Answer the following questions: Huntington\'s and Cystic Fibrosis 1. What is the

Question

Answer the following questions:

Huntington's and Cystic Fibrosis

1. What is the percentage likelihood that the couple will have a child who has both Huntington’s disease and cystic fibrosis?

2. What is the percentage likelihood that the couple will have a child who has neither Huntington’s disease nor cystic fibrosis?

3. What is the percentage likelihood that the couple will have a child who is a carrier for cystic fibrosis?

Karyotyping

4. How are an individual’s chromosomes karyotyped?

5. How does nondisjunction occur? What happens to the gametes that are a product of nondisjunction?

Explanation / Answer

Ans-1

HD is inherited as an autosomal dominant disorder, meaning that each child of an affected parent has a 50:50 chance of inheriting the genetic mutation that causes HD, and men and women are equally likely to inherit the mutation.

Ans-2

What is the percentage likelihood that the couple will have a child who has neither Huntington’s disease nor cystic fibrosis?

Ans-3

CF is inherited in an autosomal recessive manne. It is caused by the presence of mutations in both copies of the gene for the cystic fibrosis transmembrane conductance regulator (CFTR) protein.

If the couple is carries ( i.e. one copy of the gene is mutated ) for cystic fibrosis than the child will have

Ans-4

Karyotype is the number and appearance of chromosome i.e. what these chromosomes look like under a light microscope .

Chromosome karyotyping involves following steps-

Ans-5

Non-disjunction is the failure of homologous chromosome or sister chromatids to separate during cell division.

It happens when two homologous chromosomes or sister chromatids fail to separate (disjoin) and thus both migrate to the same pole. This gives rise to two types of gamete. One type possesses two copies of the chromosome, whereas the other type lacks that chromosome altogether.

This will leads to –

Monosony- Loss of one chromosome in daughter cell (2n-1)

Trisony –daughter cell will have 2n+1 chromosome etc

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.