on channel-linked receptors, G-protein-linked receptors, and enzyme-linked receptors.
The ability of cells to communicate through chemical signals originated in single cells and was essential for the evolution of multicellular organisms. In multicellular organisms, cells send and receive chemical messages constantly to coordinate the actions of distant organs, tissues, and cells. Cells can receive a message, transfer the information across the plasma membrane, and then produce changes within the cell in response to the message. Single-celled organisms, like yeast and bacteria, communicate with each other to aid in mating and coordination. Cellular communication has developed as a means to communicate with the environment, produce biological changes, and, if necessary, ensure survival.
The answer is spicules. These
sharp-pointed structures are formed from calcium carbonate skeleton of
the organisms. They can also be formed from silica. They can be big (megascleres),
or microscopic (microscleres). Also dependent on the number of axis on the spicules, they are classified as monoaxon,
triaxon or polyaxon.
I am a mycologist. A person who studied biology major mycology. Mycology is the study of fungi. An expert in fungi's genetic and biochemical makeup, pathogen, and taxonomy. I also study benefits and usage in humans as food and medicine together with the innate danger and poisons.