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Why is blood red?
Each hemoglobin protein is made up subunits called hemes, which are what give blood its red color. More specifically, the hemes can bind iron molecules, and these iron molecules bind oxygen.
What are red blood cells?
The main job of red blood cells, or erythrocytes, is to carry oxygen from the lungs to the body tissues and carbon dioxide as a waste product, away from the tissues and back to the lungs. Hemoglobin (Hgb) is an important protein in the red blood cells that carries oxygen from the lungs to all parts of our body.
How are red blood cells created?
Production of red blood cells is controlled by erythropoietin, a hormone produced primarily by the kidneys. Red blood cells start as immature cells in the bone marrow and after approximately seven days of maturation are released into the bloodstream.
How is oxygen transported in blood?
The red blood cells contain a pigment called haemoglobin, each molecule of which binds four oxygen molecules. Oxyhaemoglobin forms. The oxygen molecules are carried to individual cells in the body tissue where they are released.
What is anemia?
a condition marked by a deficiency of red blood cells or of hemoglobin in the blood, resulting in pallor and weariness.
What are the symptoms of anemia?
Symptoms common to many types of anemia include the following:Easy fatigue and loss of energy.Unusually rapid heart beat, particularly with exercise.Shortness of breath and headache, particularly with exercise.Difficulty concentrating.Dizziness.Pale skin.Leg cramps.Insomnia.
Can anemia go away?
Your iron deficiency anemia symptoms should start to go away after about a week of taking iron supplements. Your doctor will check your blood to see if it has improved.

Question: What are its possible causes
Self-contained rewrite: What are anemia's possible causes?