Which term is used to descibe body structures that look alike and serve a similar function but are not descended from a common ancestor?

There are six elements that make up most of the human body. which of the following is not one of these six elements?

The theories on the expansion of galaxies maybe re-examined to strengthen science should not be tested to strengthen science will weaken scientific knowledge if they change will become laws if they don't change

Explain how the number of similarities between the embryos from early stage to late stage is used as evidence of a common ancestry