Question

read the passage. two kinds of iron the human body needs iron to produce hemoglobin, a substance that helps red blood cells transport oxygen. without enough iron, a person may feel tired and weak. dietary sources of iron include plant sources, such as vegetables and beans, and animal foods, including poultry, red meat, and fish. however, plant and animal sources are not equal. the iron in plants, called nonheme iron, is not easily absorbed by the human digestive system. for example, a half cup of cooked spinach contains a healthy dose of over three milligrams of iron. unfortunately, only five percent of that iron can be used by the body. on the other hand, the iron in animal foods, called heme iron, is better utilized. heme iron is contained within a ring of protein, which helps the body to absorb it easily. what is the main, or central, idea of the passage? plant and animal food sources both contain iron, but the iron in animal foods is more accessible to the body. plant and animal food sources both contain iron, which helps red blood cells carry oxygen throughout the body. heme iron, found in meat and fish, is easily absorbed by the human body.

Explanation:

The passage first states that the human body needs iron for hemoglobin - related oxygen - transport. It then mentions plant and animal food sources of iron. The key is to note the contrast between non - heme iron in plants (less absorbable) and heme iron in animals (more absorbable). The main idea should capture this contrast.

Answer:

Plant and animal food sources both contain iron, but the iron in animal foods is more accessible to the body.