... The choice of a hornwort Anthoceros is substantiated by such advantages as the feasibility of simultaneous measurements of the chloroplast membrane potential, the electric potential changes at the cell membrane, and changes in chlorophyll fluorescence parameters occurring upon the absorption of photosynthetically active radiation (PAR). ... A remarkable property of Anthoceros cells is an electrical excitation of the plasma membrane in response to light pulses with a length of few seconds. ...