(a) (i) A – Dendrite, B – Axon
(ii) The information in the neuron is acquired at the end of the dendrite tip.
(iii) The information travels from the dendrite to the cell body and then along the axon to its end.
(iv) The information travels in the form of an impulse.
(v) The impulse is converted into a chemical signal at the end of the axon.
(b) Thyroxine hormone is secreted by thyroid. Function of Thyroxine hormone : It regulates carbohydrate, protein and fat metabolism in the body so as to provide the best balance for growth. The use of iodised salt is advisable because iodine is essential for the synthesis of thyroxin. In case of iodine deficiency in our diet, there is a possibility one can suffer from goitre, which is a disease of swollen neck.