histone / histones. Under the microscope in its extended form, chromatin looks like beads on a string. The beads are called nucleosomes. Each nucleosome is made of DNA wrapped around eight histone proteins that function like a spool and are called a histone octamer.he beads are called nucleosomes. Each nucleosome is made of DNA wrapped around eight histone proteins that function like a spool and are called a histone octamer.
Definition. A hemoglobin test measures the amount of hemoglobin in your blood. Hemoglobin is a protein in your red blood cells that carries oxygen to your body's organs and tissues and transports carbon dioxide from your organs and tissues back to your lungs. If a hemoglobin test reveals that your hemoglobin level is lower than normal, it means you have a low red blood cell count (anemia). Anemia can have many different causes, including vitamin deficiencies, bleeding and chronic diseases.
Hemoglobin is the main ingredient in red blood cells. Hemoglobin helps red blood cells carry oxygen from the lungs to other parts of the body. Normal red blood cells have hemoglobin A. People with hemoglobin D trait have red blood cells that have normal hemoglobin A and an abnormal hemoglobin.