Answer: Small palpebral fissures, Small jaw, and Thin upper lip.
(Options: A, B, & C)
~Hope this helps!
In most mammals, hemoglobin consists of 4 distinct subunits. These subunits consist of an aminoacid chain (aminoacids are the building blocks of proteins) and a heme group. 2 of the subunits have a protein chain with a-structure and 2 have a protein chain with beta structure. The heme groups give hemoglobin and thus blood its red color. Each of these groups has a positively charged iron ion in its core. Iron is necessary so that hemoglobin can bind oxygen and transfer it through the blood flow to the tissues. Given the above exposition, the correct answers are: 4, alpha proteins, heme, iron, oxygen.
Bonus: Hemoglobin is an important example of protein structure since it shows that not only aminoacid order (secondary structure) and configuration of protein chains (tertiary structure) are crucial to the function of a protein; how the multiple chains bind to each other is equally critical (quaternary structure).
You said which, so there should be choices.
The answer is; A
Nebulae are clouds of dust and gas in space. When local areas in nebulae start to collapse under their own weight and fusion begins, a star is born. This, therefore, means that a star is denser than nebulae because it requires that atoms fuse for it to form. Fusion creates heavier atoms from light atoms.
