1: Photo receptor cell
Ex: This cell uses light for energy in vertebrates and it uses the energy for its purpose making the vertebrate survive.
https://en.wikipedia.org/wiki/Cone_cell
https://en.wikipedia.org/wiki/Cone_cell
2: Nerve Cell
Ex: http://www.sparknotes.com/testprep/books/sat2/biology/chapter9section1.rhtml
This cell stimulates and controls the nerves of the cells and allows the body to feel pain.
This cell stimulates and controls the nerves of the cells and allows the body to feel pain.
3: This is a tissue cell
Ex: This cell is the organised unit for the cell. It controls everything the cell does and its actions involved.
http://www.sci-books.org/biology/biology-of-the-vertebrates/biology-of-the-vertebrates-units-of-structure-cytology.shtml
http://www.sci-books.org/biology/biology-of-the-vertebrates/biology-of-the-vertebrates-units-of-structure-cytology.shtml