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jeyben [28]
2 years ago
12

What technological advancement was necessary before scientists could begin to observe cells?

Biology
2 answers:
VLD [36.1K]2 years ago
5 0
Yeah thats correctomundo
Lady bird [3.3K]2 years ago
4 0
The microscope. Scientists were able to observe tiny parts of cells since they are not visible to the naked eye.
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By binding to DNA it triggers the transcription of a specific  gene.
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If a molecule is to large or polar and cannot easily diffuse into the cell, it is
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hydrophilic

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Large polar or ionic molecules, which are hydrophilic, cannot easily cross the phospholipid bilayer. Charged atoms or molecules of any size cannot cross the cell membrane via simple diffusion as the charges are repelled by the hydrophobic tails in the interior of the phospholipid bilayer.

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A DNA molecule produced by combining DNA from different sources is known as
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Answer:

A DNA molecule produced by combining DNA from different sources is known as recombinant DNA.​

Explanation:

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The other options are not correct because:

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Cells in a large multicellular organism communicate with each other by chemical signals. These signals are passed from one cell
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Answer:

Cells in a large multicellular organism communicate with each other by chemical signals. These signals are passed from one cell to another. To receive and respond to a chemical signal, a cell must have a <u><em>receptor</em></u> for that chemical.

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To generate a physiological response, all cells in the body have special proteins called receptors. These receptors are involved in detecting a chemical signal and generating a response. The receptors are specific for different kind of chemical signals. For example, a dopamine receptor will bind a dopamine molecule whereas an insulin receptor will be able to bind an insulin molecule. Apart from chemical signals, some cells might also respond to mechanical signals.

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