ANIMAL PHYSIOLOGY
CHEMICAL SIGNALS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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They would be unable to respond to hormone signals in the bloodstream
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They would be unable to grow and divide in response to signals from nearby cells
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They would bind to locally secreted growth factors & intracellular pathways would be blocked
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They would grow and divide normally
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Detailed explanation-1: -Which of the following is most likely fate of animal cells that lack receptors for local paracrine signal molecules? They would be unable to grow and divide in response to growth factors from nearby cells.
Detailed explanation-2: -Nitric oxide (NO) acts as a paracrine signal that affects only neighboring cells because: It is rapidly converted to nitrates and nitrites in the extracellular fluid. Nitric oxide (NO) causes blood vessels to dilate because: it causes smooth muscle cells in the walls of blood vessels to relax.
Detailed explanation-3: -In paracrine signaling, a molecule released by one cell acts on neighboring target cells.
Detailed explanation-4: -Hydrophobic signaling molecules typically diffuse across the plasma membrane and interact with intracellular receptors in the cytoplasm. Many intracellular receptors are transcription factors that interact with DNA in the nucleus and regulate gene expression.
Detailed explanation-5: -Why do signaling molecules only induce a cellular response in particular cell types (Target Cells) and not in all cells? The cellular response to a particular extracellular signaling molecule depends on its binding to a specific receptor protein located on the surface of a target cell or in its nucleus or cytosol.