Receptors that are embedded on the cell membrane bind to chemicals outside of the cell and this binding process cause a chemical response on the inside of the cell.
These receptors that help in communication between the cell and the outside world are called cell surface receptors or sometimes transmembrane receptors.
A majority of chemical signals are water soluble thus unable to cross the fatty lipid bi-layer of the cell membrane. Their receptors, which are protein in nature therefore must span the membrane, detect their presence outside of the cell and transmit this information into the interior of the cell.
White Blood Cells (WBC), produced by the stem cells found in the bone marrow, manufacture antibodies used to counter the effects of the antigens.
The White Blood Cells are known to provide immunity to the body against foreign bodies like bacteria, virus, proteins, etc. The lymphocyte cells, namely, the B-cells and T-cells are the two key cells that make antibodies for various antigens and kill or lyse the foreign body by recognising the antibiotic marker attach to them.
Crocodiles and birds I think
The water gets inside the cell and it looks like its going to burst...the weight will be heavier
