Which description best explains Watson and Crick's DNA model?

A.

DNA is a single–stranded molecule that has nitrogenous bases toward its exterior.

B.

DNA is a double helix made of two strands linked together with hydrogen bonds.

C.

DNA is a double helix that contains nitrogenous bases toward its exterior

Which best describes the scientific process

Answers to mastering biology drag the labels to their appropriate locations to complete the punnett squares for morgan's reciprocal cross. drag blue labels onto the blue targets to indicate the genotypes of the parents and offspring. drag pink labels onto the pink targets to indicate the genetic makeup of the gametes (sperm and egg). labels can be used once, more than once, or not at all. hints

What is the one part of the nucleotide  that differs among the other different nucle  tides?