(a)[5]
The passage below explains how sensory receptors function. Complete it by inserting the most suitable scientific term(s). A sensory receptor cell reacts to a stimulus by opening ion __________ in its cell surface membrane. Sodium ions move into the cell causing the membrane to become __________. This is called the __________ potential. If this potential is large enough to reach a __________ then an action potential is transmitted to the central nervous system. As stimulus strength increases, the __________ of action potentials transmitted increases.
(b)[5]
Describe how an action potential is transmitted along a sensory neurone in a mammal.