Roundworms have taken this last body plan and adapted to thousands of environments with it. From microscopic to maybe a meter long, roundworms are just what they sound like-round worms. At one end, they have a mouth, at the other, an anus, with a tube digestive system in between.
Availability of two-factor authentication for Apple ID Two-factor authentication is an extra layer of security for your Apple ID designed to ensure that you're the only person who can access your account, even if someone knows your password.
Two-Factor Authentication using Tivoli Access Manager WebSEAL. Single factor authentication such as password authentication is in many cases no longer considered as secure in the Internet world as users like to use easy-to-remember and hence easy-to-guess passwords, such as date of birth, children or family members' name, pet's name, etc.