The hormone aldosterone, which acts on the distal convoluted tubule and collecting duct to increase sodium reabsorption and potassium excretion, is secreted by the: MCQ with Answer and Explanation
The hormone aldosterone, which acts on the distal convoluted tubule and collecting duct to increase sodium reabsorption and potassium excretion, is secreted by the:
A. Zona fasciculata of the adrenal cortex
B. Anterior pituitary
C. Adrenal medulla
D. Zona glomerulosa of the adrenal cortex
Answer: Option D
Solution (By JKSSB Mock Tests)
Aldosterone is a mineralocorticoid hormone secreted by the zona glomerulosa, the outermost layer of the adrenal cortex. Its primary function is to regulate electrolyte balance by promoting the active reabsorption of sodium (Na+) and the excretion of potassium (K+) and hydrogen ions (H+) in the distal tubules and collecting ducts of the kidneys. The zona fasciculata secretes glucocorticoids (cortisol).
Explanation:
The liver is the primary organ for glycogenesis (storing glucose as glycogen) and glycogenolysis, maintaining blood glucose levels. Muscles store glycogen for local use. Pancreas regulates via hormones, kidneys excrete excess glucose.
Explanation:
In roots, the protoxylem (first formed xylem) lies towards the periphery and metaxylem towards the centre; this arrangement is called exarch. In stems, protoxylem is towards the centre, called endarch. Exarch condition is typical of roots. Mesarch is found in ferns. This arrangement aids in understanding anatomical differences between root and stem.
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