Complete question: Sickle-shaped red blood cells result from a mutation in the gene that codes for hemoglobin. This mutation results in sickle-cell anemia. A partial sequence of bases from a normal hemoglobin gene and a sequence that results in sickle-cell anemia are shown below (the diagram is in the attached file)
What type of mutation is depicted in this sequence?
Answer:
The type of mutation is known as SUBSTITUTION.
Step-by-step explanation:
Sickle cell anaemia is an inherited disease caused by abnormal shape of the red blood cell. This abnormal red blood cell contains less haemoglobin and cannot transport oxygen efficiently round the body. Sickle-shaped (abnormal) red blood cells result from a MUTATION in the gene that codes for hemoglobin.
Mutation is the random changes in DNA that alters genetic information and so introduce new characteristics. The different categories of mutations include:
--> Chromosomal mutation and
--> Point mutation.
SUBSTITUTION is a type of point mutation in which one base is incorrectly added during replication and replaces the pair in the corresponding position on the complementary strand. From the diagram, a partial sequence of bases from a normal hemoglobin gene and a sequence that results in sickle-cell anemia, shows a substitution of an A for the middle T. This leads to GUA in the messenger RNA, which specifies the amino acid valine. The substitution of valine for glutamic acid at this particular position alters the chemistry of the hemoglobin such that it sticks together if it is not binding oxygen, creating sickling of the red blood cells.