Advertisements
Advertisements
प्रश्न
Why is thalassemia cotegorised as a Mendelian disorder? Write the symptoms and explain the causes of the disease. How does it differ from Sickle cell anaemia?
Advertisements
उत्तर
- Mendelian disorders are caused by changes or mutations in a gene. Thalassemia is caused by a gene deletion or mutation that codes for the alpha (a) or beta (P) globin chains of the haemoglobin molecule. Hence Thalassemia is a hereditary condition.
- It is a quantitative problem of synthesising a small number of globin molecules.The alpha chain is controlled by two genes on chromosome 16, HBAl and HBA2, while the β chain is controlled by a single gene on chromosome 11, HBB.
- A deletion or mutation in any of these genes reduces the production of the corresponding globin chains. Thalassemia symptoms include anaemia, pale yellow complexion, changes in the size and shape of RB Cs, sluggish growth and development, dark urine, and so on.
- Massive blood transfusion is needed for these patients.
- Thalassemia varies from sickle cell anaemia in the following ways: Thalassemia is a quantitative problem caused by the inability to synthesise a sufficient number of globin molecules, whereas sickle cell anaemia is a qualitative problem caused by the inability to synthesise an improperly functioning globin.
APPEARS IN
संबंधित प्रश्न
What is the reason for the 21st trisomy?
Identify the characteristics that are observed in an individual suffering from Klinefelter syndrome.
i. Gynaecomastia, under developed testis and no spermatogenesis.
ii. Voice pitch is harsh.
iii. They are tall with long arms.
Match Column I with Column II and select the correct option:
| Column I | Column II | ||
| p. | Pleiotropy | I. | More than two alleles occur at the same locus on homologous chromosomes |
| q. | Multiple alleles | II. | Expression of both the alleles m heterozygous condition |
| r. | Polygenic | III. | Multiple effect of single gene |
| s. | Co-dominance | IV. | Single phenotypic character influenced by more than two genes |
The person with Turner’s syndrome has ______.
Down’s syndrome is due to ______.
A person with 47 chromosomes due to an additional Y-chromosome suffers from a condition called ______.
If both parents are carriers for thalassaemia, which is an autosomal recessive disorder, what are the chances of pregnancy resulting in an affected child?
Read the following and answer from given below:
Turner's syndrome is an example of monosomy. It is formed by the union of an allosome-free egg and a normal 'X' containing sperm or a normal egg and an allosome-free sperm. The individual has 2n = 45 chromosomes (44 + X0) instead of 46. Such individuals are sterile females who have rudimentary ovaries, underdeveloped breasts, small uterus, short stature, webbed neck, and abnormal intelligence. They may not menstruate or ovulate. This disorder can be treated by giving female sex hormones to women from the age of puberty to make them develop breasts and have menstruation. This makes them feel more normal.
The number of Barr bodies present in a female with Turner's syndrome is ______
Fused ear lobes appear in the progeny due to an autosomal recessive gene. Work out the genotypes of number in the given pedigree.
Which of the following is the primary cause of Mendelian disorders?
