Home
Class 12
BIOLOGY
Down's syndrome is caused by an extra c...

Down's syndrome is caused by an extra copy of chromosome number 21. what percentage of offspring produced by an affected mother and a normal father would be affected by this disorder ?

A

`25%`

B

`100%`

C

`75%`

D

`50%`

Text Solution

Verified by Experts

The correct Answer is:
D
Promotional Banner

Topper's Solved these Questions

  • MINERAL NUTRITION

    MBD PUBLICATION|Exercise Question Bank|75 Videos
  • MORPHOLOGY OF FLOWERING PLANTS

    MBD PUBLICATION|Exercise QUESTION BANK|186 Videos

Similar Questions

Explore conceptually related problems

Correct the underlined portions. Down syndrome is caused by an extra chromosome 20.

What is the diploid chromosome number in a person suffering from down syndrome ?

What will be the phenotypic ratio of offspring from a marriage between colourblind father and normal mother ?

A man, whose father was colourblind, marries a women who had a colourblind mother normal father. What percentage of male children of this couple will be colourblind ?

Due to nondisjunction of chromosomes during spermatogensis, some sperms carry both sex chromosomes (22A + XY) and some sperms do not carry any sex chromosome (22A + O). If these sperms fertilise normal eggs (22A + X), what types of genetic disorders respectively appear among the offspring ?

Due to the nondisjunctiuon of chromosomes during spermatogenesis, sperms carry both sex chromosomes (22A + XY) and some sperms do not carry any sex chromosome (22A + O). If these sperms fertilise normal eggs (22A + X), what types of genetic disorders appear among the offsprings ?

MBD PUBLICATION-MOLECULAR BASIS OF INHERITANCE-QUESTION BANK
  1. The linkage map of X- chromosomes of fruitfly has 66 units with yellow...

    Text Solution

    |

  2. In lac operon the genes a , y and z code respectively for

    Text Solution

    |

  3. Down's syndrome is caused by an extra copy of chromosome number 21. w...

    Text Solution

    |

  4. During translation initiation in prokaryotes a GTP molecule is neede...

    Text Solution

    |

  5. The place where RNA - polymerase attaches with the DNA is called :

    Text Solution

    |

  6. The total number of nitrogenous bases in human genome is estimated to ...

    Text Solution

    |

  7. Which of the following pairs is correctly matched with regard to the c...

    Text Solution

    |

  8. DNA repairing is done by :

    Text Solution

    |

  9. The function of promotor of lac- operon is to :

    Text Solution

    |

  10. Oncogenes were discovered by :

    Text Solution

    |

  11. Choose the wrong statement :

    Text Solution

    |

  12. When a mutation is limited to the substitution of one nucleotide for a...

    Text Solution

    |

  13. During transcription if nucleotide sequence of DNA strand that is be...

    Text Solution

    |

  14. During the replication of a bacterial chromosome, DNA synthesis starts...

    Text Solution

    |

  15. In genetic code dictionary codons used to code for all the 20 essent...

    Text Solution

    |

  16. Which one of the following triplet codes is correctly matched with its...

    Text Solution

    |

  17. Find the correct match :

    Text Solution

    |

  18. The codon for anticodon 3^'-UUA-5^' is :

    Text Solution

    |

  19. Splicing of RNA depends on :

    Text Solution

    |

  20. In Lac operon , i gene codes for :

    Text Solution

    |