability to synthesize a single enzyme ?
  8. Mutations which are not dominant are not lost by a gene pooL This is known as
  9. Some people experience PTC paper on tongue as bitter, others as tasteless. This character is hereditary…
  10. The chromosomal theroy of heredity implies that
  11. Linked genes may be separated by the process of
  12. The science dealing with study of inheritance and variation is
  13. Linkage is
  14. Diakinesis is characterised by
  15. DNA duplication occurs in
  16. Crossing over in meiosis occurs in
  17. Which one of the following chemical characteristics is not common to all living beings ?
  18. The first person to induce mutations was
  19. Klinefelter's syndrome is developed when the chromosome in male is
  20. The nuclear membrane completely disappears during
  21. Dyad is
  22. Transfer of a gene or genes through a virus is called
  23.  A person meets with an accident and great loss of blood has occurred. There is no time to analyse…
  24. The segment of DNA which participates in crossing over is known as
  25. A functional unit of a gene which specifies synthesis of one poly-peptide is known as
  26. When is the sex of an offspring decided
  27. In humans, an example of sex-linked trait is
  28. Chromosomes exhibit minimum coiling during
  29. A giant chromosome having many chromo-nemata lying side by side all along their length is called
  30. Down's syndrome is an example of