To create a mysterious mood.
The cell in the stomata. The cell is called the mesophyll which can be broken down in two layers the palisade layer and the spongy layer.
I believe that secretion into the tubular fluid occurs when the principle cells in the Proximal convoluted tubule secrete H+ into the urine.
Tubular secretion is the transfer of materials from peritubular capillaries to the renal tubular lumen; it is the opposite process of reabsorption. This secretion is caused mainly by active transport and passive diffusion.
Answer:
the answer is all of these
