Answer:
The body's cells use oxygen for metabolism, and this process creates the waste product carbon dioxide. With the help of the lymphatic and circulatory systems, the skeletal system works with the respiratory system by creating red blood cells in the bones that aid in respiration facilitated by the lungs.
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.
Structurally speaking, RNA and DNA are different. One clear distinction between the two is that RNA is single stranded, while DNA is double stranded. Another way they differ is found in their nitrogen bases. The four bases for DNA are Adenine, Thymine, Cytosine, and Guanine (think, ATCG). The bases for RNA are the same, except Thymine is replaced with Uracil (think, AUCG).
Another note is that RNA polymerase is unable to detect errors in base pairings, unlike DNA polymerase, but their syntheses are both in the 5’3’ direction. Hopefully this helps you answer this question.
A directional movement of water is ocean currents