Answer:
glycoproteins
Explanation:
Glycoproteins are the proteins to which carbohydrates are attached. The glycocalyx is the covering made up of sugar residues of glycoproteins and glycolipids and is associated with the plasma membrane.
Glycoproteins of animal cells are exposed to the extracellular surface and are involved in cell recognition. They serve as a tag by which the cells are identified. For example, the glycoproteins of bacterial cells serve as antigens that are recognized by the cells of the immune system of humans. However, these cells recognize the glycoproteins present on the cells of own body as "Self". Likewise, specific glycoproteins present on the surface of RBCs determine the blood type as A, B, AB or O.
Answer:
A. Books and DVDs can be given new life as well.
Having too much matter causes the star to explode, resulting in a supernova. As the star runs out of nuclear fuel, some of its mass flows into its core. Eventually, the core is so heavy that it cannot withstand its own gravitational force. The core collapses, which results in the giant explosion of a supernova