In humans, red blood cells contain hemoglobin, which is an oxygen-binding protein. Hemoglobin helps provide oxygen to the body’s tissues. Each molecule of hemoglobin is made up of four subunits. The human genome encodes multiple variations of the hemoglobin subunit, including the alpha, beta, and gamma chains. The specific subunits that make up the dominant form of hemoglobin in a person’s body are determined by the person’s age and genetic background.The hemoglobin that is present in a fetus, or fetal hemoglobin, has a different functional profile than the hemoglobin present after birth, which is called adult hemoglobin. This difference can be seen in Figure 1, which shows how strongly each type of hemoglobin binds to oxygen.The x axis is labeled Oxygen partial pressure with increments increasing by 40 and marked at zero, 40, 80, and 120. The y axis is labeled percent saturation with markings at zero, 50, and 100. There are 2 lines labeled on the graph. A solid line is labeled fetal hemoglobin, and a dotted line labeled adult hemoglobin. Both lines begin at 0,0. The fetal hemoglobin rises sharply from 0,0 and peaks at 40, 100. The fetal hemoglobin line then flattens out and remains at 100 percent saturation across the x axis. The adult hemoglobin line is shifted to the right. It begins at 0,0 and rises to reach a peak at 80, 100. The adult hemoglobin line then flattens out and remains at 100 percent saturation across the x axis.Figure 1. Oxygen dissociation curves for fetal and adult hemoglobin. The curve for fetal hemoglobin is shifted to the left compared to the curve for adult hemoglobin, indicating that fetal hemoglobin has a higher affinity for oxygen.Both adult and fetal hemoglobin contain alpha chain subunits. According to the information provided, which of the following diagrams is the most likely representation of fetal and adult hemoglobin?Images of 3 subunits of hemoglobin. One image is colored red and labeled alpha chain, one image is colored gray and labeled beta chain, and the third image is colored orange and labeled gamma chain.Choose 1 answer:Choose 1 answer:(Choice A)   A(Choice B)   B(Choice C)   C(Choice D)   D