Question: Are network cards and IP addresses a one-one map?

Answer: 
Not only is this possible, it is very common. A network card may have multiple IP addresses. This is a concept called [multihoming](http://en.wikipedia.org/wiki/Multihoming). There are other variants of multihoming as well.
A very common example of one NIC with multiple IP addresses is where the NIC provides a management interface in addition to what the OS sees. e.g. HP servers with ILO.