Question

Read the assertion and reason carefully to mark the correct option in question.

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.

Answer 1

Assertion
Aldosterone a mineralocorticoid hormone secreted by the cortex of of adrenal gland. It helps in maintaining the sodium and potassium ions in the blood and plasma respectively.

Reason
The sodium ion concentration is increased by absorbing into renal tubules and lowers the concentration of potassium ions. Hence the reason is correct explanation of assertion.

Accessory Excretory Organs
The intestine excretes out the digestive wastes. The liver secretes bilirubin, biliverdin, cholesterol, degraded steroid hormones, vitamins and drugs that are eventually passed down in the urine.

Thus these organs assist in some way in the excretion of waste substances of our body.