Blockchain or Cryptocurrency are the two sides of a coin if one is the head and the other is the tail.It means both are co-related. They can't exist without each other.
What are you talking about?
Coin is a part of cryptocurrency. What do you think when you said cryptocurrency is a side of coin?
Blockchain can exist without cryptocurrency. Cryptocurrency is one of utilization of blockchain technology.
I have no idea about cryptocurrency exist without blockchain. But I think blockchain is a best technology for cryptocurrency transactions now.