Answer:
The correct answer is - higher than
Explanation:
In the lumen of the proximal tubule of the kidney, most of the solutes are absorbed in the form of sodium. There is a gradient of sodium ions which allows the absorption of the solutes from the lumen into the cell.
It is due to the solute or Na concentration is higher in the lumen than Na concentration inside the cells of the tubule wall. So movement of the solutes is due to the concentration gradient.
The correct answer among the choices listed above is option D. The connection between the mother and the embryo that provides the embryo with oxygen and nutrients and waste disposal is the placenta. Hope this answers your question. God Bless.
Root hairs are important to a plant because they increase the surface area for absorption. i really hope this helps.