Answer to Question 1
Every living cell contains iron. Bound into the protein hemoglobin in the red blood cells, it helps transport oxygen from lungs to tissues and thus permits the release of energy from fuels to do the cells' work. When the iron supply is too low, iron-deficiency anemia occurs, characterized by weakness, tiredness, apathy, headaches, increased sensitivity to cold, and a paleness that reflects the reduction in the number and size of the red blood cells. A person with this anemia can do very little muscular work without disabling fatigue, but can replenish iron status by eating iron-rich foods.
Iron deficiency is the most common and widespread nutritional disorder in the world. People begin to feel the impact of iron deficiency, without knowing it, long before anemia is diagnosed. They do not appear to have an obvious deficiency disease; they just appear unmotivated and apathetic. Because they work and play less, they are less physically fit. In the United States, iron deficiency remains relatively prevalent among toddlers, adolescent girls, and women of childbearing age.
Answer to Question 2
A
The circulatory system plays a central role in thermoregulation by the moth, Manduca sexta
Stony-Iron Meteorite
Symptoms of anaphylaxis
In pretend play, toy figures and animals “come to life” and interact with each other.
Purpura, an inflammation of the blood vessels.
White blood cells