Cuboidal epithelium with brush border of microvilli is found in:

Which process is responsible for the excretion of drugs and toxins from the blood into the filtrate?

Which of the following statements is correct regarding the reabsorption of $K^+$ (Potassium) in the nephron?

Which of the following statement$(s)$ is/are true?
$(1)$ Urine is hypertonic in the distal convoluted tubule.
$(2)$ When the urine passes into the collecting tubule,it becomes hypotonic.
$(3)$ Urine is isotonic in the proximal convoluted tubule.
$(4)$ Urine becomes more and more hypotonic as it passes through Henle's loop.

Which one of the following substances is actively secreted into the glomerular filtrate of the kidney tubule?

Draw a labelled diagram showing reabsorption and secretion of major substances at different parts of the nephron.