Answer:
Red blood cells.
Explanation:
Our blood is made up of blood cells and plasma which is an aqueous fluid. Blood type is determined by the identifiers presence and absence which is present on the surface of red blood cells. These identifiers are known as antigens which helps in the immune system to identify its own red blood cell types.
There are 4 types of blood type:
A, B, O, and AB. These blood types are determined with the help of the antigen which is present on the surface of the blood cell and antibodies which is present in the plasma.
D) all of the above is the correct answer
Answer:
Due to their hole size.
Explanation:
Some molecules can pass directly through the phospholipid bilayer because of their small size which can easily pass through the small holes of phospholipid bilayer, while those that are too large or too charged need to pass through a membrane protein because membrane protein has a large holes through which large molecules can easily pass through the semi-permeable membrane of the cell by active or passive transport.