Q.Kidney of frog is

Step 1. Vertebrate kidneys are classified into three types by their developmental and structural complexity - pronephros (simplest, embryonic), mesonephros (intermediate), and metanephros (most advanced, seen in reptiles, birds and mammals).

Step 2. The frog's paired kidneys are explicitly described as mesonephric, situated on either side of the vertebral column and packed with numerous nephrons. …

Recall which of the three vertebrate kidney types (pronephros/mesonephros/metanephros) …

• Confusing the frog's mesonephric kidney with the metanephric kidney of birds and reptiles, covered later in the same chapter for the pigeon. …