Why is the use of iodised salt advisable

Question

(i) Why is the use of iodised salt advisable?
(ii) Label the parts (a), (b), (c) and (d) and show the direction of flow of electrical signals in the figure.

Answer 1

(i) Iodine is necessary for the thyroid gland to make the hormone thyroxine. Thyroxine regulates carbohydrate, protein and fat metabolism in the body to provide balance for growth. Deficiency of iodine can lead to goitre.
(ii) (a) Sensory neuron
(b) Spinal cord (CNS)
(c) Motor neuron
(d) Effector—muscle in arm Flow of electrical signals: Receptors in hand ⇒ Sensory neurons ⇒ Spinal cord (CNS) ⇒ Motor neurons ⇒ Effector – muscles in arm.