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

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

`50%`

B

`25%`

C

`100%`

D

`75%`

Text Solution

Verified by Experts

The correct Answer is:
A
In the given question 50% of offsprings would be affected by this disorder because Down's syndrome is the result of trisomy, in which chromosome pair number 21st contains an extra copy of chromosome (2A + 1). Affected mother will produce 50% normal egg cells and rest 50% eggs are of abnormal type.
Promotional Banner

Topper's Solved these Questions

  • PLANT KINGDOM

    NEET PREVIOUS YEAR (YEARWISE + CHAPTERWISE)|Exercise MCQ|107 Videos

  • RE-NEET 2020

    NEET PREVIOUS YEAR (YEARWISE + CHAPTERWISE)|Exercise All Questions|90 Videos

Similar Questions

Explore conceptually related problems

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

Down's syndrome in caused by an extera copy of chromosome number 21 . What percentage of offspring is produced by an affected mother and a normal father .

Down's syndrome is due to trisomy of 21st chromosome caused by

A mother is afflicted by Down's syndorme causerd by an extra copy of chromosome 21 Father is normal .percentage of offspring affected by the disorder would be

Read the following text and answer the following questions on the basis of the same: Down syndrome (sometimes called Down's syndrome) is a condition in which a child is born with an extra copy of their 21st chromosome hence its other name, trisomy 21. The affected individual mental retarded, short statured with small round, head, furrowed tongue and partially open mouth, Physical, psychomotor and mental development is retarded. Down Syndrome is an extra copy which chromosome

Read the following text and answer the following questions on the basis of the same: Down syndrome (sometimes called Down's syndrome) is a condition in which a child is born with an extra copy of their 21st chromosome hence its other name, trisomy 21. The affected individual mental retarded, short statured with small round, head, furrowed tongue and partially open mouth, Physical, psychomotor and mental development is retarded. The number of chromosomes a child with Down syndrome has is

Read the following text and answer the following questions on the basis of the same: Down syndrome (sometimes called Down's syndrome) is a condition in which a child is born with an extra copy of their 21st chromosome hence its other name, trisomy 21. The affected individual mental retarded, short statured with small round, head, furrowed tongue and partially open mouth, Physical, psychomotor and mental development is retarded. Down syndrome is caused due to

Read the following text and answer the following questions on the basis of the same: Down syndrome (sometimes called Down's syndrome) is a condition in which a child is born with an extra copy of their 21st chromosome hence its other name, trisomy 21. The affected individual mental retarded, short statured with small round, head, furrowed tongue and partially open mouth, Physical, psychomotor and mental development is retarded. Down syndrome is

Read the following text and answer the following questions on the basis of the same: Down syndrome (sometimes called Down's syndrome) is a condition in which a child is born with an extra copy of their 21st chromosome hence its other name, trisomy 21. The affected individual mental retarded, short statured with small round, head, furrowed tongue and partially open mouth, Physical, psychomotor and mental development is retarded. One of this trait is seen in a person with Down syndrome

In Down syndrome , karyotyping has shown that the disoeder is associated with trisomy of chromosome number 21 usually due to:

NEET PREVIOUS YEAR (YEARWISE + CHAPTERWISE)-PRINCIPLES OF INHERITANCE AND VARIATION -MCQ
  1. Two crosses between the same pair of genotypes or phenotypes in which ...

    Text Solution

    |

  2. the linkage map of X -chroosomes of fruitfly has 66 units with yellow ...

    Text Solution

    |

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

    Text Solution

    |

  4. The genes controlling the seven pea characters studied by Mendel are n...

    Text Solution

    |

  5. Which one of the following traits of garden pea studied by Mendel was ...

    Text Solution

    |

  6. Which of the following discoveries resulted in a Nobel Prize

    Text Solution

    |

  7. When a cluster of genes shows linkage behaviour they

    Text Solution

    |

  8. In Drosophila, the sex is determined by

    Text Solution

    |

  9. Genes for cytoplasmic male sterility in plants are located in

    Text Solution

    |

  10. In recent years,DNA sequences (nucleotide sequence) of maternal DNA an...

    Text Solution

    |

  11. Genetic map is one that :

    Text Solution

    |

  12. There are three genes a, b, c, percentage of crossing over between a a...

    Text Solution

    |

  13. Which of the following is the example of sex-linked disease?

    Text Solution

    |

  14. Which of the following is the example of pleiotropic gene , -

    Text Solution

    |

  15. Change in the sequence of nucleotide in DNA is called as

    Text Solution

    |

  16. A plant of F(1)-generation has genotype 'AABbCC'. On selfing of this p...

    Text Solution

    |

  17. Mendel obtained wrinkled seeds in pea due to deposition of sugars inst...

    Text Solution

    |

  18. Which of these do not follow independent assortment?

    Text Solution

    |

  19. Inheritance would be extranuclear in case of

    Text Solution

    |

  20. Number of Barr bodies in XXXX female would be

    Text Solution

    |