EVERYDAY SCIENCE

Detailed explanation-1: -Viruses are much smaller. The largest of them are smaller than the smallest bacteria. Unlike bacteria, viruses can’t survive without a host. They can only reproduce by attaching themselves to cells.

Detailed explanation-2: -Viruses are even smaller than bacteria. They aren’t even a full cell. They are simply genetic material (DNA or RNA) packaged inside of a protein coating. They need to use another cell’s structures to reproduce.

Detailed explanation-3: -There are things out there even smaller than viruses. The two that scientists have discovered are called prions and viroids. A prion is (as far as we know) just a protein. Prions are proteins that can invade cells and somehow direct their own duplication, making more of the isolated proteins.

Detailed explanation-4: -And viruses are smaller again-they’re about a hundredth the size of our cells. So we’re about 100, 000 times bigger than our cells, a million times bigger than bacteria, and 10 million times bigger than your average virus!

Detailed explanation-5: -On a biological level, the main difference is that bacteria are free-living cells that can live inside or outside a body, while viruses are a non-living collection of molecules that need a host to survive.