What characteristic change occurs to normoblasts as they mature?

As normoblasts mature into erythrocytes, one of the significant changes is a decrease in adhesion receptor expression. This process is crucial for the transition from a developing red blood cell to one that can effectively move into circulation. In the early stages of erythropoiesis, normoblasts display adhesion receptors that help them interact with the bone marrow microenvironment. However, as they mature, they need to detach and migrate into the bloodstream, where adhesion is no longer required.

The decrease in adhesion receptor expression facilitates this transition, ensuring that once they are fully matured, the erythrocytes can function efficiently in oxygen transport without the need for the interactions that were necessary during their development.

Additionally, while the other choices refer to changes that take place during normoblast maturation, they do not accurately describe the key transitions involving adhesion receptors and migration. The decrease in adhesion receptor expression is fundamental to the maturation process and the functionality of mature erythrocytes in the bloodstream.