BIOLOGY
HORMONES
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Because target cells contain no receptors
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Only target cells contain receptors for aldosterone
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Either A or B
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None of the above
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Detailed explanation-1: -Steroid hormones are lipophilic. They cross the cell membrane but can function only when they bind to specific receptors that are present only in the target cell. The hormone-receptor complex then binds to regions of DNA and activates transcription of that particular region of DNA.
Detailed explanation-2: -Classical aldosterone target tissues are kidney, colon, sweat and salivary glands.
Detailed explanation-3: -Aldosterone acts in the body by binding to and activating a receptor in the cytoplasm of renal tubular cells. The activated receptor then stimulates the production of ion channels in the renal tubular cells. It thus increases sodium reabsorption into the blood and increases potassium excretion into the urine.
Detailed explanation-4: -Aldosterone is a mineralocorticoid that regulates sodium and potassium balance in its target tissues (kidney, colon, salivary gland).
Detailed explanation-5: -Hormones work by binding to protein receptors either inside target cells or on their plasma membranes. The binding of a steroid hormone forms a hormone-receptor complex that affects gene expression in the nucleus of the target cell.