open the mechanical actuator lock. flashing light indicating the gate movement on the housing. it shall have a built - in antenna, mhz radio receiver & support for surface wall - mounting. modulated infrared ray photocells. weather-proof and mechanically resistant outside container. pair of photo cells...
of the tracheoles contain fluid. it is where the fluid and gas meet (= the fluid/gas interface), that exchange of gases occurs (oxygen is taken up, carbon dioxide is given off). as activity increases, the fluid is removed from the tracheoles. this means that the exchange of gases occurs nearer the cells...