GROWTH DEVELOPMENT CHILD
GROWTH AND DEVELOPMENT
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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The nucleus has instructions to turn some genes on and some genes off.
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Signals from chemicals in the organism or from the environment determine which genes will be turned on and off.
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Genes turn on and off randomly.
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The cell has unique DNA that determines what the cell will become.
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Detailed explanation-1: -Signals from the environment-chemicals, extracellular proteins/hormones/factors, neighboring cells, the physical environment-converge on the cell, typically activating a signaling cascade that leads to gene expression. These specific proteins change the phenotype into that of a more specialized cell.
Detailed explanation-2: -Stem cell differentiation involves the changing of a cell to a more specialized cell type, involving a switch from proliferation to specialization. This involves a succession of alterations in cell morphology, membrane potential, metabolic activity and signal responsiveness.
Detailed explanation-3: -Embryonic cells are provided with signals that indicate their location in the body. These signals turn gene expression on or off in that cell, causing it to differentiate into a cell appropriate to its location.
Detailed explanation-4: -Q. How do stem cells know what type of cells to differentiate into? The nucleus has instructions to turn some genes on and some genes off. Signals from chemicals in the organism or from the environment determine which genes will be turned on and off.