Assertion : Aldosterone is a steroid hormone and is important in the control of sodium and potassium ion concentration in mammals.

Reason : It upgrades sodium ion concentration in the ECF by promoting reabsorption of sodium ions from renal tubules and excretion of potassium ions in urine.

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false

• If both assertion and reason are false

A.

If both assertion and reason are true and reason is the correct explanation of assertion

Aldosterone is a steroid hormone or mineralocorticoid produced by the outer-section ie, zona glomerulosa of the adrenal cortex in the adrenal gland to regulate sodium and potassium balance in the blood. It is produced in the cortex of adrenal gland (above the kidneys). It helps in regulating blood pressure. It sends signals to the organs like kidney and colon, that can increase the amount of sodium that the body sends into the blood stream or the amount of potassium released in the urine. It also helps to maintain body's pH and electrolyte levels.