Organism A has more juxtamedullary nephrons than organism B. which of these organisms could concentrate urine more effectively and why?
http://en.wikipedia.org/wiki/Juxtamedullary_nephron
To determine which organism, A or B, could concentrate urine more effectively, we first need to understand the role of juxtamedullary nephrons in urine concentration.
Juxtamedullary nephrons are a type of nephron found in the kidneys, responsible for concentrating urine. These nephrons have long loops of Henle that extend deep into the medulla of the kidney.
Now, let's compare the two organisms:
Organism A has more juxtamedullary nephrons. Since these nephrons can extend deep into the medulla, they have a greater ability to create a concentration gradient in the kidney. This gradient is essential for concentrating urine because it allows for the reabsorption of water from the filtrate.
On the other hand, Organism B has fewer juxtamedullary nephrons. With fewer of these nephrons, the ability to establish a strong concentration gradient may be limited.
Based on this information, we can conclude that Organism A, with more juxtamedullary nephrons, would be able to concentrate urine more effectively. The greater number of juxtamedullary nephrons would provide a larger surface area for reabsorption of water and allow for a stronger concentration gradient.
It's important to note that other factors may also influence urine concentration, such as hormonal regulation and overall kidney function. Nonetheless, in terms of juxtamedullary nephrons, Organism A would have the advantage in concentrating urine more effectively.