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प्रश्न
Based on your understanding of genetic code, explain the formation of any abnormal hemoglobin molecule. What are the known consequences of such a change?
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उत्तर
The defect is caused by the substitution (trans version) of Glutamic acid (Glu) by Valine (Val) at the sixth position of the betaglobin chain of the haemoglobin molecule. The substitution of amino acid in the glob in protein results due to the single base substitution at the sixth codon of the betaglobin gene from GAG to GUG. The mutant haemoglobin molecule undergoes polymerisation under low oxygen tension causing the change in the shape of the RBC from biconcave disc to elongated sickle-like structure. Sickle-shaped red blood cells that obstruct capillaries and restrict blood flow to an organ resulting in ischaemia, pain, necrosis, and often organ damage.
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संबंधित प्रश्न
Differentiate between the genetic codes given below:
Unambiguous and Universal
Name the anticodon required to recognize the following codon: GCA.
Genetic code is ______.
Frame shift mutation occurs when ______.
The number of base substitution possible in amino acid codons is ______.
Out of A=T, G =C pairing, bases of DNA may exist in alternate valency state owing to arrangement called ______.
The change of the light coloured variety of peppered moth (Biston betularia) to its darker variety (Biston carbonarid) is due to ______.
H. J. Muller was awarded Nobel Prize for his ______.
Amino acids which are specified by single codons are ______.
Sickle cell anemia results from a single base substitution in a gene, thus it is an example of ______.
If the sequence of bases in coding strand of DNA is ATTCGATG, then the sequence of bases in mRNA will be ______.
AUG on the mRNA will result in the activation of which of the following RNA having the correct combination of amino acids:
| Site A | Site B | |
| A. | UAC | Methionine |
| B. | Methionine | UAC |
| C. | Methionine | AUG |
| D. | AUG | Methionine |
Which of the following organ is essential for photorespiration?
Statement I: The codon ‘AUG’ codes for methionine and phenylalanine.
Statement II: ‘AAA’ and ‘AAG’ both codons code for the amino acid lysine.
In the light of the above statements, choose the correct answer from the options given below.
A single base mutation in a gene may not ‘always’ result in loss or gain of function. Do you think the statement is correct? Defend your answer.
Who proposed that the genetic code for amino acids should be made up of three nucleotides?
All the 64 codons in the dictionary of genetic code were deciphered by ______.
