Does ETH2.0 node need to be a ETH1.0 node, too?

The ETH2.0 spec says that for a beacon chain block, to be processed by a node, the following condition must be met (amongst others):

"The Ethereum 1.0 block pointed to by the state.processed_pow_receipt_root has been processed and accepted."

I understand why this is necessary. My question is how the ETH2.0 node most efficiently gets this information.

Submitted December 28, 2018 at 04:33AM }
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