What is absent in "negative" blood types like O negative and AB negative?

More Questions:

In which gymnastics discipline would a man do the scissors?

Which type of prepared bread is named after an opera singer?

What does a spermologer collect?

What company produced the Cabbage Patch Kids dolls until 1989?

What famous horse belonged to Don Quixote?

What creatures in "The Lord of the Rings" are referred to as goblins in the book "The Hobbit"?

What novel's long-promised sequel is called "Buttercup's Baby"?

What woman's rise to fame is the subject of the 1997 book "Just Desserts"?

In The Simpsons, what is the name of Kirk Van Houten's demo singing tape?

What is the name of Simba's uncle in the movie "The Lion King"?

What classic TV show's main family had children named Betty, Kathy, and Bud?

What was Buddy Holly's backing band?

What popular radio DJ was the original voice of Shaggy on "Scooby-Doo"?

Where in Scotland did the massacre of the Macdonald clan take place?

What sank the Titanic?