Hydra has a receptor Q in certain cell/s that respond to a specific neurotransmitter P1, isolated from brains of higher mammals. An experimenter finds that many species have neurotransmitters that are structurally related to P 1 and have functional homologs of receptor Q . Binding of P to Q elicits neuronal response. A summary of this study is given below.
$\begin{array}{|c|c|c|} \hline \text{species} & \text{number of Q genes} & \text{response to P group (P1 to P4) of molecules} \\ \hline \text{Hydra} & 1 & \text{Yes (only to P1)} \\ \hline \text{Worms} & 1 & \text{Yes (only to P1)} \\ \hline \text{Insects} & 0 & \text{No response to P1, P2, P3, P4} \\ \hline \text{Fishes} & 1 & \text{Yes (only to P1)} \\ \hline \text{Amphibians} & 2 & \text{Yes (only to P1 and P3)} \\ \hline \text{Reptiles} & 3 & \text{Yes (only to P3 and P4)} \\ \hline \text{Birds} & 4 & \text{Yes (only to P3 and P4)} \\ \hline \text{Mammals} & 5 & \text{Yes (only to P1, P2, P4)} \\ \hline \end{array}$
Based on this information choose the statement(s) that is(are) likely to be correct.

• A

  In mammals, P3 can compete with P1, P2, P4 for eliciting the response.
• Correct answer
  B

  Insects might have lost the gene $\mathbf{Q}$ due to the loss of endogenous production of $\mathbf{P}$ group of neurotransmitters.
• Correct answer
  C

  Insects have lost the gene Q after fish have evolved.
• Correct answer
  D

  In mammals, the Q gene multiplication occurred as a result of diversification of the neurotransmitter $\mathbf{P}$.

Hence, the correct answer is options: 'B', 'C', 'D'.