Final answer:
The statement is true; during tubular reabsorption in the nephron, all needed solutes are reabsorbed along with most water from the filtrate, primarily occurring in the proximal convoluted tubule and the loop of Henle.
Step-by-step explanation:
The statement that in tubular reabsorption, all needed solutes and most water that formed the filtrate are reabsorbed into the nephron is true. Tubular reabsorption is a crucial process in the kidneys during which filtered substances are reclaimed from the filtrate back into the blood. This occurs primarily in the proximal convoluted tubule (PCT) and loop of Henle. In this phase, about two-thirds of the filtered salts and water as well as all of the filtered organic solutes such as glucose and amino acids are reabsorbed. Sodium (Na+), the most abundant ion in the filtrate, is actively reabsorbed, and because of osmotic pressure gradients, water follows the sodium ions through aquaporins present in the PCT.
Moreover, the tubular reabsorption is regulated and can be influenced by hormones, especially when the filtrate reaches the distal convoluted tubule (DCT), where conditions such as the body's need for water can trigger additional reabsorption.