Indicate whether the following statements are true of false : (a) Both auricles of amphibian heart open into the same ventricle.
(b) Prawn's heart carries only oxygenated blood.
(c ) Purkinje fibres are nerve fibres supplying the ventricular muscles.
(d) The first heart sound results from a closure of semilunar valves.
(e ) The vagus nerve reduces the heart rate.
(f) The A-V node normally initiates the cardiac impulse.
(g) Semilunar valves open during the ventricular diastole.