2. The endosymbiotic theory suggests that a eukaryotic cell is the result of one prokaryotic cell eating another.
Fossilized non-seed vascular plants from the Devonian period have been identified.
<span>The Devonian is an early period and conformity of the Paleozoic Epoch forming from the edge of the Silurian Era.</span>
Answer:
The correct order, from fastest to slowest, for the passage of molecules and ions through the cell membrane is oxygen, sodium ions, glucose (option D).
Explanation:
The plasma membrane is a lipid bilayer, with glycoproteins and membrane proteins, which constitutes a semi-permeable barrier to the passage of substances into and out of the cell.
The speed with which a substance can pass through the membrane depends on its chemical properties -hydrophilic substances pass through with greater difficulty than lipophilic ones- requiring in some cases specialized transport mechanisms. The different rates with which a substance passes depends on this.
- <em>Oxygen (O₂) </em><em>passes through simple diffusion, depending on a concentration gradient. It's the molecule that passes through the membrane the fastest.
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- <em>In second place, there would be the </em><em>Na⁺ ions</em><em> -charged atoms- that cross the membrane by facilitated diffusion, through specific ionic channels.
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- <em>The </em><em>glucose</em><em> molecule, being larger, requires the use of transport proteins, being its passage through the membrane slower with respect to oxygen or sodium.</em>
Undoubtedly, molecular weight and affinity for the plasma membrane are determining factors for the passage of molecules through the lipid bilayer.
Learn more:
Simple diffusion and active transport brainly.com/question/6420224
Answer:
a pore, found in the epidermis of leaves, stems, and other organs, that facilitates gas exchange. The pore is bordered by a pair of specialized parenchyma cells known as guard cells that are responsible for regulating the size of the stomatal opening.
Explanation:
<em>Answer:</em>
<em>The answer for this statement is "True".</em>
<em>Explanation:</em>
<em>In the kidneys, the countercurrent mechanism involves the interaction between the flow of filtrate through the loop of Henle of the juxtamedullary nephrons (the countercurrent multiplier) and the flow of blood through the limbs of adjacent blood vessels (the countercurrent exchanger). This relationship establishes and maintains an osmotic gradient extending from the cortex through the depths of the medulla that allows the kidneys to vary urine concentration dramatically which is true.</em>
