Organism A has more juxtamedullary nephrons than organism B. Which of these organisms could concentrate urine more effectively and why?
To determine which organism could concentrate urine more effectively, we need to understand the role of juxtamedullary nephrons in urine concentration.
Juxtamedullary nephrons are a type of nephron found in the kidneys. They play a crucial role in concentrating urine by creating a concentration gradient in the kidney tissue. These nephrons have longer loops of Henle that extend deep into the medulla (the inner part of the kidney).
By having more juxtamedullary nephrons, Organism A is better equipped to concentrate urine effectively. The longer loops of Henle allow for greater water reabsorption and concentration of solutes in the urine. This is important in conserving water and maintaining fluid balance, especially in environments where water availability is limited.
On the other hand, Organism B, with fewer juxtamedullary nephrons, would have a reduced ability to concentrate urine efficiently. The shorter loops of Henle would limit the extent of water reabsorption and solute concentration in the collecting ducts, resulting in less concentrated urine being produced.
In summary, Organism A, with more juxtamedullary nephrons, could concentrate urine more effectively than Organism B due to the increased capacity for water reabsorption and solute concentration in the nephrons.