<span>selective breeding </span>because people are breeding new things.
Making kids or reproduction(sex)
The protein hemoglobin. <span />
Answer:
amino acids
Explanation:
The building blocks of proteins are amino acids, which are small organic molecules that consist of an alpha (central) carbon atom linked to an amino group, a carboxyl group, a hydrogen atom, and a variable component called a side chain.
Hope this helps :)
I really, really think it might be C. because they both can, only flat worms live in intestines and and roundworms have a pseudocoelom not a coelom. B also through me off because flat worms are symmetric.