To which class does Ichthyophis belong?

What does not open into the cloaca in amphibians?

Tympanum represents ear in $-$

Mixing of oxygenated and deoxygenated blood occurs in the heart of

Which animal possesses a three-chambered heart consisting of two atria and one ventricle?

Which of the following is $NOT$ true for the $Axolotl$ larva?
$(I)$ It exhibits neoteny and paedogenesis.
$(II)$ The absence of thyroxine affects metamorphosis.
$(III)$ It is a hemichordate larva.