I think its the left one (sorry if im wrong)
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.
Only the birds with the largest of beaks are able to eat the toughest, biggest, and spine covered seeds. Which is not right because some other Galapagos Birds might have some other way eat those seeds with their finches