Answer:
When there is a mistake in the copying of the genetic message that is permanent, a mutation has occurred. Two of the bases in DNA (Cytosine and Thymine) are the most vulnerable, and when this happens, they may pair with each other or themselves and the message is changed.
Explanation:
hope this helps you
Sensory receptors?? I believe that is the answer but you may have wanted a more in depth explanation, if so, my bad.
Answer: Armored fish
Explanation:
The earliest known fossil vertebrates were heavily armored fish discovered fish in rocks from the Ordovician period.
The fossils shows the path from the early aquatic life to the vertebrates, vertebrates to mammals.
The fossils shows that it is vertebrate and are the oldest known fossil ever known. The fossils of the animals and plants helps to known the behavior of the past time and based on that research and study is done.