Answer:
B
Explanation:
because their structures become more complex. Such as the human brain, over time we get more knowledge.
I would say that many of our heritable traits are <span>influenced by several genes and by the environnement.
It's, for the biggest part, because of the mutations. You have your heritables traits thanks to your mom and your dad. But a mutation caused by either several rays like ultraviolets or chemicals can changed your traits.
Hope this helps !
Photon</span>
Answer:
Oral poliovirus vaccine or Sabin vaccine, named for its inventor American physician and microbiologist Albert Sabin, was developed. OPV contains live attenuated (weakened) virus and is given orally.