Which of the following amino acid substitution in the beta chain of the haemoglobin molecule leads to the development of sickle cell anaemia?
1. Arginine by tyrosine
2. Tyrosine by phenylalanine
3. Valine by Glutamic acid
4. Glutamic acid by Valine
1. | The former is a quantitative problem of synthesising too few globin molecules while the latter is a qualitative problem of synthesising an incorrectly functioning globin. |
2. | The former is a qualitative problem of synthesising too few globin molecules while the latter is a quantitative problem of synthesising an incorrectly functioning globin. |
3. | Both disorders are qualitative problems of synthesising too few globin molecules. |
4. | Both disorders are quantitative problems of synthesising too few globin molecules. |
Sickle cell anaemia has not been eliminated from the African population because:
1. It is controlled by recessive genes
2. It is not a fatal disease
3. It provides immunity against malaria
4. It is controlled by dominant genes