This means that it only allows for select materials to be able to move across it and not all molecules and other substances floating in the external environment. The proteins and the phospholipid Bilayer help to contribute the selectivity of the membrane.
Answer;
Hemoglobin
Explanation;
-Hemoglobin is the protein molecule in red blood cells that carries oxygen from the lungs to the body's tissues and returns carbon dioxide from the tissues back to the lungs.
-Hemoglobin is made up of four protein molecules (globulin chains) that are connected together.
- Hemoglobin also plays an important role in maintaining the shape of the red blood cells. In their natural shape, red blood cells are round with narrow centers resembling a donut without a hole in the middle. Abnormal hemoglobin structure can, therefore, disrupt the shape of red blood cells and impede their function and flow through blood vessels.
A decomposer breaks down the cells of a dead organism .
What graph? show a picture please.