Birds have a hard time in cold weather, because their body temperatures are higher than those of humans They provide warmth and insulation against colder temperatures. Many birds grow extra feathers in the months leading up to colder weather, so that they'll stay warmer when temperatures drop.
After DNA replication has taken place, two molecules, each with one original and new strand is formed. This supports the idea of DNA replication.
This means that a single carbon atom can form up to tetravalent bonds with other atoms
