(a(i))[2]
State the domain and kingdom that the golden mantella is classified in.
(a(ii))[1]
The golden mantella has brightly coloured skin and a toxin. Suggest one advantage to the frog of having bright colouration.
(b)[3]
The toxin in the skin of the golden mantella influences the action of sarcomeres in muscle fibres (muscle cells) of mammalian striated muscle. The toxin blocks a protein, $\text{Ca}^{2+}\text{ATPase}$, located in the membrane of the sarcoplasmic reticulum. $\text{Ca}^{2+}\text{ATPase}$ transports calcium ions from the cytoplasm into the sarcoplasmic reticulum when the fibre is no longer being stimulated. Suggest the effects on the sarcomere of the action of the golden mantella toxin.
(c)[3]
Describe the function of calcium ions in a cholinergic synapse.