This picture shows normal blood cells, which are round, and sickle cells, which appear much longer. people with sickle cells suffer from sickle cell anemia, which is an inherited disease. it is caused by a change in a gene responsible for production of hemoglobin. this type of change is known as a(n)

The correct answer is-

Mutation.

Mutation can be described as the permanent change in the genetic material ( DNA, deoxyribonucleic acid) of living organisms.

Sickle cell anemia is a genetic disorder that is caused by mutation in the gene for beta globin chain ( that is component of oxygen carrying molecule, hemoglobin) that leads to replacement of glutamic acid by valine at the sixth position. This results in abnormal hemoglobin ( sickle shaped) that affects the transport of oxygen throughout body.