Answer:
size and amount of yolk
Explanation:
The main difference between the eggs of a frog, bird and mammals is their size. The size of frog egg is small as compared to bird and mammals. Egg laying mammals have bigger egg . The similarities between eggs of frog, bird and egg laying mammals is the high amount of yolk in the egg which is used as a source of food by the embryo that is present inside the egg during the developmental stages.
