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.

2%? i tried finding the exact sorry if it's not 100% correct ; -;

cells use diffusion to get substances in and out of themselves. that diffusion will occur across the cell membrane or the outer covering of the cell. because we are talking about the surface of the cell, surface area and volume are  important factors here. as a cell increases in size, its surface area and volume increase as well.  we call that the surface area to volume ratio (sa: vol).  but the catch is that  volume increases at a greater rate than surface  area. in other words, as a cell gets bigger, the sa: vol gets smaller. so a really small cell like bacteria is mostly cell membrane (surface) with very little contents (volume). a really big cell like an egg, is mostly insides with a super thin membrane. so what ends up happening is that the cell cannot efficiently diffuse all of the stuff it needs in/out to survive. therefore cell size is limited to about 100mm. so how do we make organisms bigger than 100mm? cells divide! by dividing and becoming multicellular, organisms are able to grow!   check out the diagrams i attached to see the effect of sa: vol. i hope this ! good luck!