Similarities in the bones of the human arm and a whale's flipper suggest what about these organisms?
a.) they have the same dna.
b.) they have nothing in common.
c.) they share a common ancestor.
d.) whales evolved from humans.

They share a common ancestor which is one of the ecological concepts of common descent

after receiving a stimus, the sensory receptors send(s) signals to the appropriate area of the body.  

the must be sensory neurons.  

hope its .

•there must be variation for the particular trait within a population.

•the variation must be inheritable (that is, it must be capable of being passed on from the parents to their offspring).

•individuals with one version of the trait must produce more offspring than those with a different version of the trait.good

explanation: