Answer:
B. The membrane lets certain substances move across it freely, while others must move through a “gate”.
Explanation:
Selective permeability is a property of cellular membranes that only allows certain molecules to enter or exit the cell. This is important for the cell to maintain its internal order irrespective of the changes to the environment. For example, water, ions, glucose and carbon dioxide may need to be imported or exported from the cell depending on its metabolic activity. Similarly, signaling molecules may need to enter the cell and proteins may need to be released into the extracellular matrix. The presence of a selectively permeable membrane allows the cell to exercise control over the quantum, timing and rate of movement of these molecules.
Earth's atmosphere is 78%<span> nitrogen </span>21%<span> oxygen, </span>0.9%<span> argon, and </span>0.03%<span> carbon dioxide with very small percentages of other elements.
hope it helps</span>
The layer of the sun is in three equally side the sun the moon and the galaxy
Answer:
<em>The correct option is C) OH</em>
Explanation:
In the field of chemistry, radicals can be described as atoms, molecules or ions which have at least one unpaired electron.
The formation of a radical occurs when a single covalent bond breaks so that each of the atoms that had been involved in the formation of the covalent bond can have an unpaired electron. Examples of radicals include OH, NH4+ etc.
Other option, like option B, is not true because a molecule of water does not have any unpaired electrons in its valence shell.
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Which is an adaptation?A. A dog is trained to catch a ball.
B. A person learns how to do math.
C. A rabbit has fur that blends in with snow
D. A bird breaks its wing in an accident.
C. A rabbit has fur that blends in with snow
