How would the absence of juxtamedullary nephrons affect the volume of urine and its osmotic concentration?

Increase volume; decrease osmotic concentration

Explanation:

Nephron is the functional unit of a kidney.

The juxtamedullary nephrons is responsible for the development of the osmotic gradients. The osmotic gradient helps in ensuring the urine is well concentrated and helps in adequate water reabsorption.

The absence of juxtamedullary nephrons affect the volume of urine and its osmotic concentration by Increasing the volume and decreasing the osmotic concentration.

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the dead sea, the lowest place on earth at 430 metres (1,410 ft) below sea level, has a correspondingly high typical atmospheric pressure of 1065 hpa.