The largest amount of yolk is found in the egg of

The question is asking about which type of animal has the largest amount of yolk in its egg. Yolk is the part of the egg that provides nutrients to the developing embryo. The options given are amphibians, pisces, reptiles, and aves (which means birds).

Out of these options, the correct answer is aves, or birds. Birds are known for having eggs with a large amount of yolk, which is necessary to provide enough nutrients for the growing embryo. This is because birds develop inside hard-shelled eggs, which need to provide enough nutrients to support their growth until they hatch.

While all of the options given are types of animals that lay eggs, amphibians and pisces typically lay eggs with less yolk. Reptiles, on the other hand, can have eggs with a significant amount of yolk, but not as much as birds.

So, in summary, the animal with the largest amount of yolk in its egg is birds, because they need the extra nutrients to support the development of their young inside their hard-shelled eggs.