GENETICS AND EVOLUTION
MOLECULAR BASIS OF INHERITANCE
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
point mutation
|
|
|
frame-shift muttion
|
|
|
silent mutation
|
|
|
both (a) and (b).
|
Detailed explanation-1: -As mentioned, sickle-cell anemia is the result of a change in a single nucleotide, and it represents just one class of mutations called point mutations.
Detailed explanation-2: -Sickle cell disease (SCD) is a monogenetic disorder due to a single base-pair point mutation in the -globin gene resulting in the substitution of the amino acid valine for glutamic acid in the -globin chain.
Detailed explanation-3: -Sickle cell is caused by a base-substitution when the adenine base in GAG is replaced by a thymine base, changing the triplet to GTG. The normal triplet when transcribed and translated codes for the amino acid glutamic acid. When the base substitution occurs, the amino acid that is translated is now valine.