AND gate IC with internal pullup
The inputs of bipolar TTL logic (74xx, 74LSxx) normallly appear as High when not connected - but even with them, it is advised to provide a pull-up resistor to ensure that unconnected inputs will really be taken as High.

CMOS parts (74HCxx, 74ACxx, etc.) have very high input impedances, and MUST have a pull-up or pull-down resistor to be reliably detected as High or Low, respectively.

Added, following a "not an answer" comment:

I'm not aware of any common logic parts (gates, flipflops, counters...) that have built-in pull-up resistors on their inputs, but many microcontrollers do have pull-up resistors that can be enabled or disabled by software on their I/O pins.