I believe the answer is comparative anatomy. It is the study of the similarities and differences in the structures of different species. Similar body parts may be homologies or analogies, such that both provide evidence of evolution. Similarities in embryos are evidence of common ancestry. For example all vertebrates embryos have gill slits and tails.
<span>sperm and egg cells uniting to produce fertilized eggs</span>
A stationary front is the least likely to be associated with rainfall.
The tiny solid particles which play in the cloud formation are solvents.
