Final answer:
The land bridge that connected the Palearctic and Nearctic regions is called the Bering Land Bridge, or Beringia. It was exposed during the last glaciation when sea levels were lower.
Step-by-step explanation:
The name of the land bridge that connected the Palearctic and Nearctic regions is the Bering Land Bridge. This bridge, better known as Beringia, connected what is now Russia and Alaska during the ice ages when sea levels were significantly lower. The earliest inhabitants of the Americas are believed to have crossed this land bridge in pursuit of food and following migratory herds, around 18,000 years ago, when Beringia was exposed due to glacial ice formation on the continents. The Bering Land Bridge became submerged and eventually formed the Bering Strait when the sea level rose as the glaciers melted.