<span>an animal embryo at the early stage of development when it is a hollow ball of cells.</span>
A protein that has the same function as another protein but which is encoded by a different gene and may have small differences in its sequence
The Answer is B i just took the test. Enjoy, i also just looked it up on a quizlet. That's another website you can use if it comes up in the search for the question.
It's called radioactive dating
