Question $1$

What is true about network models?

$1$ point

Protein$-$protein interaction models have nodes as proteins, which are connected by edges, only if the proteins show functional redundancy.

Gene co$-$expression networks have genes as nodes, which are connected by edges, if their expression correlate under different conditions.

Graph theory analysis of network models was developed in response to the systems biological approach of understanding cellular systems.

Network models do not allow directed interactions.

There are no computational tools for the analysis of networks online.